From: Jeff Moyer <jmoyer@redhat.com>
To: 韩磊 <bonben1989@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: About read/write requests in IO scheduler
Date: Mon, 11 Nov 2013 13:32:24 -0500 [thread overview]
Message-ID: <x498uwuhjrb.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <CAK2Ky6wEUDS0bQbbYSKv+hX=f6sCjJM7Fu4zOzAR_ftVX1obUg@mail.gmail.com> ("韩磊"'s message of "Sun, 10 Nov 2013 20:36:10 +0800")
韩磊 <bonben1989@gmail.com> writes:
> In IO scheduler level, whether all the read requests are synchronous?
Generically, yes, I/O schedulers (and the whole block layer, in fact)
consider READs synchronous:
/*
* We regard a request as sync, if either a read or a sync write
*/
static inline bool rw_is_sync(unsigned int rw_flags)
{
return !(rw_flags & REQ_WRITE) || (rw_flags & REQ_SYNC);
}
next prev parent reply other threads:[~2013-11-11 18:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-10 12:36 About read/write requests in IO scheduler 韩磊
2013-11-11 13:21 ` Fwd: " 韩磊
2013-11-11 18:32 ` Jeff Moyer [this message]
2013-11-12 2:51 ` 韩磊
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