diff options
| author | Vineet Gupta <vgupta@synopsys.com> | 2016-09-19 16:42:25 -0700 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2016-09-30 14:48:22 -0700 |
| commit | 86effd0dc675c36caed7b954d7f4f63b77c353b5 (patch) | |
| tree | 618b2e5e1bed7286aead4cb7c4fe83157bdb583c /arch/arc/kernel | |
| parent | 5a205a32ffccf6e720a2d2b3aee44b16619016a6 (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.S | 3 |
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) |