From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: Re: timing information with perf Date: Fri, 13 Nov 2015 16:47:26 -0300 Message-ID: <20151113194726.GN7160@kernel.org> References: <94D0C06D-C3A7-4BD1-9898-124EE0AA923D@netapp.com> <20151112215728.GD7160@kernel.org> <21ECAC65-E51A-4430-A499-FFE216BF856B@netapp.com> <20151112233429.GG7160@kernel.org> <5B1B04DE-98CC-44CC-BC75-896C2F029799@netapp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mail.kernel.org ([198.145.29.136]:38548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754225AbbKMTrb (ORCPT ); Fri, 13 Nov 2015 14:47:31 -0500 Content-Disposition: inline In-Reply-To: <5B1B04DE-98CC-44CC-BC75-896C2F029799@netapp.com> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: "Kornievskaia, Olga" Cc: "linux-perf-users@vger.kernel.org" Em Fri, Nov 13, 2015 at 05:01:57PM +0000, Kornievskaia, Olga escreveu: > > On Nov 12, 2015, at 6:34 PM, Arnaldo Carvalho de Melo wrote: > > There is also: > >=20 > > 11.033 ( ): nfs:nfs_fsync_enter:fileid=3D00:26:2360376 f= handle=3D0xfd52be06 version=3D6216410999163535246 ) > > 15.535 ( ): nfs:nfs_fsync_exit:error=3D0 fileid=3D00:26:= 2360376 fhandle=3D0xfd52be06 type=3D8 (REG) version=3D62164109991695351= 49 size=3D1576 cache_validity=3D25 (INVALID_ATTR|INVALID_ACCESS|INVALID= _ACL) nfs_flags=3D4 ()) > >=20 > > Well, you also can just get these and do some scripting, no, in thi= s case: > >=20 > > 15.535 - 11.033 =3D 4.502ms > >=20 > > for that nfs_fsync :-) > David and Arnaldo thank you your replies. I can see that to acquire > the timings for non-syscall events requires scripting. Would I be > missing something by not using =E2=80=9Cperf=E2=80=9D and instead doi= ng scripting on > the output that I get from the trace_pipe? I guess instead of the Both will present you with the timestamp and parameters for the enabled tracepoints, so I think that at this state, yes, you will not get anything better from perf than what you'll get from ftrace via debugfs. But this comes from time to time, the logic used for raw_syscalls:sys_enter -> raw_syscalls:sys_exit, using some set of keys to match one to the other should be extended to be used with non-syscal= l events, such as the ones you mention here. i.e. whereas raw_syscalls:sys_exit has a "ret" variable to tell the result of the sys_enter+sys_exit operation, nfs_fsync_exit has "error", I guess, for the same purpose :) - Arnaldo