From patchwork Fri Apr 26 14:45:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Matthew Wilcox X-Patchwork-Id: 13644921 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 EB402C4345F for ; Fri, 26 Apr 2024 14:45:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7EDEC6B009B; Fri, 26 Apr 2024 10:45:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 776746B009C; Fri, 26 Apr 2024 10:45:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 63DEB6B009D; Fri, 26 Apr 2024 10:45:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 459FD6B009B for ; Fri, 26 Apr 2024 10:45:22 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 51D28A0B8A for ; Fri, 26 Apr 2024 14:45:21 +0000 (UTC) X-FDA: 82051956042.07.B56782D Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf07.hostedemail.com (Postfix) with ESMTP id AED3F40013 for ; Fri, 26 Apr 2024 14:45:19 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="avEdWTM/"; spf=none (imf07.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1714142719; a=rsa-sha256; cv=none; b=temu3ip+neaczJmdN+qSd9C4+LsL0EPp6GegUGGWE12LB+UCx3wo7JnpTtPlN1GUm74+Lq 6Sas9XhjSEJ2Gq1lLHVfMxfoYZHtWBdDfTUe01zxKdwoagyRkHt4rWtfqG1LQUHFhvVyx2 TM2WAayokC9JvJMH9nHMDm0frC56oKA= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="avEdWTM/"; spf=none (imf07.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1714142719; 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=xiasNW2bjz4XwywyYv4zK4GYnJbH5N9m8U5+b7/FG0g=; b=4vb6QfTgAXtKIdwnwgD7okvoXYcqQhuqg/k5aRjdN3kfPdwgSJEi7AbezrtQFEB5nLcJFj TpZ3rTua5+n0REvvJT5WhG+WlyN3ibsHqFunDTT0X/AV2qMOUtFMcv3l6Ljeeel0WSlMV4 5IEdYmkKhayMSx1twWKsmeP6DeoSHFU= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=xiasNW2bjz4XwywyYv4zK4GYnJbH5N9m8U5+b7/FG0g=; b=avEdWTM/yAlNRrylBNlMhcItT8 yT3lf5sbN2RA11wRK57vjoI6+cQ4lOshf22Lj4uL7AZ/b1ZfApFJfPwIoV+o5X89LxrtQKmovdkWp d6GdOd+oLFrtddsrmgjkb3tHhclq/QbDFb2K9UAk9I0CHB+msjtBqcV+NNzBx3RflOlaD9xy8Dxhk es3hCflPEq9bjg0W2B3ZvZt2nuIbUQ94Vbc6N/36fbLOt32SrhktKVGwgIfqJcg4UWo/Y/MU/xiW+ LQeO3PqBRGk0YU47AeSqIQtKcSKBURhocodIXVgGTbeLOQplgj5BFtuB0HLDEw1g+kXORauvDvxQ1 4dMG+cJw==; Received: from willy by casper.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1s0Mp2-00000005Pl6-1hWT; Fri, 26 Apr 2024 14:45:08 +0000 From: "Matthew Wilcox (Oracle)" To: Andrew Morton Cc: "Matthew Wilcox (Oracle)" , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Suren Baghdasaryan , Peter Xu , Jann Horn Subject: [PATCH 4/4] mm: Optimise vmf_anon_prepare() for VMAs without an anon_vma Date: Fri, 26 Apr 2024 15:45:03 +0100 Message-ID: <20240426144506.1290619-5-willy@infradead.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240426144506.1290619-1-willy@infradead.org> References: <20240426144506.1290619-1-willy@infradead.org> MIME-Version: 1.0 X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: AED3F40013 X-Stat-Signature: ffroes6j1twr58fz6oz1ge817q4tir3h X-Rspam-User: X-HE-Tag: 1714142719-944121 X-HE-Meta: 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 zuHP3V9+ cZ7QRdh5+X0eIKKCnfrhswPNXLwZ078wh1Zla2P6WLWuaGsbg/CiDdWAv4mGUc85LFlaWej+rOZ2P3qMC2N40Oksmxu/j6O7jEdvwRsUR3zhJXxKQQuY6gI9kI9yeOMl3fhjXFPUYzqTj9FA9TCuzxd+4RZrJg5aNAwkk9MV1iYwxHm6DQ7QLkq4qiwHjbGkfYYw+x9EiC0F8t83wpeyZ7tOd4qhyMv3hVfcXLMYSnWRCWV/5KQQMbCaldw== 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: If the mmap_lock can be taken for read, we can call __anon_vma_prepare() while holding it, saving ourselves a trip back through the fault handler. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Jann Horn Reviewed-by: Suren Baghdasaryan Reviewed-by: David Hildenbrand --- mm/memory.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/mm/memory.c b/mm/memory.c index 7dc112d3a7e4..b5453b86ec4b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3232,16 +3232,21 @@ static inline vm_fault_t vmf_can_call_fault(const struct vm_fault *vmf) vm_fault_t vmf_anon_prepare(struct vm_fault *vmf) { struct vm_area_struct *vma = vmf->vma; + vm_fault_t ret = 0; if (likely(vma->anon_vma)) return 0; if (vmf->flags & FAULT_FLAG_VMA_LOCK) { - vma_end_read(vma); - return VM_FAULT_RETRY; + if (!mmap_read_trylock(vma->vm_mm)) { + vma_end_read(vma); + return VM_FAULT_RETRY; + } } if (__anon_vma_prepare(vma)) - return VM_FAULT_OOM; - return 0; + ret = VM_FAULT_OOM; + if (vmf->flags & FAULT_FLAG_VMA_LOCK) + mmap_read_unlock(vma->vm_mm); + return ret; } /*