Messages in this thread |  | | | Date | Thu, 20 May 2010 06:41:50 -0700 | | From | "H. Peter Anvin" <> | | Subject | Re: [tip:perf/core] perf: Use read() instead of lseek() in trace_event_read.c:skip() |
| |
On 05/20/2010 06:39 AM, Pekka Enberg wrote: > On Thu, May 20, 2010 at 3:54 PM, tip-bot for Tom Zanussi > <tzanussi@gmail.com> wrote: >> Commit-ID: cbb5cf7ff6b298beacfe23db3386335b0b9c0a2d >> Gitweb: http://git.kernel.org/tip/cbb5cf7ff6b298beacfe23db3386335b0b9c0a2d >> Author: Tom Zanussi <tzanussi@gmail.com> >> AuthorDate: Tue, 4 May 2010 23:02:10 -0500 >> Committer: Frederic Weisbecker <fweisbec@gmail.com> >> CommitDate: Thu, 20 May 2010 08:37:17 +0200 >> >> perf: Use read() instead of lseek() in trace_event_read.c:skip() >> >> This is a small fix for a problem affecting live-mode, introduced >> recently: >> >> root@tropicana:~# perf trace rwtop >> perf trace started with Perl >> script /root/libexec/perf-core/scripts/perl/rwtop.pl >> >> Fatal: did not read header event >> >> commit d00a47cce569a3e660a8c9de5d57af28d6a9f0f7 added a skip() >> function to skip over e.g. header_page, but this doesn't work for >> live mode. This patch re-implements skip() to use read() instead of >> lseek() to fix that. > > Out of curiosity: why doesn't lseek() work and why can't we fix that?
Presumably because we're reading from a nonseekable stream?
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
|  |