linux-kernel - Re: [PATCH] migration: only migrate_prep() once per move

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.1.10.0904150840450.10217@qirst.com>
Date:	Wed, 15 Apr 2009 08:41:38 -0400 (EDT)
From:	Christoph Lameter <cl@...ux.com>
To:	Brice Goglin <Brice.Goglin@...ia.fr>
cc:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	linux-mm@...ck.org, LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] migration: only migrate_prep() once per move_pages()

On Wed, 15 Apr 2009, Brice Goglin wrote:

> But lru_add_drain_all() touches some code that I am far from
> understanding :/ Can we imagine using IPI instead of a deferred
> work_struct for this kind of things? Or maybe, for each processor, check
> whether drain_cpu_pagevecs() would have something to do before actually
> scheduling the local work_struct? It's racy, but migrate_prep() doesn't
> guarantee anyway that pages won't be moved out of the LRU before the
> actual migration, so...

IPI means that code must run with interrupts disabled.

> > BTW, current users of sys_move_pages() does retry when it gets -EBUSY ?
> >
>
> I'd say they ignore it since it doesn't happen often :)

Right.

--
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/