linux-kernel - Re: [PATCH 07/19] perf script: Set up output options for in-stream attributes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 22 Oct 2013 10:35:30 +0300
From:	Adrian Hunter <adrian.hunter@...el.com>
To:	Arnaldo Carvalho de Melo <acme@...stprotocols.net>
CC:	David Ahern <dsahern@...il.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org,
	Frederic Weisbecker <fweisbec@...il.com>,
	Jiri Olsa <jolsa@...hat.com>, Mike Galbraith <efault@....de>,
	Namhyung Kim <namhyung@...il.com>,
	Paul Mackerras <paulus@...ba.org>,
	Stephane Eranian <eranian@...gle.com>
Subject: Re: [PATCH 07/19] perf script: Set up output options for in-stream
 attributes

On 18/10/13 17:32, Arnaldo Carvalho de Melo wrote:
> Em Fri, Oct 18, 2013 at 07:30:13AM -0600, David Ahern escreveu:
>> On 10/18/13 6:29 AM, Adrian Hunter wrote:
> 
>>> Attributes (struct perf_event_attr) are recorded separately in the perf.data
>>> file.  perf script uses them to set up output options.  However attributes
>>> can also be in the event stream, for example when the input is a pipe (i.e.
>>> live mode).  This patch makes perf script process in-stream attributes in
>>> the same way as on-file attributes.
>  
>> You have multiple changes in this patch -- expanding attribute
>> processing to set output options per the description above and you
>> are also making perf_script a stack variable. The latter should be a
>> separate patch.
> 
> Agreed, and this conversion of struct perf_script to be a stack variable is
> nice (killing globals, a favourite pastime, yeah!), I like it, but in the past
> one such conversion showed something nasty that made several people stare at
> the build seeing builtin-sched.o take ages to build...

Fixed in V2

> 
> Please consider testing before/after that specific stack move:
> 
> commit f36f83f947ede547833e462696893f866df77324
> Author: Namhyung Kim <namhyung.kim@....com>
> Date:   Tue Jun 4 14:46:19 2013 +0900
> 
>     perf sched: Move struct perf_sched definition out of cmd_sched()
>     
>     For some reason it consumed quite amount of compile time when declared
>     as local variable, and it disappeared when moved out of the function.
>     Moving other variables/tables didn't help.
>     
>     On my system this single-file-change build time reduced from 11s to 3s.
> 
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/