linux-kernel - Re: [PATCH 1/6] tracing, page-allocator: Add trace events for page allocation and page freeing

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:	Sat, 8 Aug 2009 14:47:13 +0900
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	Mel Gorman <mel@....ul.ie>
Cc:	Larry Woodman <lwoodman@...hat.com>, Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>, riel@...hat.com,
	Peter Zijlstra <peterz@...radead.org>,
	LKML <linux-kernel@...r.kernel.org>, linux-mm@...ck.org
Subject: Re: [PATCH 1/6] tracing, page-allocator: Add trace events for page 
	allocation and page freeing

2009/8/8 Mel Gorman <mel@....ul.ie>:
> This patch adds trace events for the allocation and freeing of pages,
> including the freeing of pagevecs.  Using the events, it will be known what
> struct page and pfns are being allocated and freed and what the call site
> was in many cases.
>
> The page alloc tracepoints be used as an indicator as to whether the workload
> was heavily dependant on the page allocator or not. You can make a guess based
> on vmstat but you can't get a per-process breakdown. Depending on the call
> path, the call_site for page allocation may be __get_free_pages() instead
> of a useful callsite. Instead of passing down a return address similar to
> slab debugging, the user should enable the stacktrace and seg-addr options
> to get a proper stack trace.
>
> The pagevec free tracepoint has a different usecase. It can be used to get
> a idea of how many pages are being dumped off the LRU and whether it is
> kswapd doing the work or a process doing direct reclaim.
>
> Signed-off-by: Mel Gorman <mel@....ul.ie>
> Acked-by: Rik van Riel <riel@...hat.com>

Looks good to me.
  Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
--
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/