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Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1pWaOg-00ECOz-2W; Mon, 27 Feb 2023 10:06:18 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id A536330030B; Mon, 27 Feb 2023 11:06:16 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 8E429209F7545; Mon, 27 Feb 2023 11:06:16 +0100 (CET) Date: Mon, 27 Feb 2023 11:06:16 +0100 From: Peter Zijlstra To: Raghavendra K T Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Ingo Molnar , Mel Gorman , Andrew Morton , David Hildenbrand , rppt@kernel.org, Bharata B Rao , Disha Talreja Subject: Re: [PATCH V2 2/3] sched/numa: Enhance vma scanning logic Message-ID: References: <5f0872657ddb164aa047a2231f8dc1086fe6adf6.1675159422.git.raghavendra.kt@amd.com> <048964e8-179f-de7b-1190-831779d9911f@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 26704C0003 X-Stat-Signature: 5jbykj5rrcpdh9i6dr8o5e9qm3nue8pi X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1677492391-943605 X-HE-Meta: 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 s5y8XDaf WUxPNq7tZVgLBtz1qHuJL1AiriABN6fegF//IAO4fTqhGYEOqOyJq9km8PgokOQu9VmfxEefdG8lDjYA+1ET+5k3UYeCqxdXzIH5P4cRBDRPbNMYSe6W/64eD9ZMbMHgHCl5EL2RMG4PGNmOfRTxyFv82jg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Feb 27, 2023 at 12:10:41PM +0530, Raghavendra K T wrote: > In summary: I do see that access to VMAs from disjoint sets is not fully > fair, But on the other hand it is not very bad too. There is definitely > some scope or possibility to explore/improve fairness in this area > further. Ok, might be good to summarize some of this in a comment near here, so that readers are aware of the caveat of this code. > PS: I have also tested above applying V3 patch (which incorporates your > suggestions), have not seen much deviation in observation with patch. I'll see if I can find it in this dumpester fire I call inbox :-)