From: Matthew Wilcox <willy@infradead.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-block@vger.kernel.org, clm@fb.com,
torvalds@linux-foundation.org, david@fromorbit.com
Subject: Re: [PATCH 1/6] fs: add read support for RWF_UNCACHED
Date: Tue, 17 Dec 2019 07:57:49 -0800 [thread overview]
Message-ID: <20191217155749.GC32169@bombadil.infradead.org> (raw)
In-Reply-To: <20191217143948.26380-2-axboe@kernel.dk>
On Tue, Dec 17, 2019 at 07:39:43AM -0700, Jens Axboe wrote:
> +static void buffered_put_page(struct page *page, bool clear_mapping)
> +{
> + if (clear_mapping)
> + page->mapping = NULL;
> + put_page(page);
> +}
I'm not a huge fan of the variable name 'clear_mapping'. It describes
what it does rather than why it does it. So maybe 'drop_immediate'?
Or 'uncached'?
> if (!page) {
> if (iocb->ki_flags & IOCB_NOWAIT)
> goto would_block;
> + /* UNCACHED implies no read-ahead */
> + if (iocb->ki_flags & IOCB_UNCACHED) {
> + did_dio_begin = true;
> + /* block truncate for UNCACHED reads */
> + inode_dio_begin(inode);
I think this needs to be:
if (!did_dio_begin)
inode_dio_begin(inode);
did_dio_begin = true;
otherwise inode->i_dio_count is going to be increased once per uncached
page. Do you have a test in your test-suite that does I/O to more than
one page at a time?
next prev parent reply other threads:[~2019-12-17 15:57 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-17 14:39 [PATCHSET v5 0/6] Support for RWF_UNCACHED Jens Axboe
2019-12-17 14:39 ` [PATCH 1/6] fs: add read support " Jens Axboe
2019-12-17 15:16 ` Guoqing Jiang
2019-12-17 16:42 ` Jens Axboe
2019-12-17 15:57 ` Matthew Wilcox [this message]
2019-12-17 16:41 ` Jens Axboe
2019-12-18 3:17 ` Dave Chinner
2019-12-17 14:39 ` [PATCH 2/6] mm: make generic_perform_write() take a struct kiocb Jens Axboe
2019-12-17 14:39 ` [PATCH 3/6] mm: make buffered writes work with RWF_UNCACHED Jens Axboe
2019-12-17 14:39 ` [PATCH 4/6] iomap: add struct iomap_ctx Jens Axboe
2019-12-17 19:39 ` Linus Torvalds
2019-12-17 20:26 ` Linus Torvalds
2019-12-18 0:15 ` Jens Axboe
2019-12-18 1:25 ` Darrick J. Wong
2019-12-17 14:39 ` [PATCH 5/6] iomap: support RWF_UNCACHED for buffered writes Jens Axboe
2019-12-18 1:52 ` Darrick J. Wong
2019-12-18 3:18 ` Jens Axboe
2019-12-18 4:15 ` Darrick J. Wong
2019-12-17 14:39 ` [PATCH 6/6] xfs: don't do delayed allocations for uncached " Jens Axboe
2019-12-18 1:57 ` Darrick J. Wong
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