From patchwork Wed Nov 9 16:51:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kirill A. Shutemov" X-Patchwork-Id: 13037755 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 553AFC43219 for ; Wed, 9 Nov 2022 16:52:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5EA726B007D; Wed, 9 Nov 2022 11:52:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 499BE6B0074; Wed, 9 Nov 2022 11:52:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E0E518E0002; Wed, 9 Nov 2022 11:52:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id C69CB6B0074 for ; Wed, 9 Nov 2022 11:52:18 -0500 (EST) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 98DEF1C5CFC for ; Wed, 9 Nov 2022 16:52:18 +0000 (UTC) X-FDA: 80114496756.19.ACBFD01 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by imf10.hostedemail.com (Postfix) with ESMTP id 00286C0002 for ; Wed, 9 Nov 2022 16:52:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668012738; x=1699548738; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=qQuq8QNGbNiZCBzAMV30JlXBLCHT9H1+EgK3GfrClpQ=; b=bezy8Cw0St5jHhQoryIEf25D/FCYN5rLw/0LCFYGr+6Ut/pJXBr3bGpy sFXV3bW508n3ziuBLRyjpNSftRs5zgdeIoJ5sxKJ5UC4laPd2l16QmPjH /73KU+mj8X/xxnmqIvlxLHlEdwMn+k5jrWdkcDoVrWZhzNlyRWJjxbMEg cM0whg/aExMY/DSa3AXQhXKpsjgev2bnPFONRHP4vH9hBfERxodlEt2xm CXg7Y4qxn9Iz3XHePpHZXW6uPFMvI120s5ZiB0k23JbkJG5a0Vwu5Q07P jL8cm7ImbJspXqmvnI26C7/BmyPl+2NoNVB6zfE7XXnC+7UP5v5ZlR9r2 w==; X-IronPort-AV: E=McAfee;i="6500,9779,10526"; a="311026956" X-IronPort-AV: E=Sophos;i="5.96,151,1665471600"; d="scan'208";a="311026956" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Nov 2022 08:52:16 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10526"; a="587827255" X-IronPort-AV: E=Sophos;i="5.96,151,1665471600"; d="scan'208";a="587827255" Received: from dschramm-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.251.219.85]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Nov 2022 08:52:10 -0800 Received: by box.shutemov.name (Postfix, from userid 1000) id A93E0109474; Wed, 9 Nov 2022 19:52:00 +0300 (+03) From: "Kirill A. Shutemov" To: Dave Hansen , Andy Lutomirski , Peter Zijlstra Cc: x86@kernel.org, Kostya Serebryany , Andrey Ryabinin , Andrey Konovalov , Alexander Potapenko , Taras Madan , Dmitry Vyukov , "H . J . Lu" , Andi Kleen , Rick Edgecombe , Bharata B Rao , Jacob Pan , Ashok Raj , linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCHv12 08/16] x86/mm: Reduce untagged_addr() overhead until the first LAM user Date: Wed, 9 Nov 2022 19:51:32 +0300 Message-Id: <20221109165140.9137-9-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221109165140.9137-1-kirill.shutemov@linux.intel.com> References: <20221109165140.9137-1-kirill.shutemov@linux.intel.com> MIME-Version: 1.0 ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1668012738; a=rsa-sha256; cv=none; b=UQqnDU8OQLpS1xO++W8HGA/Vs+FM9WhlevfUL5GXZSTax8fQvOEUPGuYEibDy+JSvf9Vry QmLuLdo3d1uMJS+U8gbvskctzJJqF/uc48gGAc/yQKBNiT3RcPfxoPaq1zI5UJsPuBN5Fp xRrQOrgPMRHRkdjOBwidfZ+6rGWJlug= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=bezy8Cw0; spf=none (imf10.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1668012738; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=kTxhWdg/9+KWVLyknAx/c07RpH6UpatcZ0+k9lSUfcM=; b=tVZ/GRqr9I84VuZQT8H/HUjEyQwm96Dtf+8qcXujTpAUHiy1B+5bnQhEdCDffh7tC1lTQd 8WTnoL/sLYloCN6Enz2gyr57qs+q/U5ixfJvs8/9MV1XtD+il822p3mptrwOFbZwRwBEzM 3BOKfgy7wP7/o4yAKrW0xDqI0RcA+lo= Authentication-Results: imf10.hostedemail.com; dkim=none ("invalid DKIM record") header.d=intel.com header.s=Intel header.b=bezy8Cw0; spf=none (imf10.hostedemail.com: domain of kirill.shutemov@linux.intel.com has no SPF policy when checking 192.55.52.115) smtp.mailfrom=kirill.shutemov@linux.intel.com; dmarc=fail reason="No valid SPF" header.from=intel.com (policy=none) X-Rspamd-Server: rspam12 X-Rspam-User: X-Stat-Signature: ys185iwbxk5urbwzify79kbm81z9b9r6 X-Rspamd-Queue-Id: 00286C0002 X-HE-Tag: 1668012737-839026 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: Use static key to reduce untagged_addr() overhead. The key only gets enabled when the first process enables LAM. Signed-off-by: Kirill A. Shutemov --- arch/x86/include/asm/uaccess.h | 8 ++++++-- arch/x86/kernel/process_64.c | 4 ++++ 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h index 0db6f5451854..1d2c79246681 100644 --- a/arch/x86/include/asm/uaccess.h +++ b/arch/x86/include/asm/uaccess.h @@ -23,6 +23,8 @@ static inline bool pagefault_disabled(void); #endif #ifdef CONFIG_X86_64 +DECLARE_STATIC_KEY_FALSE(tagged_addr_key); + /* * Mask out tag bits from the address. * @@ -31,8 +33,10 @@ static inline bool pagefault_disabled(void); */ #define untagged_addr(mm, addr) ({ \ u64 __addr = (__force u64)(addr); \ - s64 sign = (s64)__addr >> 63; \ - __addr &= (mm)->context.untag_mask | sign; \ + if (static_branch_likely(&tagged_addr_key)) { \ + s64 sign = (s64)__addr >> 63; \ + __addr &= (mm)->context.untag_mask | sign; \ + } \ (__force __typeof__(addr))__addr; \ }) diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index b8f2558a3aeb..457f79be8bc7 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -743,6 +743,9 @@ static long prctl_map_vdso(const struct vdso_image *image, unsigned long addr) } #endif +DEFINE_STATIC_KEY_FALSE(tagged_addr_key); +EXPORT_SYMBOL_GPL(tagged_addr_key); + static void enable_lam_func(void *mm) { struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm); @@ -798,6 +801,7 @@ static int prctl_enable_tagged_addr(struct mm_struct *mm, unsigned long nr_bits) } on_each_cpu_mask(mm_cpumask(mm), enable_lam_func, mm, true); + static_branch_enable(&tagged_addr_key); out: mmap_write_unlock(mm); return ret;