linux-kernel - Re: Sudden and massive page cache eviction

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:	Wed, 24 Nov 2010 09:32:09 -0800
From:	Dave Hansen <dave@...ux.vnet.ibm.com>
To:	Peter Schüller <scode@...tify.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org,
	Mattias de Zalenski <zalenski@...tify.com>,
	linux-mm@...ck.org
Subject: Re: Sudden and massive page cache eviction

On Wed, 2010-11-24 at 15:14 +0100, Peter Schüller wrote:
> >> Do you have any large page (hugetlbfs) or other multi-order (> 1 page)
> >> allocations happening in the kernel?
> 
> I forgot to address the second part of this question: How would I best
> inspect whether the kernel is doing that? 

I found out yesterday how to do it with tracing, but it's not a horribly
simple thing to do in any case.  You can watch the entries in slabinfo
and see if any of the ones with sizes over 4096 bytes are getting used
often.  You can also watch /proc/buddyinfo and see how often columns
other than the first couple are moving around.

Jumbo ethernet frames would be the most common reason to see these
allocations.  It's _probably_ not an issue in your case.

-- Dave

--
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/