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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4D774C02185 for ; Mon, 20 Jan 2025 09:56:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9CC156B0082; Mon, 20 Jan 2025 04:56:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9551E6B0083; Mon, 20 Jan 2025 04:56:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7D90F6B0085; Mon, 20 Jan 2025 04:56:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 5AAA26B0082 for ; Mon, 20 Jan 2025 04:56:37 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id C7C02AFDD3 for ; Mon, 20 Jan 2025 09:56:36 +0000 (UTC) X-FDA: 83027375592.23.464BCF7 Received: from mail-ej1-f45.google.com (mail-ej1-f45.google.com [209.85.218.45]) by imf22.hostedemail.com (Postfix) with ESMTP id B3B92C000A for ; Mon, 20 Jan 2025 09:56:34 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=eJjnkGvG; spf=pass (imf22.hostedemail.com: domain of nadav.amit@gmail.com designates 209.85.218.45 as permitted sender) smtp.mailfrom=nadav.amit@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1737366994; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=fBRCrmLG0Yxqo85lkC6rBcnkHQBGkyEmbs9MQ2abw+M=; b=unMARbuq6gJCSDglrj6LO8JEEyYMq1LF4Ygv49J3ab5hjvfWC9JHgflgVimEu5oxcoOhZF +n671JVKOQZBVmrP5rt9TqrHgrCVlmVWQzgHQ99n2WE+niadUmSLiqkjmZLPOWQTLNJpUf 5/3E6Zvm5QWKFC65ouRf7pEvcSSjQ58= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1737366994; a=rsa-sha256; cv=none; b=slZGrNyf1pt6cYGMErHQFNr06f6aFT8RyoMpKaR6nYKrvF9fcrqWlvTcb8CugiCjcdYZ7X U1qqViX47AviE1bvEm40ywcxvkkizHsyN/EhgPt6kNs7KjVKtbiBpcxStAdj5hfJ+iS/r9 +FYBLxpGS30Y99cDeWYUn6b60Y5OCwU= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=eJjnkGvG; spf=pass (imf22.hostedemail.com: domain of nadav.amit@gmail.com designates 209.85.218.45 as permitted sender) smtp.mailfrom=nadav.amit@gmail.com; dmarc=pass (policy=none) header.from=gmail.com Received: by mail-ej1-f45.google.com with SMTP id a640c23a62f3a-aaf900cc7fbso711263966b.3 for ; Mon, 20 Jan 2025 01:56:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1737366993; x=1737971793; darn=kvack.