Re: [PATCH -tip ] [BUGFIX] perf probe: Fix to probe on symbols withoptimization suffix
From: Arnaldo Carvalho de Melo
Date: Wed Sep 25 2013 - 11:38:48 EST
Em Wed, Sep 25, 2013 at 10:16:16PM +0900, Masami Hiramatsu escreveu:
> Fix perf probe to probe on some symbols which have some
> optimzation suffixes, e.g. ".part", ".isra", and ".constprop".
> To fix this issue, instead of using DIE name, perf probe
> uses symbol name found by dwfl_module_addrsym().
Thanks Masami! Now it behaves _exactly_ as I expected and need:
[root@zoo linux]# perf probe -L getname_flags:65
<getname_flags@/home/git/linux/fs/namei.c:65>
65 result->uptr = filename;
66 audit_getname(result);
return result;
error:
70 final_putname(result);
71 return err;
72 }
struct filename *
getname(const char __user * filename)
[root@zoo linux]# perf probe -V getname_flags:65
Available variables at getname_flags:65
@<getname_flags.part.35+178>
char* filename
int* empty
long int max
struct filename* result
[root@zoo linux]# perf probe 'getname_flags:66 pathname=result->name:string'
Added new event:
probe:getname_flags (on getname_flags:66 with pathname=result->name:string)
You can now use it in all perf tools, such as:
perf record -e probe:getname_flags -aR sleep 1
[root@zoo linux]# perf record -a -e probe:getname_flags
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.252 MB perf.data (~54692 samples) ]
[root@zoo linux]# perf script | grep -v '# | head -5
> ^C
[root@zoo linux]# perf script | grep -v '^#' | head -5
libvirtd 1163 [001] 100606.469450: probe:getname_flags: (ffffffff811a2f89) pathname="/proc/cpuinfo"
libvirtd 1163 [001] 100606.469563: probe:getname_flags: (ffffffff811a2f89) pathname="/sys/devices/system/node"
libvirtd 1163 [001] 100606.469596: probe:getname_flags: (ffffffff811a2f89) pathname="/sys/devices/system/node/node0"
libvirtd 1163 [001] 100606.469612: probe:getname_flags: (ffffffff811a2f89) pathname="/sys/devices/system/node/node0/cpu0/online"
libvirtd 1163 [001] 100606.469628: probe:getname_flags: (ffffffff811a2f89) pathname="/sys/devices/system/node/node0/cpu0/topology/physical_package_id"
[root@zoo linux]#
Thanks a lot, applied to my perf/urgent branch,
- Arnaldo
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