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2016-07-07perf/core: Fix pmu::filter_match for SW-led groupsMark Rutland
The following commit: 66eb579e66ec ("perf: allow for PMU-specific event filtering") added the pmu::filter_match() callback. This was intended to avoid HW constraints on events from resulting in extremely pessimistic scheduling. However, pmu::filter_match() is only called for the leader of each event group. When the leader is a SW event, we do not filter the groups, and may fail at pmu::add() time, and when this happens we'll give up on scheduling any event groups later in the list until they are rotated ahead of the failing group. This can result in extremely sub-optimal event scheduling behaviour, e.g. if running the following on a big.LITTLE platform: $ taskset -c 0 ./perf stat \ -e 'a57{context-switches,armv8_cortex_a57/config=0x11/}' \ -e 'a53{context-switches,armv8_cortex_a53/config=0x11/}' \ ls <not counted> context-switches (0.00%) <not counted> armv8_cortex_a57/config=0x11/ (0.00%) 24 context-switches (37.36%) 57589154 armv8_cortex_a53/config=0x11/ (37.36%) Here the 'a53' event group was always eligible to be scheduled, but the 'a57' group never eligible to be scheduled, as the task was always affine to a Cortex-A53 CPU. The SW (group leader) event in the 'a57' group was eligible, but the HW event failed at pmu::add() time, resulting in ctx_flexible_sched_in giving up on scheduling further groups with HW events. One way of avoiding this is to check pmu::filter_match() on siblings as well as the group leader. If any of these fail their pmu::filter_match() call, we must skip the entire group before attempting to add any events. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Fixes: 66eb579e66ec ("perf: allow for PMU-specific event filtering") Link: http://lkml.kernel.org/r/1465917041-15339-1-git-send-email-mark.rutland@arm.com [ Small readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-06-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: "I've been traveling so this accumulates more than week or so of bug fixing. It perhaps looks a little worse than it really is. 1) Fix deadlock in ath10k driver, from Ben Greear. 2) Increase scan timeout in iwlwifi, from Luca Coelho. 3) Unbreak STP by properly reinjecting STP packets back into the stack. Regression fix from Ido Schimmel. 4) Mediatek driver fixes (missing malloc failure checks, leaking of scratch memory, wrong indexing when mapping TX buffers, etc.) from John Crispin. 5) Fix endianness bug in icmpv6_err() handler, from Hannes Frederic Sowa. 6) Fix hashing of flows in UDP in the ruseport case, from Xuemin Su. 7) Fix netlink notifications in ovs for tunnels, delete link messages are never emitted because of how the device registry state is handled. From Nicolas Dichtel. 8) Conntrack module leaks kmemcache on unload, from Florian Westphal. 9) Prevent endless jump loops in nft rules, from Liping Zhang and Pablo Neira Ayuso. 10) Not early enough spinlock initialization in mlx4, from Eric Dumazet. 11) Bind refcount leak in act_ipt, from Cong WANG. 12) Missing RCU locking in HTB scheduler, from Florian Westphal. 13) Several small MACSEC bug fixes from Sabrina Dubroca (missing RCU barrier, using heap for SG and IV, and erroneous use of async flag when allocating AEAD conext.) 14) RCU handling fix in TIPC, from Ying Xue. 15) Pass correct protocol down into ipv4_{update_pmtu,redirect}() in SIT driver, from Simon Horman. 16) Socket timer deadlock fix in TIPC from Jon Paul Maloy. 17) Fix potential deadlock in team enslave, from Ido Schimmel. 18) Memory leak in KCM procfs handling, from Jiri Slaby. 19) ESN generation fix in ipv4 ESP, from Herbert Xu. 20) Fix GFP_KERNEL allocations with locks held in act_ife, from Cong WANG. 21) Use after free in netem, from Eric Dumazet. 22) Uninitialized last assert time in multicast router code, from Tom Goff. 23) Skip raw sockets in sock_diag destruction broadcast, from Willem de Bruijn. 24) Fix link status reporting in thunderx, from Sunil Goutham. 25) Limit resegmentation of retransmit queue so that we do not retransmit too large GSO frames. From Eric Dumazet. 26) Delay bpf program release after grace period, from Daniel Borkmann" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (141 commits) openvswitch: fix conntrack netlink event delivery qed: Protect the doorbell BAR with the write barriers. neigh: Explicitly declare RCU-bh read side critical section in neigh_xmit() e1000e: keep VLAN interfaces functional after rxvlan off cfg80211: fix proto in ieee80211_data_to_8023 for frames without LLC header qlcnic: use the correct ring in qlcnic_83xx_process_rcv_ring_diag() bpf, perf: delay release of BPF prog after grace period net: bridge: fix vlan stats continue counter tcp: do not send too big packets at retransmit time ibmvnic: fix to use list_for_each_safe() when delete items net: thunderx: Fix TL4 configuration for secondary Qsets net: thunderx: Fix link status reporting net/mlx5e: Reorganize ethtool statistics net/mlx5e: Fix number of PFC counters reported to ethtool net/mlx5e: Prevent adding the same vxlan port net/mlx5e: Check for BlueFlame capability before allocating SQ uar net/mlx5e: Change enum to better reflect usage net/mlx5: Add ConnectX-5 PCIe 4.0 to list of supported devices net/mlx5: Update command strings net: marvell: Add separate config ANEG function for Marvell 88E1111 ...
