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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 80382C47094 for ; Mon, 7 Jun 2021 23:53:13 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E4B756108D for ; Mon, 7 Jun 2021 23:53:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E4B756108D 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=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4FzVYh10zpz3bsG for ; Tue, 8 Jun 2021 09:53:12 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=O3jUTkfK; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux-foundation.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=akpm@linux-foundation.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=O3jUTkfK; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4FzVY92chCz2yhd for ; Tue, 8 Jun 2021 09:52:45 +1000 (AEST) 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 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 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Randy Dunlap , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andy Lutomirski , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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?