From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B3401B422F for ; Mon, 30 Dec 2024 18:06:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=96.67.55.147 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735581988; cv=none; b=RLnnz8zzdmGMziKIvC9a/k1ak22pe7fUoYfMKPa2Z6bLHGyQhVE2GxJckgYqruBMmZ0q/lzBwWIYUsugIRu9buE3AqD2eQZoNNuhgMvZ4G7stp8uf+ibS0UHlFMdDvmsWNQmehmlfbVy4Uk58tEK1uCjzj12v2hxGuyFvR6Wlcs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735581988; c=relaxed/simple; bh=OtAv6GRfSIOgo7hIA7WVqawGSav28XPEnv3ucG67peI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jitPTvCrZ22ykbOfmLXikVZqirKUOxpcHydWj5nuS+Yj2Gr/Nf6fM5l9fwimfuxMCUk4V8Sut4stggXI3BM8MsjVAEw2b2aFKrKwJFq1x3IwN1e8vmX89K/gXErGC8fPp1uBgn7Ipu+HybXuawLLLHbkDep+3RtUQxsYluIxrM4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com; spf=pass smtp.mailfrom=shelob.surriel.com; arc=none smtp.client-ip=96.67.55.147 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=surriel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shelob.surriel.com Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1tSJzf-000000008Lf-0ChP; Mon, 30 Dec 2024 12:55:55 -0500 From: Rik van Riel To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, akpm@linux-foundation.org, nadav.amit@gmail.com, zhengqi.arch@bytedance.com, linux-mm@kvack.org, Rik van Riel Subject: [PATCH 10/12] x86,tlb: do targeted broadcast flushing from tlbbatch code Date: Mon, 30 Dec 2024 12:53:11 -0500 Message-ID: <20241230175550.4046587-11-riel@surriel.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241230175550.4046587-1-riel@surriel.com> References: <20241230175550.4046587-1-riel@surriel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: riel@surriel.com Instead of doing a system-wide TLB flush from arch_tlbbatch_flush, queue up asynchronous, targeted flushes from arch_tlbbatch_add_pending. This also allows us to avoid adding the CPUs of processes using broadcast flushing to the batch->cpumask, and will hopefully further reduce TLB flushing from the reclaim and compaction paths. Signed-off-by: Rik van Riel --- arch/x86/include/asm/tlbbatch.h | 1 + arch/x86/include/asm/tlbflush.h | 12 +++------ arch/x86/mm/tlb.c | 48 ++++++++++++++++++++++++++------- 3 files changed, 42 insertions(+), 19 deletions(-) diff --git a/arch/x86/include/asm/tlbbatch.h b/arch/x86/include/asm/tlbbatch.h index 1ad56eb3e8a8..f9a17edf63ad 100644 --- a/arch/x86/include/asm/tlbbatch.h +++ b/arch/x86/include/asm/tlbbatch.h @@ -10,6 +10,7 @@ struct arch_tlbflush_unmap_batch { * the PFNs being flushed.. */ struct cpumask cpumask; + bool used_invlpgb; }; #endif /* _ARCH_X86_TLBBATCH_H */ diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h index 5e9956af98d1..17ec1b169ebd 100644 --- a/arch/x86/include/asm/tlbflush.h +++ b/arch/x86/include/asm/tlbflush.h @@ -297,21 +297,15 @@ static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) return atomic64_inc_return(&mm->context.tlb_gen); } -static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch, - struct mm_struct *mm, - unsigned long uaddr) -{ - inc_mm_tlb_gen(mm); - cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm)); - mmu_notifier_arch_invalidate_secondary_tlbs(mm, 0, -1UL); -} - static inline void arch_flush_tlb_batched_pending(struct mm_struct *mm) { flush_tlb_mm(mm); } extern void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch); +extern void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch, + struct mm_struct *mm, + unsigned long uaddr); static inline bool pte_flags_need_flush(unsigned long oldflags, unsigned long newflags, diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index eb83391385ce..454a370494d3 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -1602,16 +1602,7 @@ EXPORT_SYMBOL_GPL(__flush_tlb_all); void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch) { struct flush_tlb_info *info; - int cpu; - - if (cpu_feature_enabled(X86_FEATURE_INVLPGB)) { - guard(preempt)(); - invlpgb_flush_all_nonglobals(); - tlbsync(); - return; - } - - cpu = get_cpu(); + int cpu = get_cpu(); info = get_flush_tlb_info(NULL, 0, TLB_FLUSH_ALL, 0, false, TLB_GENERATION_INVALID); @@ -1629,12 +1620,49 @@ 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(); + 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_broadcast_asid(mm)) { + u16 asid = mm_broadcast_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(); + } + invlpgb_flush_user_nr(kern_pcid(asid), uaddr, 1, 0); + /* Do any CPUs supporting INVLPGB need PTI? */ + if (static_cpu_has(X86_FEATURE_PTI)) + invlpgb_flush_user_nr(user_pcid(asid), uaddr, 1, 0); + } else { + 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 -- 2.47.1