From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B3B7C47082 for ; Mon, 7 Jun 2021 23:52:45 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 1FDF061182 for ; Mon, 7 Jun 2021 23:52:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1FDF061182 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A53D76B0036; Mon, 7 Jun 2021 19:52:44 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9DCC66B006E; Mon, 7 Jun 2021 19:52:44 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 856586B0070; Mon, 7 Jun 2021 19:52:44 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0004.hostedemail.com [216.40.44.4]) by kanga.kvack.org (Postfix) with ESMTP id 4EF2F6B0036 for ; Mon, 7 Jun 2021 19:52:44 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id D3CE6181AEF0B for ; Mon, 7 Jun 2021 23:52:43 +0000 (UTC) X-FDA: 78228580206.02.5720331 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf05.hostedemail.com (Postfix) with ESMTP id 217F5E000240 for ; Mon, 7 Jun 2021 23:52:40 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 59258610E7; Mon, 7 Jun 2021 23:52:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1623109962; bh=gZ7ag71htLxjG6QOcoLqIDfNOCltH8Ce826lm+nq7yM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=O3jUTkfKWL4/blrQFYIsKvIZXWutsz+IbZFBx+OVxX9C2UQpizZpg4Mf4DQHbaXj8 8cqwH3XTcwDDzYwhWy9hqH54zSYylz7VJJe6W4x1eGUyFYf47lIimqT0I17baYB21n nyCuxTJPuapCk7QNLUVbTOyDs2dwXq0vw1HBGbGQ= Date: Mon, 7 Jun 2021 16:52:41 -0700 From: Andrew Morton To: Nicholas Piggin Cc: Randy Dunlap , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org, Anton Blanchard , Andy Lutomirski Subject: Re: [PATCH v4 4/4] powerpc/64s: enable MMU_LAZY_TLB_SHOOTDOWN Message-Id: <20210607165241.4dcd4cf63f96437c5650d179@linux-foundation.org> In-Reply-To: <20210605014216.446867-5-npiggin@gmail.com> References: <20210605014216.446867-1-npiggin@gmail.com> <20210605014216.446867-5-npiggin@gmail.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=O3jUTkfK; spf=pass (imf05.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 217F5E000240 X-Stat-Signature: kbtmymg1gitkzcyp9xyqr1e6gm6wfm8g X-HE-Tag: 1623109960-907972 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 Sat, 5 Jun 2021 11:42:16 +1000 Nicholas Piggin wrote: > On a 16-socket 192-core POWER8 system, a context switching benchmark > with as many software threads as CPUs (so each switch will go in and > out of idle), upstream can achieve a rate of about 1 million context > switches per second. After this patch it goes up to 118 million. Nice. Do we have a feel for the benefit on any real-world workloads? Could any other architectures benefit from these changes?