2016-06-29bpf, perf: delay release of BPF prog after grace periodDaniel Borkmann
Commit dead9f29ddcc ("perf: Fix race in BPF program unregister") moved destruction of BPF program from free_event_rcu() callback to __free_event(), which is problematic if used with tail calls: if prog A is attached as trace event directly, but at the same time present in a tail call map used by another trace event program elsewhere, then we need to delay destruction via RCU grace period since it can still be in use by the program doing the tail call (the prog first needs to be dropped from the tail call map, then trace event with prog A attached destroyed, so we get immediate destruction). Fixes: dead9f29ddcc ("perf: Fix race in BPF program unregister") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: Jann Horn <jann@thejh.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-10Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "A handful of tooling fixes, two PMU driver fixes and a cleanup of redundant code that addresses a security analyzer false positive" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Remove a redundant check perf/x86/intel/uncore: Remove SBOX support for Broadwell server perf ctf: Convert invalid chars in a string before set value perf record: Fix crash when kptr is restricted perf symbols: Check kptr_restrict for root perf/x86/intel/rapl: Fix pmus free during cleanup
2016-06-08perf/core: Remove a redundant checkAlexander Shishkin
There is no way to end up in _free_event() with event::pmu being NULL. The latter is initialized in event allocation path and remains set forever. In case of allocation failure, the error path doesn't use _free_event(). Having the check, however, suggests that it is possible to have a event::pmu==NULL situation in _free_event() and confuses the robots. This patch gets rid of the check. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: eranian@google.com Cc: vince@deater.net Link: http://lkml.kernel.org/r/1465303455-26032-1-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-25Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Mostly tooling and PMU driver fixes, but also a number of late updates such as the reworking of the call-chain size limiting logic to make call-graph recording more robust, plus tooling side changes for the new 'backwards ring-buffer' extension to the perf ring-buffer" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits) perf record: Read from backward ring buffer perf record: Rename variable to make code clear perf record: Prevent reading invalid data in record__mmap_read perf evlist: Add API to pause/resume perf trace: Use the ptr->name beautifier as default for "filename" args perf trace: Use the fd->name beautifier as default for "fd" args perf report: Add srcline_from/to branch sort keys perf evsel: Record fd into perf_mmap perf evsel: Add overwrite attribute and check write_backward perf tools: Set buildid dir under symfs when --symfs is provided perf trace: Only auto set call-graph to "dwarf" when syscalls are being traced perf annotate: Sort list of recognised instructions perf annotate: Fix identification of ARM blt and bls instructions perf tools: Fix usage of max_stack sysctl perf callchain: Stop validating callchains by the max_stack sysctl perf trace: Fix exit_group() formatting perf top: Use machine->kptr_restrict_warned perf trace: Warn when trying to resolve kernel addresses with kptr_restrict=1 perf machine: Do not bail out if not managing to read ref reloc symbol perf/x86/intel/p4: Trival indentation fix, remove space ...
2016-05-23uprobes: wait for mmap_sem for write killableMichal Hocko
xol_add_vma needs mmap_sem for write. If the waiting task gets killed by the oom killer it would block oom_reaper from asynchronous address space reclaim and reduce the chances of timely OOM resolving. Wait for the lock in the killable mode and return with EINTR if the task got killed while waiting. Do not warn in dup_xol_work if __create_xol_area failed due to fatal signal pending because this is usually considered a kernel issue. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-22x86: remove more uaccess_32.h complexityLinus Torvalds
I'm looking at trying to possibly merge the 32-bit and 64-bit versions of the x86 uaccess.h implementation, but first this needs to be cleaned up. For example, the 32-bit version of "__copy_from_user_inatomic()" is mostly the special cases for the constant size, and it's actually almost never relevant. Most users aren't actually using a constant size anyway, and the few cases that do small constant copies are better off just using __get_user() instead. So get rid of the unnecessary complexity. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-nextLinus Torvalds
Pull networking updates from David Miller: "Highlights: 1) Support SPI based w5100 devices, from Akinobu Mita. 2) Partial Segmentation Offload, from Alexander Duyck. 3) Add GMAC4 support to stmmac driver, from Alexandre TORGUE. 4) Allow cls_flower stats offload, from Amir Vadai. 5) Implement bpf blinding, from Daniel Borkmann. 6) Optimize _ASYNC_ bit twiddling on sockets, unless the socket is actually using FASYNC these atomics are superfluous. From Eric Dumazet. 7) Run TCP more preemptibly, also from Eric Dumazet. 8) Support LED blinking, EEPROM dumps, and rxvlan offloading in mlx5e driver, from Gal Pressman. 9) Allow creating ppp devices via rtnetlink, from Guillaume Nault. 10) Improve BPF usage documentation, from Jesper Dangaard Brouer. 11) Support tunneling offloads in qed, from Manish Chopra. 12) aRFS offloading in mlx5e, from Maor Gottlieb. 13) Add RFS and RPS support to SCTP protocol, from Marcelo Ricardo Leitner. 14) Add MSG_EOR support to TCP, this allows controlling packet coalescing on application record boundaries for more accurate socket timestamp sampling. From Martin KaFai Lau. 15) Fix alignment of 64-bit netlink attributes across the board, from Nicolas Dichtel. 16) Per-vlan stats in bridging, from Nikolay Aleksandrov. 