From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
To: Matthew Wilcox <willy@infradead.org>
Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
Michal Hocko <mhocko@suse.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Johannes Weiner <hannes@cmpxchg.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Roman Gushchin <guro@fb.com>
Subject: Re: [PATCH RFC] fs/fcntl: add fcntl F_GET_RSS
Date: Mon, 28 Oct 2019 14:20:51 +0300 [thread overview]
Message-ID: <33978ec2-ac27-1b8b-ba33-3bd2c66aa016@yandex-team.ru> (raw)
In-Reply-To: <20191028111034.GS2963@bombadil.infradead.org>
On 28/10/2019 14.10, Matthew Wilcox wrote:
> On Mon, Oct 28, 2019 at 01:28:09PM +0300, Konstantin Khlebnikov wrote:
>> + if (dax_mapping(mapping))
>> + pages = READ_ONCE(mapping->nrexceptional);
>> + else
>> + pages = READ_ONCE(mapping->nrpages);
>
> I'm not sure this is the right calculation for DAX files. We haven't
> allocated any memory for DAX; we're just accessing storage directly.
> The entries in the page caache are just translation from file offset to
> physical address.
>
Yep, makes sense. If RSS declared as memory usage then this chunk must do
pages = READ_ONCE(mapping->nrpages) unconditionally and report 0 for DAX.
next prev parent reply other threads:[~2019-10-28 11:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-28 10:28 [PATCH RFC] fs/fcntl: add fcntl F_GET_RSS Konstantin Khlebnikov
2019-10-28 11:10 ` Matthew Wilcox
2019-10-28 11:20 ` Konstantin Khlebnikov [this message]
2019-10-28 11:46 ` Florian Weimer
2019-10-28 12:55 ` Konstantin Khlebnikov
2019-10-28 13:05 ` Florian Weimer
2019-10-28 12:27 ` Linus Torvalds
2019-10-28 12:49 ` Konstantin Khlebnikov
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