From e1783a240f491fb233f04edc042e16b18a7a79ba Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 5 Jan 2010 15:34:50 +0900 Subject: module: Use this_cpu_xx to dynamically allocate counters Use cpu ops to deal with the per cpu data instead of a local_t. Reduces memory requirements, cache footprint and decreases cycle counts. The this_cpu_xx operations are also used for !SMP mode. Otherwise we could not drop the use of __module_ref_addr() which would make per cpu data handling complicated. this_cpu_xx operations have their own fallback for !SMP. V8-V9: - Leave include asm/module.h since ringbuffer.c depends on it. Nothing else does though. Another patch will deal with that. - Remove spurious free. Signed-off-by: Christoph Lameter Acked-by: Rusty Russell Signed-off-by: Tejun Heo --- include/linux/module.h | 36 ++++++++++++++---------------------- 1 file changed, 14 insertions(+), 22 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 6cb1a3cab5d3..2302f09ea2d9 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -18,6 +18,7 @@ #include #include +#include #include #include @@ -363,11 +364,9 @@ struct module /* Destruction function. */ void (*exit)(void); -#ifdef CONFIG_SMP - char *refptr; -#else - local_t ref; -#endif + struct module_ref { + int count; + } *refptr; #endif #ifdef CONFIG_CONSTRUCTORS @@ -454,25 +453,16 @@ void __symbol_put(const char *symbol); #define symbol_put(x) __symbol_put(MODULE_SYMBOL_PREFIX #x) void symbol_put_addr(void *addr); -static inline local_t *__module_ref_addr(struct module *mod, int cpu) -{ -#ifdef CONFIG_SMP - return (local_t *) (mod->refptr + per_cpu_offset(cpu)); -#else - return &mod->ref; -#endif -} - /* Sometimes we know we already have a refcount, and it's easier not to handle the error case (which only happens with rmmod --wait). */ static inline void __module_get(struct module *module) { if (module) { - unsigned int cpu = get_cpu(); - local_inc(__module_ref_addr(module, cpu)); + preempt_disable(); + __this_cpu_inc(module->refptr->count); trace_module_get(module, _THIS_IP_, - local_read(__module_ref_addr(module, cpu))); - put_cpu(); + __this_cpu_read(module->refptr->count)); + preempt_enable(); } } @@ -481,15 +471,17 @@ static inline int try_module_get(struct module *module) int ret = 1; if (module) { - unsigned int cpu = get_cpu(); + preempt_disable(); + if (likely(module_is_live(module))) { - local_inc(__module_ref_addr(module, cpu)); + __this_cpu_inc(module->refptr->count); trace_module_get(module, _THIS_IP_, - local_read(__module_ref_addr(module, cpu))); + __this_cpu_read(module->refptr->count)); } else ret = 0; - put_cpu(); + + preempt_enable(); } return ret; } -- cgit v1.2.3 From 79615760f380ec86cd58204744e774c33fab9211 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 5 Jan 2010 15:34:50 +0900 Subject: local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.c ringbuffer*.c are the last users of local.h. Remove the include from modules.h and add it to ringbuffer files. Signed-off-by: Christoph Lameter Signed-off-by: Tejun Heo --- include/linux/module.h | 1 - kernel/trace/ring_buffer.c | 1 + kernel/trace/ring_buffer_benchmark.c | 1 + 3 files changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 2302f09ea2d9..7e74ae0051cc 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -17,7 +17,6 @@ #include #include -#include #include #include diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 2326b04c95c4..eb6c8988c31a 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -20,6 +20,7 @@ #include #include +#include #include "trace.h" /* diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c index b2477caf09c2..df74c7982255 100644 --- a/kernel/trace/ring_buffer_benchmark.c +++ b/kernel/trace/ring_buffer_benchmark.c @@ -8,6 +8,7 @@ #include #include #include +#include struct rb_page { u64 ts; -- cgit v1.2.3 From 43cf38eb5cea91245502df3fcee4dbfc1c74dd1c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 2 Feb 2010 14:38:57 +0900 Subject: percpu: add __percpu sparse annotations to core kernel subsystems Add __percpu sparse annotations to core subsystems. These annotations are to make sparse consider percpu variables to be in a different address space and warn if accessed without going through percpu accessors. This patch doesn't affect normal builds. Signed-off-by: Tejun Heo Reviewed-by: Christoph Lameter Acked-by: Paul E. McKenney Cc: Jens Axboe Cc: linux-mm@kvack.org Cc: Rusty Russell Cc: Dipankar Sarma Cc: Peter Zijlstra Cc: Andrew Morton Cc: Eric Biederman --- include/linux/blktrace_api.h | 4 ++-- include/linux/genhd.h | 2 +- include/linux/kexec.h | 2 +- include/linux/mmzone.h | 2 +- include/linux/module.h | 2 +- include/linux/percpu_counter.h | 2 +- include/linux/srcu.h | 2 +- kernel/kexec.c | 2 +- kernel/sched.c | 4 ++-- kernel/stop_machine.c | 2 +- mm/percpu.c | 18 ++++++++++-------- 11 files changed, 22 insertions(+), 20 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index 3b73b9992b26..416bf62d6d46 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -150,8 +150,8 @@ struct blk_user_trace_setup { struct blk_trace { int trace_state; struct rchan *rchan; - unsigned long *sequence; - unsigned char *msg_data; + unsigned long __percpu *sequence; + unsigned char __percpu *msg_data; u16 act_mask; u64 start_lba; u64 end_lba; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 9717081c75ad..56b50514ab25 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -101,7 +101,7 @@ struct hd_struct { unsigned long stamp; int in_flight[2]; #ifdef