From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH 0/10] psi: pressure stall information for CPU, memory, and IO v2 Date: Thu, 12 Jul 2018 16:44:22 -0700 Message-ID: <20180712164422.a53cc0f9c26b078dbc7e5731@linux-foundation.org> References: <20180712172942.10094-1-hannes@cmpxchg.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180712172942.10094-1-hannes@cmpxchg.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Johannes Weiner Cc: Ingo Molnar , Peter Zijlstra , Linus Torvalds , Tejun Heo , Suren Baghdasaryan , Vinayak Menon , Christopher Lameter , Mike Galbraith , Shakeel Butt , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com On Thu, 12 Jul 2018 13:29:32 -0400 Johannes Weiner wrote: > > ... > > The io file is similar to memory. Because the block layer doesn't have > a concept of hardware contention right now (how much longer is my IO > request taking due to other tasks?), it reports CPU potential lost on > all IO delays, not just the potential lost due to competition. Probably dumb question: disks aren't the only form of IO. Does it make sense to accumulate PSI for other forms of IO? Networking comes to mind...