linux-kernel - Re: [v5][PATCH 6/6] mm: vmscan: drain batch list during long operations

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: <20130604060553.GF14719@blaptop>
Date:	Tue, 4 Jun 2013 15:05:53 +0900
From:	Minchan Kim <minchan@...nel.org>
To:	Dave Hansen <dave@...1.net>
Cc:	linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	akpm@...ux-foundation.org, mgorman@...e.de,
	tim.c.chen@...ux.intel.com
Subject: Re: [v5][PATCH 6/6] mm: vmscan: drain batch list during long
 operations

On Mon, Jun 03, 2013 at 01:02:10PM -0700, Dave Hansen wrote:
> 
> From: Dave Hansen <dave.hansen@...ux.intel.com>
> 
> This was a suggestion from Mel:
> 
> 	http://lkml.kernel.org/r/20120914085634.GM11157@csn.ul.ie
> 
> Any pages we collect on 'batch_for_mapping_removal' will have
> their lock_page() held during the duration of their stay on the
> list.  If some other user is trying to get at them during this
> time, they might end up having to wait.
> 
> This ensures that we drain the batch if we are about to perform a
> pageout() or congestion_wait(), either of which will take some
> time.  We expect this to help mitigate the worst of the latency
> increase that the batching could cause.

Nice idea but I could see drain before pageout but congestion_wait?

-- 
Kind regards,
Minchan Kim
--
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/