CONFIG_SMP - struct disk_stats *dkstats; + struct disk_stats __percpu *dkstats; #else struct disk_stats dkstats; #endif diff --git a/include/linux/kexec.h b/include/linux/kexec.h index c356b6914ffd..03e8e8dbc577 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -199,7 +199,7 @@ extern struct kimage *kexec_crash_image; */ extern struct resource crashk_res; typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4]; -extern note_buf_t *crash_notes; +extern note_buf_t __percpu *crash_notes; extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4]; extern size_t vmcoreinfo_size; extern size_t vmcoreinfo_max_size; diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 7874201a3556..41acd4bf7664 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -301,7 +301,7 @@ struct zone { unsigned long min_unmapped_pages; unsigned long min_slab_pages; #endif - struct per_cpu_pageset *pageset; + struct per_cpu_pageset __percpu *pageset; /* * free areas of different sizes */ diff --git a/include/linux/module.h b/include/linux/module.h index 7e74ae0051cc..dd618eb026aa 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -365,7 +365,7 @@ struct module struct module_ref { int count; - } *refptr; + } __percpu *refptr; #endif #ifdef CONFIG_CONSTRUCTORS diff --git a/include/linux/percpu_counter.h b/include/linux/percpu_counter.h index a7684a513994..9bd103c844ee 100644 --- a/include/linux/percpu_counter.h +++ b/include/linux/percpu_counter.h @@ -21,7 +21,7 @@ struct percpu_counter { #ifdef CONFIG_HOTPLUG_CPU struct list_head list; /* All percpu_counters are on a list */ #endif - s32 *counters; + s32 __percpu *counters; }; extern int percpu_counter_batch; diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 4765d97dcafb..41eedccc962c 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -33,7 +33,7 @@ struct srcu_struct_array { struct srcu_struct { int completed; - struct srcu_struct_array *per_cpu_ref; + struct srcu_struct_array __percpu *per_cpu_ref; struct mutex mutex; }; diff --git a/kernel/kexec.c b/kernel/kexec.c index ef077fb73155..87ebe8adc474 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -41,7 +41,7 @@ #include /* Per cpu memory for storing cpu states in case of system crash. */ -note_buf_t* crash_notes; +note_buf_t __percpu *crash_notes; /* vmcoreinfo stuff */ static unsigned char vmcoreinfo_data[VMCOREINFO_BYTES]; diff --git a/kernel/sched.c b/kernel/sched.c index 3a8fb30a91b1..978edfd35a96 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1566,7 +1566,7 @@ static unsigned long cpu_avg_load_per_task(int cpu) #ifdef CONFIG_FAIR_GROUP_SCHED -static __read_mostly unsigned long *update_shares_data; +static __read_mostly unsigned long __percpu *update_shares_data; static void __set_se_shares(struct sched_entity *se, unsigned long shares); @@ -10683,7 +10683,7 @@ struct cgroup_subsys cpu_cgroup_subsys = { struct cpuacct { struct cgroup_subsys_state css; /* cpuusage holds pointer to a u64-type object on every cpu */ - u64 *cpuusage; + u64 __percpu *cpuusage; struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; struct cpuacct *parent; }; diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index 912823e2a11b..9bb9fb1bd79c 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -45,7 +45,7 @@ static int refcount; static struct workqueue_struct *stop_machine_wq; static struct stop_machine_data active, idle; static const struct cpumask *active_cpus; -static void *stop_machine_work; +static void __percpu *stop_machine_work; static void set_state(enum stopmachine_state newstate) { diff --git a/mm/percpu.c b/mm/percpu.c index b336638d20e7..768419d44ad7 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -80,13 +80,15 @@ /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ #ifndef __addr_to_pcpu_ptr #define __addr_to_pcpu_ptr(addr) \ - (void *)((unsigned long)(addr) - (unsigned long)pcpu_base_addr \ - + (unsigned long)__per_cpu_start) + (void __percpu *)((unsigned long)(addr) - \ + (unsigned long)pcpu_base_addr + \ + (unsigned long)__per_cpu_start) #endif #ifndef __pcpu_ptr_to_addr #define __pcpu_ptr_to_addr(ptr) \ - (void *)((unsigned long)(ptr) + (unsigned long)pcpu_base_addr \ - - (unsigned long)__per_cpu_start) + (void __force *)((unsigned long)(ptr) + \ + (unsigned long)pcpu_base_addr - \ + (unsigned long)__per_cpu_start) #endif struct pcpu_chunk { @@ -1065,7 +1067,7 @@ static struct pcpu_chunk *alloc_pcpu_chunk(void) * RETURNS: * Percpu pointer to the allocated area on success, NULL on failure. */ -static void *pcpu_alloc(size_t size, size_t align, bool reserved) +static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) { static int warn_limit = 10; struct pcpu_chunk *chunk; @@ -1194,7 +1196,7 @@ fail_unlock_mutex: * RETURNS: * Percpu pointer to the allocated area on success, NULL on failure. */ -void *__alloc_percpu(size_t size, size_t align) +void __percpu *__alloc_percpu(size_t size, size_t align) { return pcpu_alloc(size, align, false); } @@ -1215,7 +1217,7 @@ EXPORT_SYMBOL_GPL(__alloc_percpu); * RETURNS: * Percpu pointer to the allocated area on success, NULL on failure. */ -void *__alloc_reserved_percpu(size_t size, size_t align) +void __percpu *__alloc_reserved_percpu(size_t size, size_t align) { return pcpu_alloc(size, align, true); } @@ -1267,7 +1269,7 @@ static void pcpu_reclaim(struct work_struct *work) * CONTEXT: * Can be called from atomic context. */ -void free_percpu(void *ptr) +void free_percpu(void __percpu *ptr) { void *addr; struct pcpu_chunk *chunk; -- cgit v1.2.3