Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
1 年多 前同步成功

通知 160
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 10 3月, 2011 2 次提交
    • J
      perf top: Don't let events to eat up whole header line · 65472503
      由 Jiri Olsa 提交于 
      Passing multiple events might force out information about pid/tid/cpu.
Attached patch leaves 30 characters for this info at the expense of the
events' names.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Han Pingtian <phan@redhat.com>
LKML-Reference: <1299528821-17521-3-git-send-email-jolsa@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      65472503
    • J
      perf top: Fix events overflow in top command · b9a46bba
      由 Jiri Olsa 提交于 
      The snprintf function returns number of printed characters even if it
cross the size parameter. So passing enough events via '-e' parameter
will cause segmentation fault.

It's reproduced by following command:

perf top -e `perf list | grep Tracepoint | awk -F'[' '\
{gsub(/[[:space:]]+/,"",$1);array[FNR]=$1}END{outputs=array[1];\
for (i=2;i<=FNR;i++){ outputs=outputs "," array[i];};print outputs}'`

Attached patch is adding SNPRINTF macro that provides the overflow check
and returns actuall number of printed characters.
Reported-by: NHan Pingtian <phan@redhat.com>
Cc: Han Pingtian <phan@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1299528821-17521-2-git-send-email-jolsa@redhat.com>
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b9a46bba
  3. 09 3月, 2011 3 次提交
    • J
      kprobes: Disabling optimized kprobes for entry text section · 2a8247a2
      由 Jiri Olsa 提交于 
      You can crash the kernel (with root/admin privileges) using kprobe tracer by running:

 echo "p system_call_after_swapgs" > ./kprobe_events
 echo 1 > ./events/kprobes/enable

The reason is that at the system_call_after_swapgs label, the
kernel stack is not set up. If optimized kprobes are enabled,
the user space stack is being used in this case (see optimized
kprobe template) and this might result in a crash.

There are several places like this over the entry code
(entry_$BIT). As it seems there's no any reasonable/maintainable
way to disable only those places where the stack is not ready, I
switched off the whole entry code from kprobe optimizing.
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: acme@redhat.com
Cc: fweisbec@gmail.com
Cc: ananth@in.ibm.com
Cc: davem@davemloft.net
Cc: a.p.zijlstra@chello.nl
Cc: eric.dumazet@gmail.com
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <1298298313-5980-3-git-send-email-jolsa@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2a8247a2
    • J
      x86: Separate out entry text section · ea714547
      由 Jiri Olsa 提交于 
      Put x86 entry code into a separate link section: .entry.text.

Separating the entry text section seems to have performance
benefits - caused by more efficient instruction cache usage.

Running hackbench with perf stat --repeat showed that the change
compresses the icache footprint. The icache load miss rate went
down by about 15%:

 before patch:
         19417627  L1-icache-load-misses      ( +-   0.147% )

 after patch:
         16490788  L1-icache-load-misses      ( +-   0.180% )

The motivation of the patch was to fix a particular kprobes
bug that relates to the entry text section, the performance
advantage was discovered accidentally.

Whole perf output follows:

 - results for current tip tree:

  Performance counter stats for './hackbench/hackbench 10' (500 runs):

         19417627  L1-icache-load-misses      ( +-   0.147% )
       2676914223  instructions             #      0.497 IPC     ( +- 0.079% )
       5389516026  cycles                     ( +-   0.144% )

      0.206267711  seconds time elapsed   ( +-   0.138% )

 - results for current tip tree with the patch applied:

  Performance counter stats for './hackbench/hackbench 10' (500 runs):

         16490788  L1-icache-load-misses      ( +-   0.180% )
       2717734941  instructions             #      0.502 IPC     ( +- 0.079% )
       5414756975  cycles                     ( +-   0.148% )

      0.206747566  seconds time elapsed   ( +-   0.137% )
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: masami.hiramatsu.pt@hitachi.com
Cc: ananth@in.ibm.com
Cc: davem@davemloft.net
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20110307181039.GB15197@jolsa.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      ea714547
    • I
      Merge commit 'v2.6.38-rc8' into perf/core · 86cb2ec7
      由 Ingo Molnar 提交于 
      Merge reason: Merge latest fixes.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      86cb2ec7
  5. 08 3月, 2011 12 次提交
  7. 07 3月, 2011 8 次提交
  9. 06 3月, 2011 6 次提交
  11. 05 3月, 2011 9 次提交