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 06FC41B0427 for ; Mon, 30 Dec 2024 18:05:39 +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=1735581941; cv=none; b=GA0ZtqoY/eHIq1jLwwK1wlMQL3ZNQ7pJmlIckhXBsHPu2e4vicfp98SiYaqWWbewDOUJl1SfDHgxER44NOU0AWc1BIf9IMB+umq2HCv349vcyGd2sXXyeddgef6WT/lZpG3e4Xnx2qIbpX9iFlIZBeLcecgEUDeyPcT7Qofh740= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735581941; c=relaxed/simple; bh=UTUbLNhwSKotjeAqet+8hPX3oQbWrFlGGAfDGYkfJ3k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RCCva6GW6vUKaCHlpi8Whv4JGFOsEF/PCL+KWoETdZB515N36Ks9lgHMO1ern5BfuQ4VnNWhwFIUZALnXp6CdofBXtoGvlAw87/NjUnhGVDqzI2q2NeECEQlt7+QVtqslRiAceR1cp1gU8MygIzSzWMB9X0yg+Xymxgm7Q1RPOU= 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 1tSJzd-000000008Lf-3fUp; Mon, 30 Dec 2024 12:55:53 -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 06/12] x86/mm: use INVLPGB for kernel TLB flushes Date: Mon, 30 Dec 2024 12:53:07 -0500 Message-ID: <20241230175550.4046587-7-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 Use broadcast TLB invalidation for kernel addresses when available. This stops us from having to send IPIs for kernel TLB flushes. Signed-off-by: Rik van Riel --- arch/x86/mm/tlb.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c index 6cf881a942bb..29207dc5b807 100644 --- a/arch/x86/mm/tlb.c +++ b/arch/x86/mm/tlb.c @@ -1077,6 +1077,32 @@ void flush_tlb_all(void) on_each_cpu(do_flush_tlb_all, NULL, 1); } +static void broadcast_kernel_range_flush(unsigned long start, unsigned long end) +{ + unsigned long addr; + unsigned long maxnr = invlpgb_count_max; + unsigned long threshold = tlb_single_page_flush_ceiling * maxnr; + + /* + * TLBSYNC only waits for flushes originating on the same CPU. + * Disabling migration allows us to wait on all flushes. + */ + guard(preempt)(); + + if (end == TLB_FLUSH_ALL || + (end - start) > threshold << PAGE_SHIFT) { + invlpgb_flush_all(); + } else { + unsigned long nr; + for (addr = start; addr < end; addr += nr << PAGE_SHIFT) { + nr = min((end - addr) >> PAGE_SHIFT, maxnr); + invlpgb_flush_addr(addr, nr); + } + } + + tlbsync(); +} + static void do_kernel_range_flush(void *info) { struct flush_tlb_info *f = info; @@ -1089,6 +1115,11 @@ static void do_kernel_range_flush(void *info) void flush_tlb_kernel_range(unsigned long start, unsigned long end) { + if (cpu_feature_enabled(X86_FEATURE_INVLPGB)) { + broadcast_kernel_range_flush(start, end); + return; + } + /* Balance as user space task's flush, a bit conservative */ if (end == TLB_FLUSH_ALL || (end - start) > tlb_single_page_flush_ceiling << PAGE_SHIFT) { -- 2.47.1