From: Mike Galbraith <efault@gmx.de>
To: "J. Bruce Fields" <bfields@fieldses.org>
Cc: lkml <linux-kernel@vger.kernel.org>,
Jeff Layton <jlayton@kernel.org>,
linux-nfs@vger.kernel.org
Subject: Re: NFS: 82ms wakeup latency 4.14-rc4
Date: Mon, 18 Dec 2017 19:34:50 +0100 [thread overview]
Message-ID: <1513622090.7113.66.camel@gmx.de> (raw)
In-Reply-To: <20171218172711.GA12454@fieldses.org>
On Mon, 2017-12-18 at 12:27 -0500, J. Bruce Fields wrote:
> I'd forgotten about throughput/latency tradeoffs--but
> couldn't those in theory be managed by runtime configuration of the
> sceduler, or at least some smaller hammer than turning off preemption
> entirely?
A kernel that has all of the goop required to support preemption can't
possibly perform as well as a kernel that can simply assume everything
is safe. All that infrastructure costs cycles.
-Mike
next prev parent reply other threads:[~2017-12-18 18:35 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-18 15:17 NFS: 82ms wakeup latency 4.14-rc4 Mike Galbraith
2017-12-18 15:31 ` Mike Galbraith
2017-12-18 16:35 ` J. Bruce Fields
2017-12-18 16:48 ` Mike Galbraith
2017-12-18 17:00 ` Mike Galbraith
2017-12-18 17:17 ` Mike Galbraith
2017-12-18 17:27 ` J. Bruce Fields
2017-12-18 17:47 ` Mike Galbraith
2017-12-18 18:34 ` Mike Galbraith [this message]
2017-12-18 17:24 ` Trond Myklebust
2017-12-18 17:24 ` Trond Myklebust
2017-12-18 17:26 ` Mike Galbraith
2018-01-02 20:29 ` [patch] fs/nfs: Add a resched point to nfs_commit_release_pages() Mike Galbraith
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