17) Several conversions of drivers to ethtool ksettings, from Philippe Reynes. 18) Checksum neutral ILA in ipv6, from Tom Herbert. 19) Factorize all of the various marvell dsa drivers into one, from Vivien Didelot 20) Add VF support to qed driver, from Yuval Mintz" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1649 commits) Revert "phy dp83867: Fix compilation with CONFIG_OF_MDIO=m" Revert "phy dp83867: Make rgmii parameters optional" r8169: default to 64-bit DMA on recent PCIe chips phy dp83867: Make rgmii parameters optional phy dp83867: Fix compilation with CONFIG_OF_MDIO=m bpf: arm64: remove callee-save registers use for tmp registers asix: Fix offset calculation in asix_rx_fixup() causing slow transmissions switchdev: pass pointer to fib_info instead of copy net_sched: close another race condition in tcf_mirred_release() tipc: fix nametable publication field in nl compat drivers: net: Don't print unpopulated net_device name qed: add support for dcbx. ravb: Add missing free_irq() calls to ravb_close() qed: Remove a stray tab net: ethernet: fec-mpc52xx: use phy_ethtool_{get|set}_link_ksettings net: ethernet: fec-mpc52xx: use phydev from struct net_device bpf, doc: fix typo on bpf_asm descriptions stmmac: hardware TX COE doesn't work when force_thresh_dma_mode is set net: ethernet: fs-enet: use phy_ethtool_{get|set}_link_ksettings net: ethernet: fs-enet: use phydev from struct net_device ...
2016-05-16perf core: Separate accounting of contexts and real addresses in a stack traceArnaldo Carvalho de Melo
The perf_sample->ip_callchain->nr value includes all the entries in the ip_callchain->ip[] array, real addresses and PERF_CONTEXT_{KERNEL,USER,etc}, while what the user expects is that what is in the kernel.perf_event_max_stack sysctl or in the upcoming per event perf_event_attr.sample_max_stack knob be honoured in terms of IP addresses in the stack trace. So allocate a bunch of extra entries for contexts, and do the accounting via perf_callchain_entry_ctx struct members. A new sysctl, kernel.perf_event_max_contexts_per_stack is also introduced for investigating possible bugs in the callchain implementation by some arch. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/n/tip-3b4wnqk340c4sg4gwkfdi9yk@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-16perf core: Add perf_callchain_store_context() helperArnaldo Carvalho de Melo
We need have different helpers to account how many contexts we have in the sample and for real addresses, so do it now as a prep patch, to ease review. Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-q964tnyuqrxw5gld18vizs3c@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-16perf core: Add a 'nr' field to perf_event_callchain_contextArnaldo Carvalho de Melo
We will use it to count how many addresses are in the entry->ip[] array, excluding PERF_CONTEXT_{KERNEL,USER,etc} entries, so that we can really return the number of entries specified by the user via the relevant sysctl, kernel.perf_event_max_contexts, or via the per event perf_event_attr.sample_max_stack knob. This way we keep the perf_sample->ip_callchain->nr meaning, that is the number of entries, be it real addresses or PERF_CONTEXT_ entries, while honouring the max_stack knobs, i.e. the end result will be max_stack entries if we have at least that many entries in a given stack trace. Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-s8teto51tdqvlfhefndtat9r@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-16perf core: Pass max stack as a perf_callchain_entry contextArnaldo Carvalho de Melo
This makes perf_callchain_{user,kernel}() receive the max stack as context for the perf_callchain_entry, instead of accessing the global sysctl_perf_event_max_stack. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-16perf core: Generalize max_stack sysctl handlerArnaldo Carvalho de Melo
So that it can be used for other stack related knobs, such as the upcoming one to tweak the max number of of contexts per stack sample. In all those cases we can only change the value if there are no perf sessions collecting stacks, so they need to grab that mutex, etc. Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-8t3fk94wuzp8m2z1n4gc0s17@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-05-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
The nf_conntrack_core.c fix in 'net' is not relevant in 'net-next' because we no longer have a per-netns conntrack hash. The ip_gre.c conflict as well as the iwlwifi ones were cases of overlapping changes. Conflicts: drivers/net/wireless/intel/iwlwifi/mvm/tx.c net/ipv4/ip_gre.c net/netfilter/nf_conntrack_core.c Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-12perf/core: Disable the event on a truncated AUX recordAlexander Shishkin
When the PMU driver reports a truncated AUX record, it effectively means that there is no more usable room in the event's AUX buffer (even though there may still be some room, so that perf_aux_output_begin() doesn't take action). At this point the consumer still has to be woken up and the event has to be disabled, otherwise the event will just keep spinning between perf_aux_output_begin() and perf_aux_output_end() until its context gets unscheduled. Again, for cpu-wide events this means never, so once in this condition, they will be forever losing data. Fix this by disabling the event and waking up the consumer in case of a truncated AUX record. Reported-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1462886313-13660-3-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-12perf/core: Disable the event on a truncated AUX recordAlexander Shishkin
