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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DEA63C61DA4 for ; Fri, 3 Feb 2023 07:19:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231462AbjBCHTl (ORCPT ); Fri, 3 Feb 2023 02:19:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232547AbjBCHTd (ORCPT ); Fri, 3 Feb 2023 02:19:33 -0500 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DE6E719A8 for ; Thu, 2 Feb 2023 23:19:22 -0800 (PST) Received: by mail-pl1-x62d.google.com with SMTP id d3so4393896plr.10 for ; Thu, 02 Feb 2023 23:19:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=x14kRrZZe2kdSbgJ1PJqUMQQfgWflSMZWL5LFkwvByE=; b=h7nAnXYffJkXAeKtJ4+Pb47ZmdkwzoIxpzRgCBuRqFSEuDy+TP7MF7IO/iVxeE9h3P aG7Esd2gb18pAjYT42bsVp7oBg2AItWYJWILKrT1Rv1wljyPlzKVe3HEajToWCRcZVtL zy4qIqHGZ3aoBW3DgCSA/Vp7o+H66URuFiIddPmq0wydnig1tvUkwDog28Na9VCQmXCY VaSnJ2jOszZ6JD6S3Lt/kqQ/A4667tSOoYJbLAZ3Dg/8Mt+fnJ7poqcB8fdgDCdZgr9h DFZ/UDXahTH+Bf05/C7Y+Y3gm5kj6MbI54iJLvql0E7GMYErZm9nVGNUKj5tyaG4S5jq 3YEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=x14kRrZZe2kdSbgJ1PJqUMQQfgWflSMZWL5LFkwvByE=; b=HVHPJwXOb02PbJNy7HJU9k0e3f7TTNHQdeZt6DFUjLQ8p0nTk+KjFgYiOEgqYGrugY 9uMVEKvhOKTLXSMHJEqaAtsO44GflbivhCXP6ItNZseP3aULpzizZLovX/MkJ2fblj6Q b8Z6JxgVtQk1FASOqIyaFYRps+7f0RFdW/MFrbU2R6n1S1MTL2BTXEHVIX1cfhDx9GsW Johf73cRnlwow9+7yJns4S3rhaSlKetGYDmhrAb0S4v7bIXVTgV12/78506eflvus2Fc IoJSbmqKBr+IJ5SxUrHoEcz1kUc1t7BM6PpJQ5sUVv0r9kUr0Qx1XzD9RftGHgxz+XS5 FPDg== X-Gm-Message-State: AO0yUKUyAnKGvhCmWSRtOuzDzZd8khWcbKAGHQSket5ukeAZW3GWVgsH RuPyH6ykUp1Lc/hQmmDReh4= X-Google-Smtp-Source: AK7set/pN1qkE5vW6sEUJPLmtT3NU/AerHL7q01jFwtmVHRhEkUBx1PKvOIigiSi96c+JcvQpUaLgA== X-Received: by 2002:a17:90a:11:b0:22c:8dfe:d6a6 with SMTP id 17-20020a17090a001100b0022c8dfed6a6mr9294792pja.4.1675408762194; Thu, 02 Feb 2023 23:19:22 -0800 (PST) Received: from bobo.ibm.com (193-116-117-77.tpgi.com.au. [193.116.117.77]) by smtp.gmail.com with ESMTPSA id f20-20020a637554000000b004df4ba1ebfesm877558pgn.66.2023.02.02.23.19.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Feb 2023 23:19:21 -0800 (PST) From: Nicholas Piggin To: Andrew Morton Cc: Nicholas Piggin , Linus Torvalds , Nadav Amit , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Catalin Marinas , Will Deacon , Rik van Riel , linux-arch@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v7 5/5] powerpc/64s: enable MMU_LAZY_TLB_SHOOTDOWN Date: Fri, 3 Feb 2023 17:18:37 +1000 Message-Id: <20230203071837.1136453-6-npiggin@gmail.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20230203071837.1136453-1-npiggin@gmail.com> References: <20230203071837.1136453-1-npiggin@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-arch@vger.kernel.org On a 16-socket 192-core POWER8 system, the context_switch1_threads benchmark from will-it-scale (see earlier changelog), upstream can achieve a rate of about 1 million context switches per second, due to contention on the mm refcount. 64s meets the prerequisites for CONFIG_MMU_LAZY_TLB_SHOOTDOWN, so enable the option. This increases the above benchmark to 118 million context switches per second. This generates 314 additional IPI interrupts on a 144 CPU system doing a kernel compile, which is in the noise in terms of kernel cycles. Acked-by: Linus Torvalds Signed-off-by: Nicholas Piggin --- arch/powerpc/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index b8c4ac56bddc..600ace5a7f1a 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -265,6 +265,7 @@ config PPC select MMU_GATHER_PAGE_SIZE select MMU_GATHER_RCU_TABLE_FREE select MMU_GATHER_MERGE_VMAS + select MMU_LAZY_TLB_SHOOTDOWN if PPC_BOOK3S_64 select MODULES_USE_ELF_RELA select NEED_DMA_MAP_STATE if PPC64 || NOT_COHERENT_CACHE select NEED_PER_CPU_EMBED_FIRST_CHUNK if PPC64 -- 2.37.2