From: Andrew Morton <akpm@linux-foundation.org>
To: Shaohua Li <shli@kernel.org>
Cc: linux-mm@kvack.org, riel@redhat.com, minchan@kernel.org,
kmpark@infradead.org, hughd@google.com, aquini@redhat.com
Subject: Re: [patch 1/4 v4]swap: change block allocation algorithm for SSD
Date: Wed, 12 Jun 2013 15:21:03 -0700 [thread overview]
Message-ID: <20130612152103.e929320315c4bf9d82fe33d5@linux-foundation.org> (raw)
In-Reply-To: <20130326053706.GA19646@kernel.org>
On Tue, 26 Mar 2013 13:37:06 +0800 Shaohua Li <shli@kernel.org> wrote:
> I'm using a fast SSD to do swap. scan_swap_map() sometimes uses up to 20~30%
> CPU time (when cluster is hard to find, the CPU time can be up to 80%), which
> becomes a bottleneck. scan_swap_map() scans a byte array to search a 256 page
> cluster, which is very slow.
>
> Here I introduced a simple algorithm to search cluster.
I had a few comments on the patches.
Problem is, I'm still stuck on
http://ozlabs.org/~akpm/mmots/broken-out/swap-add-a-simple-detector-for-inappropriate-swapin-readahead-fix.patch.
I quite dislike that patch - it has to have more magic handwavy
constants per square inch than any patch I've ever seen before.
I'd really prefer that we come up with something more robust, adaptive
and generally thought-through than this.
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next prev parent reply other threads:[~2013-06-12 22:21 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-26 5:37 [patch 1/4 v4]swap: change block allocation algorithm for SSD Shaohua Li
2013-03-29 2:00 ` Rafael Aquini
2013-03-29 2:50 ` Shaohua Li
2013-03-29 3:13 ` Rafael Aquini
2013-04-29 22:17 ` Rafael Aquini
2013-06-12 22:21 ` Andrew Morton [this message]
2013-06-12 22:21 ` Andrew Morton
2013-06-13 10:54 ` Shaohua Li
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