When the PMU driver reports a truncated AUX record, it effectively means that there is no more usable room in the event's AUX buffer (even though there may still be some room, so that perf_aux_output_begin() doesn't take action). At this point the consumer still has to be woken up and the event has to be disabled, otherwise the event will just keep spinning between perf_aux_output_begin() and perf_aux_output_end() until its context gets unscheduled. Again, for cpu-wide events this means never, so once in this condition, they will be forever losing data. Fix this by disabling the event and waking up the consumer in case of a truncated AUX record. Reported-by: Markus Metzger <markus.t.metzger@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1462886313-13660-3-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-11Merge branch 'perf/urgent' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-09perf/core: Change the default paranoia level to 2Andy Lutomirski
Allowing unprivileged kernel profiling lets any user dump follow kernel control flow and dump kernel registers. This most likely allows trivial kASLR bypassing, and it may allow other mischief as well. (Off the top of my head, the PERF_SAMPLE_REGS_INTR output during /dev/urandom reads could be quite interesting.) Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-05perf/arm: Special-case hetereogeneous CPUsMark Rutland
Commit: 26657848502b7847 ("perf/core: Verify we have a single perf_hw_context PMU") forcefully prevents multiple PMUs from sharing perf_hw_context, as this generally doesn't make sense. It is a common bug for uncore PMUs to use perf_hw_context rather than perf_invalid_context, which this detects. However, systems exist with heterogeneous CPUs (and hence heterogeneous HW PMUs), for which sharing perf_hw_context is necessary, and possible in some limited cases. To make this work we have to perform some gymnastics, as we did in these commits: 66eb579e66ecfea5 ("perf: allow for PMU-specific event filtering") c904e32a69b7c779 ("arm: perf: filter unschedulable events") To allow those systems to work, we must allow PMUs for heterogeneous CPUs to share perf_hw_context, though we must still disallow sharing otherwise to detect the common misuse of perf_hw_context. This patch adds a new PERF_PMU_CAP_HETEROGENEOUS_CPUS for this, updates the core logic to account for this, and makes use of it in the arm_pmu code that is used for systems with heterogeneous CPUs. Comments are added to make the rationale clear and hopefully avoid accidental abuse. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20160426103346.GA20836@leverpostej Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-05perf/core: Let userspace know if the PMU supports address filtersAlexander Shishkin
Export an additional common attribute for PMUs that support address range filtering to let the perf userspace identify such PMUs in a uniform way. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1461771888-10409-8-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-05perf/core: Introduce address range filteringAlexander Shishkin
Many instruction tracing PMUs out there support address range-based filtering, which would, for example, generate trace data only for a given range of instruction addresses, which is useful for tracing individual functions, modules or libraries. Other PMUs may also utilize this functionality to allow filtering to or filtering out code at certain address ranges. This patch introduces the interface for userspace to specify these filters and for the PMU drivers to apply these filters to hardware configuration. The user interface is an ASCII string that is passed via an ioctl() and specifies (in the form of an ASCII string) address ranges within certain object files or within kernel. There is no special treatment for kernel modules yet, but it might be a worthy pursuit. The PMU driver interface basically adds two extra callbacks to the PMU driver structure, one of which validates the filter configuration proposed by the user against what the hardware is actually capable of doing and the other one translates hardware-independent filter configuration into something that can be programmed into the hardware. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1461771888-10409-6-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-05perf/core: Extend perf_event_aux_ctx() to optionally iterate through more eventsAlexander Shishkin
Trace filtering code needs an iterator that can go through all events in a context, including inactive and filtered, to be able to update their filters' address ranges based on mmap or exec events. This patch changes perf_event_aux_ctx() to optionally do this. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1461771888-10409-5-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-05perf/core: Move set_filter() out of CONFIG_EVENT_TRACINGAlexander Shishkin
For instruction trace filtering, namely, for communicating filter definitions from userspace, I'd like to re-use the SET_FILTER code that the tracepoints are using currently. To that end, move the relevant code out from behind the CONFIG_EVENT_TRACING dependency. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1461771888-10409-2-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/ipv4/ip_gre.c Minor conflicts between tunnel bug fixes in net and ipv6 tunnel cleanups in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28Merge branch 'perf/urgent' into perf/core, to resolve conflictIngo Molnar
Conflicts: arch/x86/events/intel/pt.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28perf/core: Fix perf_event_open() vs. execve() racePeter Zijlstra
Jann reported that the ptrace_may_access() check in find_lively_task_by_vpid() is racy against exec(). Specifically: perf_event_open() execve() ptrace_may_access() commit_creds() ... if (get_dumpable() != SUID_DUMP_USER) perf_event_exit_task(); perf_install_in_context() would result in installing a counter across the creds boundary. Fix this by wrapping lots of perf_event_open() in cred_guard_mutex. This should be fine as perf_event_exit_task() is already called with cred_guard_mutex held, so all perf locks already nest inside it. Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-27perf core: Allow setting up max frame stack depth via sysctlArnaldo Carvalho de Melo
