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authorVineet Gupta <vgupta@synopsys.com>2016-09-19 16:42:25 -0700
committerVineet Gupta <vgupta@synopsys.com>2016-09-30 14:48:22 -0700
commit86effd0dc675c36caed7b954d7f4f63b77c353b5 (patch)
tree618b2e5e1bed7286aead4cb7c4fe83157bdb583c /arch/arc/kernel
parent5a205a32ffccf6e720a2d2b3aee44b16619016a6 (diff)
ARC: dw2 unwind: enable cfi pseudo ops in string lib
This uses a new set of annoations viz. ENTRY_CFI/END_CFI to enabel cfi ops generation. Note that we didn't change the normal ENTRY/EXIT as we don't actually want unwind info in the trap/exception/interrutp handlers which use these, as unwinder then gets confused (it keeps recursing vs. stopping). Semantically these are leaf routines and unwinding should stop when it hits those routines. Before ------ 28.52% 1.19% 9929 hackbench libuClibc-1.0.17.so [.] __write_nocancel | ---__write_nocancel |--8.95%--EV_Trap | --8.25%--sys_write | |--3.93%--sock_write_iter ... |--2.62%--memset <==== [LEAF entry as no unwind info] ^^^^^^ After ----- 29.46% 1.24% 13622 hackbench libuClibc-1.0.17.so [.] __write_nocancel | ---__write_nocancel |--9.31%--EV_Trap | --8.62%--sys_write | |--4.17%--sock_write_iter ... |--6.19%--sys_write | --6.19%--sock_write_iter | unix_stream_sendmsg | |--1.62%--sock_alloc_send_pskb | |--0.89%--sock_def_readable | |--0.88%--_raw_spin_unlock_irqrestore | |--0.69%--memset | | ^^^^^^ <==== [now in proper callframe] | | | --0.52%--skb_copy_datagram_from_iter Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/kernel')
-rw-r--r--arch/arc/kernel/ctx_sw_asm.S3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arc/kernel/ctx_sw_asm.S b/arch/arc/kernel/ctx_sw_asm.S
index e6890b1f8650..7c1f365ef3d2 100644
--- a/arch/arc/kernel/ctx_sw_asm.S
+++ b/arch/arc/kernel/ctx_sw_asm.S
@@ -23,6 +23,7 @@
.global __switch_to
.type __switch_to, @function
__switch_to:
+ CFI_STARTPROC
/* Save regs on kernel mode stack of task */
st.a blink, [sp, -4]
@@ -59,4 +60,4 @@ __switch_to:
ld.ab blink, [sp, 4]
j [blink]
-END(__switch_to)
+END_CFI(__switch_to)