From: Christoph Hellwig <hch@infradead.org>
To: Jan Kara <jack@suse.cz>
Cc: Sandeep Joshi <sanjos100@gmail.com>, linux-ext4@vger.kernel.org
Subject: Re: process hangs in ext4_sync_file
Date: Tue, 29 Oct 2013 10:04:35 -0700 [thread overview]
Message-ID: <20131029170435.GA7681@infradead.org> (raw)
In-Reply-To: <20131029144649.GB1890@quack.suse.cz>
On Tue, Oct 29, 2013 at 03:46:49PM +0100, Jan Kara wrote:
> No, it isn't really recommended for ordinary SSDs. If you have one of
> those fancy PCIe attached SSDs, 'discard' option might be useful for you
> but for usual SATA attached ones it's usually a disaster. There you might
> be better off running 'fstrim' command once a week or something like that.
While some early consumer SSDs were indeed pretty bad just by
theselves, and the lack of queue TRIM on most devices doesn't help,
these days the biggest blame is with Linux itself. Not only can't we
merge multiple requests into a single ranged TRIM, but we also execute
them all synchronously, meaning a constant stream of queue drains if
the discard option is used.
Once we've fixed those issue we can start blaming those vendors that
have issues again, but until that has happened we'd better shut up..
next prev parent reply other threads:[~2013-10-29 17:04 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-21 12:39 process hangs in ext4_sync_file Sandeep Joshi
2013-10-21 12:57 ` Zheng Liu
2013-10-22 3:24 ` Sandeep Joshi
2013-10-22 8:45 ` Sandeep Joshi
2013-10-23 10:20 ` Jan Kara
2013-10-23 14:58 ` Sandeep Joshi
2013-10-24 3:54 ` Zheng Liu
2013-10-29 5:36 ` Sandeep Joshi
[not found] ` <CAEfL3KmAXw+mE24kZkG4YHU3C98rU6pkbAwMhSO1pw1rg81HVw@mail.gmail.com>
2013-10-29 14:46 ` Jan Kara
2013-10-29 15:00 ` Sandeep Joshi
2013-10-29 15:26 ` Jan Kara
2013-10-29 17:04 ` Christoph Hellwig [this message]
2013-10-29 17:53 ` Jan Kara
2014-01-06 10:28 ` Sandeep Joshi
2014-01-06 14:32 ` Theodore Ts'o
2014-01-06 15:08 ` Sandeep Joshi
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