The default remains 127, which is good for most cases, and not even hit most of the time, but then for some cases, as reported by Brendan, 1024+ deep frames are appearing on the radar for things like groovy, ruby. And in some workloads putting a _lower_ cap on this may make sense. One that is per event still needs to be put in place tho. The new file is: # cat /proc/sys/kernel/perf_event_max_stack 127 Chaging it: # echo 256 > /proc/sys/kernel/perf_event_max_stack # cat /proc/sys/kernel/perf_event_max_stack 256 But as soon as there is some event using callchains we get: # echo 512 > /proc/sys/kernel/perf_event_max_stack -bash: echo: write error: Device or resource busy # Because we only allocate the callchain percpu data structures when there is a user, which allows for changing the max easily, its just a matter of having no callchain users at that point. Reported-and-Tested-by: Brendan Gregg <brendan.d.gregg@gmail.com> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: David Ahern <dsahern@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/20160426002928.GB16708@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-04-23perf/core: Add ::write_backward attribute to perf eventWang Nan
This patch introduces 'write_backward' bit to perf_event_attr, which controls the direction of a ring buffer. After set, the corresponding ring buffer is written from end to beginning. This feature is design to support reading from overwritable ring buffer. Ring buffer can be created by mapping a perf event fd. Kernel puts event records into ring buffer, user tooling like perf fetch them from address returned by mmap(). To prevent racing between kernel and tooling, they communicate to each other through 'head' and 'tail' pointers. Kernel maintains 'head' pointer, points it to the next free area (tail of the last record). Tooling maintains 'tail' pointer, points it to the tail of last consumed record (record has already been fetched). Kernel determines the available space in a ring buffer using these two pointers to avoid overwrite unfetched records. By mapping without 'PROT_WRITE', an overwritable ring buffer is created. Different from normal ring buffer, tooling is unable to maintain 'tail' pointer because writing is forbidden. Therefore, for this type of ring buffers, kernel overwrite old records unconditionally, works like flight recorder. This feature would be useful if reading from overwritable ring buffer were as easy as reading from normal ring buffer. However, there's an obscure problem. The following figure demonstrates a full overwritable ring buffer. In this figure, the 'head' pointer points to the end of last record, and a long record 'E' is pending. For a normal ring buffer, a 'tail' pointer would have pointed to position (X), so kernel knows there's no more space in the ring buffer. However, for an overwritable ring buffer, kernel ignore the 'tail' pointer. (X) head . | . V +------+-------+----------+------+---+ |A....A|B.....B|C........C|D....D| | +------+-------+----------+------+---+ Record 'A' is overwritten by event 'E': head | V +--+---+-------+----------+------+---+ |.E|..A|B.....B|C........C|D....D|E..| +--+---+-------+----------+------+---+ Now tooling decides to read from this ring buffer. However, none of these two natural positions, 'head' and the start of this ring buffer, are pointing to the head of a record. Even the full ring buffer can be accessed by tooling, it is unable to find a position to start decoding. The first attempt tries to solve this problem AFAIK can be found from [1]. It makes kernel to maintain 'tail' pointer: updates it when ring buffer is half full. However, this approach introduces overhead to fast path. Test result shows a 1% overhead [2]. In addition, this method utilizes no more tham 50% records. Another attempt can be found from [3], which allows putting the size of an event at the end of each record. This approach allows tooling to find records in a backward manner from 'head' pointer by reading size of a record from its tail. However, because of alignment requirement, it needs 8 bytes to record the size of a record, which is a huge waste. Its performance is also not good, because more data need to be written. This approach also introduces some extra branch instructions to fast path. 'write_backward' is a better solution to this problem. Following figure demonstrates the state of the overwritable ring buffer when 'write_backward' is set before overwriting: head | V +---+------+----------+-------+------+ | |D....D|C........C|B.....B|A....A| +---+------+----------+-------+------+ and after overwriting: head | V +---+------+----------+-------+---+--+ |..E|D....D|C........C|B.....B|A..|E.| +---+------+----------+-------+---+--+ In each situation, 'head' points to the beginning of the newest record. From this record, tooling can iterate over the full ring buffer and fetch records one by one. The only limitation that needs to be considered is back-to-back reading. Due to the non-deterministic of user programs, it is impossible to ensure the ring buffer keeps stable during reading. Consider an extreme situation: tooling is scheduled out after reading record 'D', then a burst of events come, eat up the whole ring buffer (one or multiple rounds). When the tooling process comes back, reading after 'D' is incorrect now. To prevent this problem, we need to find a way to ensure the ring buffer is stable during reading. ioctl(PERF_EVENT_IOC_PAUSE_OUTPUT) is suggested because its overhead is lower than ioctl(PERF_EVENT_IOC_ENABLE). By carefully verifying 'header' pointer, reader can avoid pausing the ring-buffer. For example: /* A union of all possible events */ union perf_event event; p = head = perf_mmap__read_head(); while (true) { /* copy header of next event */ fetch(&event.header, p, sizeof(event.header)); /* read 'head' pointer */ head = perf_mmap__read_head(); /* check overwritten: is the header good? */ if (!verify(sizeof(event.header), p, head)) break; /* copy the whole event */ fetch(&event, p, event.header.size); /* read 'head' pointer again */ head = perf_mmap__read_head(); /* is the whole event good? */ if (!verify(event.header.size, p, head)) break; p += event.header.size; } However, the overhead is high because: a) In-place decoding is not safe. Copying-verifying-decoding is required. b) Fetching 'head' pointer requires additional synchronization. (From Alexei Starovoitov: Even when this trick works, pause is needed for more than stability of reading. When we collect the events into overwrite buffer we're waiting for some other trigger (like all cpu utilization spike or just one cpu running and all others are idle) and when it happens the buffer has valuable info from the past. At this point new events are no longer interesting and buffer should be paused, events read and unpaused until next trigger comes.) This patch utilizes event's default overflow_handler introduced previously. perf_event_output_backward() is created as the default overflow handler for backward ring buffers. To avoid extra overhead to fast path, original perf_event_output() becomes __perf_event_output() and marked '__always_inline'. In theory, there's no extra overhead introduced to fast path. Performance testing: Calling 3000000 times of 'close(-1)', use gettimeofday() to check duration. Use 'perf record -o /dev/null -e raw_syscalls:*' to capture system calls. In ns. Testing environment: CPU : Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz Kernel : v4.5.0 MEAN STDVAR BASE 800214.950 2853.083 PRE1 2253846.700 9997.014 PRE2 2257495.540 8516.293 POST 2250896.100 8933.921 Where 'BASE' is pure performance without capturing. 'PRE1' is test result of pure 'v4.5.0' kernel. 'PRE2' is test result before this patch. 'POST' is test result after this patch. See [4] for the detailed experimental setup. Considering the stdvar, this patch doesn't introduce performance overhead to the fast path. [1] http://lkml.iu.edu/hypermail/linux/kernel/1304.1/04584.html [2] http://lkml.iu.edu/hypermail/linux/kernel/1307.1/00535.html [3] http://lkml.iu.edu/hypermail/linux/kernel/1512.0/01265.html [4] http://lkml.kernel.org/g/56F89DCD.1040202@huawei.com Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: <acme@kernel.org> Cc: <pi3orama@163.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/1459865478-53413-1-git-send-email-wangnan0@huawei.com [ Fixed the changelog some more. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-23Merge branch 'perf/urgent' into perf/core, to resolve conflictIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-23perf/core: Make sysctl_perf_cpu_time_max_percent conform to documentationPeter Zijlstra
Markus reported that 0 should also disable the throttling we per Documentation/sysctl/kernel.txt. Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 91a612eea9a3 ("perf/core: Fix dynamic interrupt throttle") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-21perf, bpf: minimize the size of perf_trace_() tracepoint handlerAlexei Starovoitov
move trace_call_bpf() into helper function to minimize the size of perf_trace_*() tracepoint handlers. text data bss dec hex filename 10541679 5526646 2945024 19013349 1221ee5 vmlinux_before 10509422 5526646 2945024 18981092 121a0e4 vmlinux_after It may seem that perf_fetch_caller_regs() can also be moved, but that is incorrect, since ip/sp will be wrong. bpf+tracepoint performance is not affected, since perf_swevent_put_recursion_context() is now inlined. export_symbol_gpl can also be dropped. No measurable change in normal perf tracepoints. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-13Merge tag 'v4.6-rc3' into perf/core, to refresh the treeIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2016-04-07bpf: sanitize bpf tracepoint accessAlexei Starovoitov
during bpf program loading remember the last byte of ctx access and at the time of attaching the program to tracepoint check that the program doesn't access bytes beyond defined in tracepoint fields This also disallows access to __dynamic_array fields, but can be relaxed in the future. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07perf, bpf: allow bpf programs attach to tracepointsAlexei Starovoitov
introduce BPF_PROG_TYPE_TRACEPOINT program type and allow it to be attached to the perf tracepoint handler, which will copy the arguments into the per-cpu buffer and pass it to the bpf program as its first argument. The layout of the fields can be discovered by doing 'cat /sys/kernel/debug/tracing/events/sched/sched_switch/format' prior to the compilation of the program with exception that first 8 bytes are reserved and not accessible to the program. This area is used to store the pointer to 'struct pt_regs' which some of the bpf helpers will use: +---------+ | 8 bytes | hidden 'struct pt_regs *' (inaccessible to bpf program) +---------+ | N bytes | static tracepoint fields defined in tracepoint/format (bpf readonly) +---------+ | dynamic | __dynamic_array bytes of tracepoint (inaccessible to bpf yet) +---------+ Not that all of the fields are already dumped to user space via perf ring buffer and broken application access it directly without consulting tracepoint/format. Same rule applies here: static tracepoint fields should only be accessed in a format defined in tracepoint/format. The order of fields and field sizes are not an ABI. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-07perf: split perf_trace_buf_prepare into alloc and update partsAlexei Starovoitov
split allows to move expensive update of 'struct trace_entry' to later phase. Repurpose unused 1st argument of perf_tp_event() to indicate event type. While splitting use temp variable 'rctx' instead of '*rctx' to avoid unnecessary loads done by the compiler due to -fno-strict-aliasing Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-04Merge branch 'PAGE_CACHE_SIZE-removal'Linus Torvalds
