From: Christoph Hellwig <hch@infradead.org>
To: Matthew Wilcox <willy@infradead.org>
Cc: Shyam Prasad N <nspmangalore@gmail.com>,
David Howells <dhowells@redhat.com>,
Steve French <smfrench@gmail.com>,
CIFS <linux-cifs@vger.kernel.org>
Subject: Re: Classification of reads within a filesystem
Date: Thu, 22 Jul 2021 05:14:20 +0100 [thread overview]
Message-ID: <YPjwnHOFkKFKovI4@infradead.org> (raw)
In-Reply-To: <YPhexTyuuE0/Wxf5@casper.infradead.org>
On Wed, Jul 21, 2021 at 06:52:05PM +0100, Matthew Wilcox wrote:
> Oh ... except for swap. For NFS only, it calls ->readpage, so it really
> wants ->readpage to be async so it can kick off multiple pages and
> then wait for the one it actually needs. That gets into a conversation
> about how much we really care about swap-over-NFS, whether swap should
> be using ->readpage or ->direct_IO, and whether swap should use the
> file readahead code or its own virtual address based readahead code.
> Most of those discussions are outside my area of expertise.
It really should be using direct I/O. I think one issue back in the
day was the odd locking requirements for swap, but that's something we
could overcome.
next prev parent reply other threads:[~2021-07-22 4:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-21 17:08 Classification of reads within a filesystem Shyam Prasad N
2021-07-21 17:52 ` Matthew Wilcox
2021-07-22 4:14 ` Christoph Hellwig [this message]
2021-07-23 10:37 ` Shyam Prasad N
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