linux-kernel - Re: [PATCH RFC 3/3] slub: reparent memcg caches' slabs on memcg offline

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: <alpine.DEB.2.10.1405141119320.16512@gentwo.org>
Date:	Wed, 14 May 2014 11:20:51 -0500 (CDT)
From:	Christoph Lameter <cl@...ux.com>
To:	Vladimir Davydov <vdavydov@...allels.com>
cc:	hannes@...xchg.org, mhocko@...e.cz, akpm@...ux-foundation.org,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [PATCH RFC 3/3] slub: reparent memcg caches' slabs on memcg
 offline

On Tue, 13 May 2014, Vladimir Davydov wrote:

> Since the "slow" and the "normal" free's can't coexist at the same time,
> we must assure all conventional free's have finished before switching
> all further free's to the "slow" mode and starting reparenting. To
> achieve that, a percpu refcounter is used. It is taken and held during
> each "normal" free. The refcounter is killed on memcg offline, and the
> cache's pages migration is initiated from the refcounter's release
> function. If we fail to take a ref on kfree, it means all "normal"
> free's have been completed and the cache is being reparented right now,
> so we should free the object using the "slow" mode.

Argh adding more code to the free path touching more cachelines in the
process.

--
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/