linux-kernel - Re: [PATCH 4/4] tracing, page-allocator: Add a postprocessing script for page-allocator-related ftrace events

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]

Message-Id: <20090804135315.b2678e11.akpm@linux-foundation.org>
Date:	Tue, 4 Aug 2009 13:53:15 -0700
From:	Andrew Morton <akpm@...ux-foundation.org>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	penberg@...helsinki.fi, a.p.zijlstra@...llo.nl, fweisbec@...il.com,
	rostedt@...dmis.org, mel@....ul.ie, lwoodman@...hat.com,
	riel@...hat.com, peterz@...radead.org,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH 4/4] tracing, page-allocator: Add a postprocessing
 script for page-allocator-related ftrace events

On Tue, 4 Aug 2009 22:35:26 +0200
Ingo Molnar <mingo@...e.hu> wrote:

> Did you never want to see whether firefox is leaking [any sort of] 
> memory, and if yes, on what callsites? Try something like on an 
> already running firefox context:
> 
>   perf stat -e kmem:mm_page_alloc \
>             -e kmem:mm_pagevec_free \
>             -e kmem:mm_page_free_direct \
>      -p $(pidof firefox-bin) sleep 10
> 
> ... and "perf record" for the specific callsites.

OK, that would be useful.  What does the output look like?

In what way is it superior to existing ways of finding leaks?

> this perf stuff is immensely flexible and a very unixish 
> abstraction. The perf.data contains timestamped trace entries of 
> page allocations and freeing done.
> 
> [...]
> > It would be nice to at least partially remove the vmstat/meminfo 
> > infrastructure but I don't think we can do that?
> 
> at least meminfo is an ABI for sure - vmstat too really.
> 
> But we can stop adding new fields into obsolete, inflexible and 
> clearly deficient interfaces, and we can standardize new 
> instrumentation to use modern instrumentation facilities - i.e. 
> tracepoints and perfcounters.

That's bad.  Is there really no way in which we can consolidate _any_
of that infrastructure?  We just pile in new stuff alongside the old?

The worst part is needing two unrelated sets of userspace tools to
access basically-identical things.


--
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/