From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] mm/shrinker: make unregister_shrinker() less fragile
Date: Mon, 13 Jul 2015 18:34:42 +0900 [thread overview]
Message-ID: <20150713092531.GA578@swordfish> (raw)
In-Reply-To: <20150713090358.GA28901@infradead.org>
On (07/13/15 02:03), Christoph Hellwig wrote:
> On Mon, Jul 13, 2015 at 03:52:53PM +0900, Sergey Senozhatsky wrote:
> > Why? In some sense, shrinker callbacks are just a way to be nice.
> > No one writes a driver just to be able to handle shrinker calls. An
> > ability to react to those calls is just additional option; it does
> > not directly affect or limit driver's functionality (at least, it
> > really should not).
>
> No, they are not just nice. They are a fundamental part of memory
> management and required to reclaim (often large) amounts of memory.
Yes. 'Nice' used in a sense that drivers have logic to release the
memory anyway; mm asks volunteers (the drivers that have registered
shrinker callbacks) to release some spare/wasted/etc. when things
are getting tough (the drivers are not aware of that in general).
This is surely important to mm, not to the driver though -- it just
agrees to be 'nice', but even not expected to release any memory at
all (IOW, this is not a contract).
-ss
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next prev parent reply other threads:[~2015-07-13 9:34 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-11 2:51 Sergey Senozhatsky
2015-07-11 2:51 ` [PATCH 1/2] mm/shrinker: do not NULL dereference uninitialized shrinker Sergey Senozhatsky
2015-07-11 2:51 ` [PATCH 2/2] mm/shrinker: add init_shrinker() function Sergey Senozhatsky
2015-07-11 10:02 ` [PATCH 0/2] mm/shrinker: make unregister_shrinker() less fragile Christoph Hellwig
2015-07-12 2:47 ` Sergey Senozhatsky
2015-07-13 6:33 ` Christoph Hellwig
2015-07-13 6:52 ` Sergey Senozhatsky
2015-07-13 9:03 ` Christoph Hellwig
2015-07-13 9:34 ` Sergey Senozhatsky [this message]
2015-07-14 7:17 ` Christoph Hellwig
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