Merge PAGE_CACHE_SIZE removal patches from Kirill Shutemov: "PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. Let's stop pretending that pages in page cache are special. They are not. The first patch with most changes has been done with coccinelle. The second is manual fixups on top. The third patch removes macros definition" [ I was planning to apply this just before rc2, but then I spaced out, so here it is right _after_ rc2 instead. As Kirill suggested as a possibility, I could have decided to only merge the first two patches, and leave the old interfaces for compatibility, but I'd rather get it all done and any out-of-tree modules and patches can trivially do the converstion while still also working with older kernels, so there is little reason to try to maintain the redundant legacy model. - Linus ] * PAGE_CACHE_SIZE-removal: mm: drop PAGE_CACHE_* and page_cache_{get,release} definition mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-03Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc kernel side fixes: - fix event leak - fix AMD PMU driver bug - fix core event handling bug - fix build bug on certain randconfigs Plus misc tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/amd/ibs: Fix pmu::stop() nesting perf/core: Don't leak event in the syscall error path perf/core: Fix time tracking bug with multiplexing perf jit: genelf makes assumptions about endian perf hists: Fix determination of a callchain node's childlessness perf tools: Add missing initialization of perf_sample.cpumode in synthesized samples perf tools: Fix build break on powerpc perf/x86: Move events_sysfs_show() outside CPU_SUP_INTEL perf bench: Fix detached tarball building due to missing 'perf bench memcpy' headers perf tests: Fix tarpkg build test error output redirection
2016-03-31perf/ring_buffer: Prepare writing into the ring-buffer from the endWang Nan
Convert perf_output_begin() to __perf_output_begin() and make the later function able to write records from the end of the ring-buffer. Following commits will utilize the 'backward' flag. This is the core patch to support writing to the ring-buffer backwards, which will be introduced by upcoming patches to support reading from overwritable ring-buffers. In theory, this patch should not introduce any extra performance overhead since we use always_inline, but it does not hurt to double check that assumption: When CONFIG_OPTIMIZE_INLINING is disabled, the output object is nearly identical to original one. See: http://lkml.kernel.org/g/56F52E83.70409@huawei.com When CONFIG_OPTIMIZE_INLINING is enabled, the resuling object file becomes smaller: $ size kernel/events/ring_buffer.o* text data bss dec hex filename 4641 4 8 4653 122d kernel/events/ring_buffer.o.old 4545 4 8 4557 11cd kernel/events/ring_buffer.o.new Performance testing results: Calling 3000000 times of 'close(-1)', use gettimeofday() to check duration. Use 'perf record -o /dev/null -e raw_syscalls:*' to capture system calls. In ns. Testing environment: CPU : Intel(R) Core(TM) i7-4790 CPU @ 3.60GHz Kernel : v4.5.0 MEAN STDVAR BASE 800214.950 2853.083 PRE 2253846.700 9997.014 POST 2257495.540 8516.293 Where 'BASE' is pure performance without capturing. 'PRE' is test result of pure 'v4.5.0' kernel. 'POST' is test result after this patch. Considering the stdvar, this patch doesn't hurt performance, within noise margin. For testing details, see: http://lkml.kernel.org/g/56F89DCD.1040202@huawei.com Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <pi3orama@163.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/1459147292-239310-4-git-send-email-wangnan0@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31perf/core: Set event's default ::overflow_handler()Wang Nan
Set a default event->overflow_handler in perf_event_alloc() so don't need to check event->overflow_handler in __perf_event_overflow(). Following commits can give a different default overflow_handler. Initial idea comes from Peter: http://lkml.kernel.org/r/20130708121557.GA17211@twins.programming.kicks-ass.net Since the default value of event->overflow_handler is not NULL, existing 'if (!overflow_handler)' checks need to be changed. is_default_overflow_handler() is introduced for this. No extra performance overhead is introduced into the hot path because in the original code we still need to read this handler from memory. A conditional branch is avoided so actually we remove some instructions. Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <pi3orama@163.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/1459147292-239310-3-git-send-email-wangnan0@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31perf/ring_buffer: Introduce new ioctl options to pause and resume the ↵Wang Nan
ring-buffer Add new ioctl() to pause/resume ring-buffer output. In some situations we want to read from the ring-buffer only when we ensure nothing can write to the ring-buffer during reading. Without this patch we have to turn off all events attached to this ring-buffer to achieve this. This patch is a prerequisite to enable overwrite support for the perf ring-buffer support. Following commits will introduce new methods support reading from overwrite ring buffer. Before reading, caller must ensure the ring buffer is frozen, or the reading is unreliable. Signed-off-by: Wang Nan <wangnan0@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <pi3orama@163.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/r/1459147292-239310-2-git-send-email-wangnan0@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31perf/ring_buffer: Document AUX API usageAlexander Shishkin
In order to ensure safe AUX buffer management, we rely on the assumption that pmu::stop() stops its ongoing AUX transaction and not just the hw. This patch documents this requirement for the perf_aux_output_{begin,end}() APIs. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1457098969-21595-4-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31perf/core: Free AUX pages in unmap pathAlexander Shishkin
