[PATCH 0/2] Configurable max discard size

From	Jens Axboe <axboe@fb.com>
Newsgroups	linux.kernel
Subject	[PATCH 0/2] Configurable max discard size
Date	2015-07-14 17:10 +0200
Message-ID	<pMa0h-3Rk-7@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

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Hi,

Most drivers use UINT_MAX (or some variant thereof) for max discard
size, since they don't have a real limit for a non-data transferring
command. This is fine from a throughput point of view, but for a lot
of devices (all?), it truly sucks on latency. We've seen cases of
hundreds of msec in latencies for reads/writes when deleting files
on an fs with discard enabled. For the problematic devices that we
have tested, artificially limiting the size of the discards issued
brings it down to a more manageable 1-2ms max latencies.

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[PATCH 0/2] Configurable max discard size Jens Axboe <axboe@fb.com> - 2015-07-14 17:10 +0200
  Re: [PATCH 0/2] Configurable max discard size Christoph Hellwig <hch@lst.de> - 2015-07-14 18:10 +0200
    Re: [PATCH 0/2] Configurable max discard size Jens Axboe <axboe@fb.com> - 2015-07-14 18:10 +0200

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