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=fBRCrmLG0Yxqo85lkC6rBcnkHQBGkyEmbs9MQ2abw+M=; b=eJjnkGvGfQbGtjdVGJUi+qtrILS8IKf69eCWplRYUd5rf3yuWgtLdbcQSKJ7RNsrhu DzFnzPQjlhr0PDyr7pqSDlMiAbzLgJyNCT1SklMfkoMBKBjgd0LIhKF79uzLXbxq16rr 4m40TIe9asSrBCKKEBa0PpmgZWd0qm97K9PShYfcrBEmJax+nw9Txl/SFM0CZcFy0xUj gwU1ilbFwBxKgmw5LFUK9GFC/REcPS9kvqYwd7zLxkP68hAmVB2FbWPCibkDNeJcWX8I aRMPTUKA1MbAuZce0hjGZlGKZMvq2hofO1KSvfEB+T0hx2c1zEB+/QH7vpHIFIt8nN2j b+7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1737366993; x=1737971793; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=fBRCrmLG0Yxqo85lkC6rBcnkHQBGkyEmbs9MQ2abw+M=; b=YUC6PY7H6k5V9DYfQxua4uNLA+8Z8GYzP17WLDx1CD+tRf9MJdpQxho9VCljVRrsua T9nThCOIUsquFGBweRXT5i1zw6oZmTz9Ma7c1fk+n+ZonUxunlSeMB6JRH8rgppYsqvn ZD4NdUDEOT4s4q03lv3fWvSHViBw8EcpmtzJAIhRqEJe8HvAFgxA7SYGAHzXoSzemiuu d8HCAf1N+qFXjixC5QdWKMmMEs+aTe/fZM48Ytx1ezafDqMVy0Aod3ptcrl4FuJhReue piKdCf2eodvLg4ltbtVgAOft2t+vdyh9L2qR0Ag36qqyhOkJE8Kv+GWhiIn+7UWYfSZ+ 9/5A== X-Forwarded-Encrypted: i=1; AJvYcCW3R9HOK3rljc4cRYPoqhHC/xLPAPOE9j7tndYG3Ay9aAp1rdLAama1tPu313Fq3+GtfWzMARHOYQ==@kvack.org X-Gm-Message-State: AOJu0YxfoDxFFKzfUATMZcqgk7qtVn8DcuxxDoJ+x3oyWL0ed5F/ReBM K3V7IzZgeH+eAFtlxIGGSeoCa/1xbi8oqMTurSOSPrHlb8vBMyjK+dOK8Uuv6ro= X-Gm-Gg: ASbGncs4AJOgAPLkG3IyIGGhLksU3TEHSkrWCOfmA0msX8EdBZJ//D4iaMDYRvtV7hw xpJjUyH6wqAcnGm527NAR+ZSDNMhMD/BboBJkgxbY5JlbdSJP2b0b6Yrczpr/s0B0DO5Mzd2JRB oHfwHJZvDC1Re+xTy1RylXK8B2SMrLbZLy5AagA9WVisM5xVBZChWyVMg7LTCDjWjveI3siPsJu WZoo12ImSpsaHG5sii3K3vBzWTziOqhNtwDh8QTqqekpFCLgNAEyYbtaJM6Hs9HRYKU30Bjq/cj VMjGIeZY8w1B X-Google-Smtp-Source: AGHT+IHQ24u/49h2prWcl3JbFEKmsEsPj68n7iFo2O0Y9kk9FhhZRxMzDfvbPI/Lz6WpJe39l1DdqA== X-Received: by 2002:a17:906:7315:b0:aa6:6c46:7ca1 with SMTP id a640c23a62f3a-ab38b0b807amr1304744566b.10.1737366992756; Mon, 20 Jan 2025 01:56:32 -0800 (PST) Received: from [132.69.243.144] ([132.69.243.144]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-ab384c61311sm603137166b.18.2025.01.20.01.56.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 20 Jan 2025 01:56:31 -0800 (PST) Message-ID: <13bc0c49-09a4-434e-bd35-1ea50be38e25@gmail.com> Date: Mon, 20 Jan 2025 11:56:29 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 10/12] x86,tlb: do targeted broadcast flushing from tlbbatch code To: Rik van Riel , x86@kernel.org Cc: linux-kernel@vger.kernel.org, bp@alien8.de, peterz@infradead.org, dave.hansen@linux.intel.com, zhengqi.arch@bytedance.com, thomas.lendacky@amd.com, kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, jannh@google.com, mhklinux@outlook.com, andrew.cooper3@citrix.com References: <20250116023127.1531583-1-riel@surriel.com> <20250116023127.1531583-11-riel@surriel.com> Content-Language: en-US From: Nadav Amit