On 04/21/11 12:48, Francis Moreau wrote: > On Thu, Apr 21, 2011 at 5:23 PM, David Ahern <[email protected]> wrote: >> >> >> On 04/21/11 01:46, Francis Moreau wrote: >>> Hello, >>> >>> Sorry if the question is dumb but I'm a bit lost about this. >>> >>> I know that ftrace exists but I think that perf can do this too: I >>> have a userspace application which is calling a libc C function (read) >>> which ends up doing a sys_read. >>> >>> For the sys_read, I'd like to see what's happening in the kernel by >>> displaying the call graph. >>> >>> Can perf do that ? >> >> Have you tried 'perf record -g'? >> > > Well, I don't see how it can be done with perf record -g. > > Let's say I'm interested to see the path taken in the kernel when a > process is calling sys_sleep: > > $ perf record -g sleep 1 > > Then I can use: > > $ perf report -g > > But I don't see what I am asking for. > > What am I missing ?
You want the individual samples? if so, perf script dumps them and you can see the callchain for each sys_read. David > > Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
