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From: Andrew Morton <akpm@linux-foundation.org>
To: vitaly.wool@konsulko.com
Cc: linux-mm@kvack.org, ddstreet@ieee.org
Subject: Re: [PATCH] zswap: add allocation hysteresis if pool limit is hit
Date: Tue, 31 Dec 2019 14:57:02 -0800	[thread overview]
Message-ID: <20191231145702.69b5d7ed73d4b29a3679ebeb@linux-foundation.org> (raw)
In-Reply-To: <20191225203730.4632-1-vitaly.wool@konsulko.com>

On Wed, 25 Dec 2019 22:37:30 +0200 vitaly.wool@konsulko.com wrote:

> From: Vitaly Wool <vitaly.wool@konsulko.com>
> 
> zswap will always try to shrink pool when zswap is full. If there
> is a high pressure on zswap it will result in flipping pages in
> and out zswap pool without any real benefit, and the overall system
> performance will drop. The previous discussion on this subject [1]
> ended up with a suggestion to implement a sort of hysteresis to
> refuse taking pages into zswap pool until it has sufficient space
> if the limit has been hit. This is my take on this.
> 
> Hysteresis is controlled with a sysfs-configurable parameter
> 'accept_threhsold_percent'. It specifies the threshold at which
> zswap would start accepting pages again after it became full.

Please let's give the full path to the sysfs file.

Can we please include an update to the documentation? 
Documentation/vm/zswap.rst, I assume.




      reply	other threads:[~2019-12-31 22:57 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-25 20:37 vitaly.wool
2019-12-31 22:57 ` Andrew Morton [this message]

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