Autocrypt: addr=nadav.amit@gmail.com; keydata= xsFNBF3nSCQBEACinGNWCLb3Iptvg066zPUQCFfR0nIX+j/pjxlLd094zOKLJ7Z1wKNNTQgb +Y1GQYwKurK1hFHISPc1T7xk2twzov5niFqQp1/E0I6t/92rxo7C26tKMrCHgqXpFXXBaOvq t0QN8B83o3sfS3OZyc0F5hWoJijhKQ+h7dJHMPpBBeTWiZzYVlMNz/wRzYrh1nvesbGJtV1w Wk96qoQAOagczRaSRWouJ1O2JbHqQarLJG657hqtPZctQ1mkXQcJedT1c8ejWBdIiU0rIpV/ R2uTgM5NSjVrY5OxiS2G4C/bDcI4Q6ApWxqu1zRGffKWRFJdQvttSv+JbW2q6OCvJReJs1i6 nTovpfJb3g9d7U76LtAw7HE5iIl5CmyFoTMMH+sDc5PG7JRboiofku9DWeDGK4rB2s97GuA9 BXJDHBbH1AI+Y0H6oz/Dri1sQSayUU8Xj/jCkwxpwDle1qYYE0UM4PqDTUoeejURR/h/AREt bCecfxNUYNz2jY8PUL0YXj6yex2p1otMy5sy7djrTqhC02AXLQ3Oab2UJuMZnf4cTbN2sGXu CRXcCSsoyhxIFtwpgdVIDqkPMCOEPvUwy9hWs0N9Xy+jOebpH6FYxq83pP3IhyBdaoexoyGL IkSzrO4+0bVk5voh5SIYVkLEooMSEQT9rfSdrJmRRuM7S/PowwARAQABzSFOYWRhdiBBbWl0 IDxuYWRhdi5hbWl0QGdtYWlsLmNvbT7CwZcEEwEIAEECGwMFCwkIBwIGFQoJCAsCBBYCAwEC HgECF4ACGQEWIQRIkveiyXlibH/D0jUdoCpJptoPWgUCZWMLXAUJCz4qOAAKCRAdoCpJptoP WoWjD/0d8I+qQIHp2Eq7Whi+idkGDJaaBksRw2r0+XTzRj0CsCFJS7oMWudQaYaI2bTW9uha zfcmpnkm5aOVoxGOGJUJSy0H4of6lShE+7caoz1pdX+y15STij3+RvUjcGn0N+Mpxrnj6anm ArH5KOwzQJDiMF48ntQ2EQAFJ5X6YZ6Ed9N4I88XPeOtWaU21Q5tZI/ASHrQTH7BMukkVe2U PkSjn205vbrCfcC4Ohu9HXC8ey6l5txomFaTIRvaz1La3W8gQHhT2D2QeNnJFRudN5hQJNIE OHFi6QmPVIbI/uYD82h5uesiufycV2kvuIACmvs2T3tpaxSY9HOJF/yAhqg28hKE4wKQIwh2 wzZ+ywDeZ5TboqTjTU9oPHuRTxYItWmevJgQDwOYcssYI4wOdXvu/bh5VvhBgJxgkOOH7j8N efzqooL/2/pD/1JAO9GjPEWbuRx0dZh5tcMq/RYFFhdZQNFYmqdDyY0+y6ntxEo25ScvVLfR GqhpyJkN9+cqJZfg3IolbWoZxkSLtiCBge/EDRRoLJpjpsLpBmMmQcH/50WgQcoL5ObVlc1I ft1sKfzZvIyqXZfu3YcWgvOXfVXaMw1dXQ8ffwgyCSIsKvA5+Y45knd72SHny5z3gi1YsMc1 lm24v+OfxfmZMmJQ7TXBDl0JkOMnQ3A+KDb0oGAI6c7BTQRd50gkARAAt/NqfDSMph828JIn VOck27zsyT12AHRLIhsCCatw+zYbdMSLTW6hd/sChStdndAQlqOOW3mpm6bA+jl59c4OhkBW 8fDKgaWjVq8kBm4Z61zhzk3oXMmxgQ3cqMEfN36PCpcfs5MtLiMoa2JxaqFMQbKkmcZqz8fw qGIID/SMI5qdk+yWZSmR+6RdzXfppEIeqs78qTFxaEl+0MlAcgo2AjrMPLIjNK3k4jNAVCix KjMfkkPk6xVmP5Q7cr1st0xTTa1APt0y966oa6CZIdHY76D/jLpjJlfalctmEAxmyBqK0ZkK WDkEF+qCqqZ7oSkC1Q0ogBuBffIZb5srleqMz++IutiE4r/LELs7RanXXCRK5JYzZc/uAnxN fCJzqKR5/JxoSnCh0yQNU4FHa78DeD/SLnCu8JwTGkcX9ZUW/ZQ+5Nsimy+SlZb0UyaWA+vr Q7+F7OAL6PFsE8v+Q2u2EHwa8e2KmsL0sC+enBXbaogLFFfKi4I13vOk+76nCZTNetRhAubM etLe1PZZ0IDzgGhjFg+cc/jptq3qYjK+3jzhdKaqmoibAoea3E/5HsTVVbxUiYEdk2crTqf9 Mr5S5AzQfH19xU7uUduBvjN3L0dRKP0wJEqgCIB5gZBjD8AYmKSgdEujDAPQNXTJgwB99C+r F0XoHEmO6m9vI6djzDsAEQEAAcLBfAQYAQgAJgIbDBYhBEiS96LJeWJsf8PSNR2gKkmm2g9a