From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [RFC PATCH for 4.18 00/14] Restartable Sequences Date: Wed, 2 May 2018 12:42:53 -0400 Message-ID: <20180502124253.145253cb@gandalf.local.home> References: <20180430224433.17407-1-mathieu.desnoyers@efficios.com> <660904075.9201.1525276988842.JavaMail.zimbra@efficios.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Daniel Colascione Cc: Mathieu Desnoyers , Peter Zijlstra , Paul McKenney , boqun.feng@gmail.com, luto@amacapital.net, davejwatson@fb.com, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Paul Turner , Andrew Morton , linux@arm.linux.org.uk, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, Andrew Hunter , andi@firstfloor.org, cl@linux.com, bmaurer@fb.com, josh@joshtriplett.org, torvalds@linux-foundation.org, catalin.marinas@arm.com, will.deacon@arm.com, Michael Kerrisk-manpages , Joel Fernandes List-Id: linux-api@vger.kernel.org On Wed, 02 May 2018 16:07:48 +0000 Daniel Colascione wrote: > Why couldn't we take a page fault just before schedule? The reason we can't > take a page fault in atomic context is that doing so might call schedule. > Here, we're about to call schedule _anyway_, so what harm does it do to > call something that might call schedule? If we schedule via that call, we > can skip the manual schedule we were going to perform. Another issue is slowing down something that is considered a fast path. -- Steve