Now that we can ensure that when ring buffer's AUX area is on the way to getting unmapped new transactions won't start, we only need to stop all events that can potentially be writing aux data to our ring buffer. Having done that, we can safely free the AUX pages and corresponding PMU data, as this time it is guaranteed to be the last aux reference holder. This partially reverts: 57ffc5ca679 ("perf: Fix AUX buffer refcounting") ... which was made to defer deallocation that was otherwise possible from an NMI context. Now it is no longer the case; the last call to rb_free_aux() that drops the last AUX reference has to happen in perf_mmap_close() on that AUX area. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/87d1qtz23d.fsf@ashishki-desk.ger.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31perf/ring_buffer: Refuse to begin AUX transaction after rb->aux_mmap_count dropsAlexander Shishkin
When ring buffer's AUX area is unmapped and rb->aux_mmap_count drops to zero, new AUX transactions into this buffer can still be started, even though the buffer in en route to deallocation. This patch adds a check to perf_aux_output_begin() for rb->aux_mmap_count being zero, in which case there is no point starting new transactions, in other words, the ring buffers that pass a certain point in perf_mmap_close will not have their events sending new data, which clears path for freeing those buffers' pages right there and then, provided that no active transactions are holding the AUX reference. Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: vince@deater.net Link: http://lkml.kernel.org/r/1457098969-21595-2-git-send-email-alexander.shishkin@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31perf/core: Verify we have a single perf_hw_context PMUPeter Zijlstra
There should (and can) only be a single PMU for perf_hw_context events. This is because of how we schedule events: once a hardware event fails to schedule (the PMU is 'full') we stop trying to add more. The trivial 'fix' would break the Round-Robin scheduling we do. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31perf/core: Don't leak event in the syscall error pathAlexander Shishkin
In the error path, event_file not being NULL is used to determine whether the event itself still needs to be free'd, so fix it up to avoid leaking. Reported-by: Leon Yu <chianglungyu@gmail.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 130056275ade ("perf: Do not double free") Link: http://lkml.kernel.org/r/87twk06yxp.fsf@ashishki-desk.ger.corp.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31perf/core: Fix time tracking bug with multiplexingPeter Zijlstra
Stephane reported that commit: 3cbaa5906967 ("perf: Fix ctx time tracking by introducing EVENT_TIME") introduced a regression wrt. time tracking, as easily observed by: > This patch introduce a bug in the time tracking of events when > multiplexing is used. > > The issue is easily reproducible with the following perf run: > > $ perf stat -a -C 0 -e branches,branches,branches,branches,branches,branches -I 1000 > 1.000730239 652,394 branches (66.41%) > 1.000730239 597,809 branches (66.41%) > 1.000730239 593,870 branches (66.63%) > 1.000730239 651,440 branches (67.03%) > 1.000730239 656,725 branches (66.96%) > 1.000730239 <not counted> branches > > One branches event is shown as not having run. Yet, with > multiplexing, all events should run especially with a 1s (-I 1000) > interval. The delta for time_running comes out to 0. Yet, the event > has run because the kernel is actually multiplexing the events. The > problem is that the time tracking is the kernel and especially in > ctx_sched_out() is wrong now. > > The problem is that in case that the kernel enters ctx_sched_out() with the > following state: > ctx->is_active=0x7 event_type=0x1 > Call Trace: > [<ffffffff813ddd41>] dump_stack+0x63/0x82 > [<ffffffff81182bdc>] ctx_sched_out+0x2bc/0x2d0 > [<ffffffff81183896>] perf_mux_hrtimer_handler+0xf6/0x2c0 > [<ffffffff811837a0>] ? __perf_install_in_context+0x130/0x130 > [<ffffffff810f5818>] __hrtimer_run_queues+0xf8/0x2f0 > [<ffffffff810f6097>] hrtimer_interrupt+0xb7/0x1d0 > [<ffffffff810509a8>] local_apic_timer_interrupt+0x38/0x60 > [<ffffffff8175ca9d>] smp_apic_timer_interrupt+0x3d/0x50 > [<ffffffff8175ac7c>] apic_timer_interrupt+0x8c/0xa0 > > In that case, the test: > if (is_active & EVENT_TIME) > > will be false and the time will not be updated. Time must always be updated on > sched out. Fix this by always updating time if EVENT_TIME was set, as opposed to only updating time when EVENT_TIME changed. Reported-by: Stephane Eranian <eranian@google.com> Tested-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: kan.liang@intel.com Cc: namhyung@kernel.org Fixes: 3cbaa5906967 ("perf: Fix ctx time tracking by introducing EVENT_TIME") Link: http://lkml.kernel.org/r/20160329072644.GB3408@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-24Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "This tree contains various perf fixes on the kernel side, plus three hw/event-enablement late additions: - Intel Memory Bandwidth Monitoring events and handling - the AMD Accumulated Power Mechanism reporting facility - more IOMMU events ... and a final round of perf tooling updates/fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits) perf llvm: Use strerror_r instead of the thread unsafe strerror one perf llvm: Use realpath to canonicalize paths perf tools: Unexport some methods unused outside strbuf.c perf probe: No need to use formatting strbuf method perf help: Use asprintf instead of adhoc equivalents perf tools: Remove unused perf_pathdup, xstrdup functions perf tools: Do not include stringify.h from the kernel sources tools include: Copy linux/stringify.h from the kernel tools lib traceevent: Remove redundant CPU output perf tools: Remove needless 'extern' from function prototypes perf tools: Simplify die() mechanism perf tools: Remove unused DIE_IF macro perf script: Remove lots of unused arguments perf thread: Rename perf_event__preprocess_sample_addr to thread__resolve perf machine: Rename perf_event__preprocess_sample to machine__resolve perf tools: Add cpumode to struct perf_sample perf tests: Forward the perf_sample in the dwarf unwind test perf tools: Remove misplaced __maybe_unused perf list: Fix documentation of :ppp perf bench numa: Fix assertion for nodes bitfield ...
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