BQJlYwtcBQkLPio4AAoJEB2gKkmm2g9ah7wP/jP18+dznONUt3Nga6XKYxxlVmVnMlqHx6SB jDWTwFzcQ6UeVVUmODWBSLI+iqg5djkgsTcHwI668qhIyyWaXC9ld+ONhUaE4NH1PKcJ8cdG vzhdTG8lM9mwmnJriTfih59OLI2yKpml/et44gvsfQpmFOyrdH9u6xPai5h3KyOoXD+Q3EzQ KEiHqs2x0PX72Jz4iVKEanP+qxEwzarUUcum94ecGilYY4jfxhfkgwBWjmC7ExbVTSEKIx3Q zdDbDiAxhAWymSisP3lbYqRo8mkg8r2emNan5L5Xh1b/62zmMO+p6gzucV7vO0VJxlKuUkFW 77Ug+X+hkDedvp2oRBz+wKtBxwSxlTM4toD49Jn111OMS6R5opquZP+/SJH1njSKY9MY3D3D 57QDpRUvqbqMDdqZqmYlMxntxTJ+0yksR61/t62F/bSp4XLxbgwCXMm73TxGrU73ngaS/Nxz Pv28VEcCGXZqFS2sbsbBSEjGgPhXf73YlI1fYiAFiaKHKvlofX+xNLeRHr9/+fL4JWPFurGi WYMyVA5Fv1sfefXhdEv9qNlhyNHxxB3vEpxkEOdo0JUhNfIcxe/w5iOfCUAtwUfvijvHUFHh U5QeQckJZTApjJ4S/Wa1ef8eS/LBsvG9xMNG3Ns+M+xR6unu6gTuzUNp7Zsxgmp8hs0racLB In-Reply-To: <20250116023127.1531583-11-riel@surriel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: 7tinaefjqm9sttabs6ypie1ur8eabg1o X-Rspamd-Queue-Id: B3B92C000A X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1737366994-228291 X-HE-Meta: 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 LWJVSaFC Q48ZZGesvfpGE24l1ctmljirqKz8B+SRgQ7XZFtTInjJT9xehkjCV11ZuhW+N3/mnvo0W4Ajkea/5SFwNtJURhFjkfqS2ccNNsEVt4Izw4drpJPVCllY2f+2t5GG1LHf0PwkKprR1cjz9pK3gnqwWNnNQ36myDz8LTSUj6CRXW08bSbX1P7ExiHA5qqH7JcG8QbCTcb2FNbbmm878izlsVvC2831HeNnmrUJgCKlUa87r8jbSDTsiKJ0wzgVDsDCiDjILb4IG/vS5ngfIQ19wHAQh4wCujoU/hEmkik3+Z/WNQKlQnHbDPQcAQxcHISZskKN0VHodmpoinjdI61VDACx237GEEoQdwRIeEdxs7AaBJ0hYsBQFG8ZhZjGY+kDTCgXOYQFXzO26l22MieNitT6NCBKiIIu3ClXP9tF1CaElBIVJ/YRAwRSoCQ== 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: List-Subscribe: List-Unsubscribe: On 16/01/2025 4:30, Rik van Riel wrote: > Instead of doing a system-wide TLB flush from arch_tlbbatch_flush, > queue up asynchronous, targeted flushes from arch_tlbbatch_add_pending. > [snip] > --- a/arch/x86/mm/tlb.c > +++ b/arch/x86/mm/tlb.c > @@ -1659,9 +1659,7 @@ void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch) > * a local TLB flush is needed. Optimize this use-case by calling > * flush_tlb_func_local() directly in this case. > */ > - if (cpu_feature_enabled(X86_FEATURE_INVLPGB)) { > - invlpgb_flush_all_nonglobals(); > - } else if (cpumask_any_but(&batch->cpumask, cpu) < nr_cpu_ids) { > + if (cpumask_any_but(&batch->cpumask, cpu) < nr_cpu_ids) { > flush_tlb_multi(&batch->cpumask, info); > } else if (cpumask_test_cpu(cpu, &batch->cpumask)) { > lockdep_assert_irqs_enabled(); > @@ -1670,12 +1668,62 @@ void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch) > local_irq_enable(); > } > > + /* > + * If we issued (asynchronous) INVLPGB flushes, wait for them here. > + * The cpumask above contains only CPUs that were running tasks > + * not using broadcast TLB flushing. > + */ > + if (cpu_feature_enabled(X86_FEATURE_INVLPGB) && batch->used_invlpgb) { > + tlbsync(); > + migrate_enable(); Maybe someone mentioned it before, but I would emphasize that I do not think that preventing migration for potentially long time is that great. One alternative solution would be to set a bit on cpu_tlbstate, that when set, you'd issue a tlbsync on context switch. (I can think about other solutions, but I think the one I just mentioned is the cleanest one). > + batch->used_invlpgb = false; > + } > + > cpumask_clear(&batch->cpumask); > > put_flush_tlb_info(); > put_cpu(); > } > > +void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch, > + struct mm_struct *mm, > + unsigned long uaddr) > +{ > + if (static_cpu_has(X86_FEATURE_INVLPGB) && mm_global_asid(mm)) { > + u16 asid = mm_global_asid(mm); > + /* > + * Queue up an asynchronous invalidation. The corresponding > + * TLBSYNC is done in arch_tlbbatch_flush(), and must be done > + * on the same CPU. > + */ > + if (!batch->used_invlpgb) { > + batch->used_invlpgb = true; > + migrate_disable(); See my comment above... > + } > + invlpgb_flush_user_nr_nosync(kern_pcid(asid), uaddr, 1, false); > + /* Do any CPUs supporting INVLPGB need PTI? */ > + if (static_cpu_has(X86_FEATURE_PTI)) > + invlpgb_flush_user_nr_nosync(user_pcid(asid), uaddr, 1, false); > + > + /* > + * Some CPUs might still be using a local ASID for this > + * process, and require IPIs, while others are using the > + * global ASID. > + * > + * In this corner case we need to do both the broadcast > + * TLB invalidation, and send IPIs. The IPIs will help > + * stragglers transition to the broadcast ASID. > + */ > + if (READ_ONCE(mm->context.asid_transition)) > + goto also_send_ipi; > + } else { > +also_send_ipi: I really think you should avoid such goto's. A simple bool variable of "need_ipi" would suffice. > + inc_mm_tlb_gen(mm); > + cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm)); > + } > + mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL); > +} > + > /* > * Blindly accessing user memory from NMI context can be dangerous > * if we're in the middle of switching the current user task or