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 EA3F7C28B20 for ; Wed, 2 Apr 2025 04:29:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 97C6C280003; Wed, 2 Apr 2025 00:29:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 90666280001; Wed, 2 Apr 2025 00:29:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7A615280003; Wed, 2 Apr 2025 00:29:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 5AFCD280001 for ; Wed, 2 Apr 2025 00:29:16 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id D968480E1C for ; Wed, 2 Apr 2025 04:29:16 +0000 (UTC) X-FDA: 83287824312.19.3415C57 Received: from out-183.mta0.migadu.com (out-183.mta0.migadu.com [91.218.175.183]) by imf22.hostedemail.com (Postfix) with ESMTP id 0FC1BC000B for ; Wed, 2 Apr 2025 04:29:14 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=CUbBeCGr; spf=pass (imf22.hostedemail.com: domain of shakeel.butt@linux.dev designates 91.218.175.183 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1743568155; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=5NR6EYwPfMVgROEL2dm2qwR6XWAXVQz6akFvE7Z2xsQ=; b=JKgeHCYTFZlGPDB+Ogm6ewD+jiWOnUQLN42QzXIJywOxytk+q07lW4uT+pUQrUntWxB9wR 8Q2KkW39c6VZr2sLYIyWNIi9NPnz+uotHLbgWrRJcdhaJJrpeLdtFA1Dkr5MrkwPSIjQ9F a9xcujqCmEOEUDG8SZm4dQq1o0oCKXs= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=CUbBeCGr; spf=pass (imf22.hostedemail.com: domain of shakeel.butt@linux.dev designates 91.218.175.183 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1743568155; a=rsa-sha256; cv=none; b=LRZHndjUg5om+y2rgs5Kp8ylA0vp3mh1EuK06It2DoNoJTXceIFGWhbsFa2oAfW8256ZvV OO/2fusAjLij6/Kai0w7C9nneQy1xUU6diBfP+XatR+bf2BgJy5pacweftfbM7zVEfCGV5 Mb3aNaWWydiWR3IDiqpkplnFK4i8j3I= Date: Tue, 1 Apr 2025 21:29:05 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1743568152; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5NR6EYwPfMVgROEL2dm2qwR6XWAXVQz6akFvE7Z2xsQ=; b=CUbBeCGrruCoHQ6IlqtWfosAvZqvkFo19JVTp1duPxjt22wc7Ry5Wjtzw+OT/AUu1jC4Jx HEhHxMx4b33kLiKgEdamAdAna+os8TUq+AhYOLi25Ban6lb7+cjd6CCbMlPd1KTy9hu4Ez eMz/DqvFtSpu7tGZpp3LzTSzbAo/IRc= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Shakeel Butt To: Alexei Starovoitov Cc: Linus Torvalds , bpf@vger.kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, akpm@linux-foundation.org, peterz@infradead.org, vbabka@suse.cz, bigeasy@linutronix.de, rostedt@goodmis.org, mhocko@suse.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH mm] mm/page_alloc: Avoid second trylock of zone->lock Message-ID: References: <20250331002809.94758-1-alexei.starovoitov@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250331002809.94758-1-alexei.starovoitov@gmail.com> X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: 0FC1BC000B X-Rspamd-Server: rspam05 X-Rspam-User: X-Stat-Signature: yfk5f3w8ngfsoqn8syhcj5uoxzqmftx3 X-HE-Tag: 1743568154-171183 X-HE-Meta: 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 pcH0qWNK DJkZ8nEv6Dt3ASqs= 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 Sun, Mar 30, 2025 at 05:28:09PM -0700, Alexei Starovoitov wrote: > From: Alexei Starovoitov > > spin_trylock followed by spin_lock will cause extra write cache > access. If the lock is contended it may cause unnecessary cache > line bouncing and will execute redundant irq restore/save pair. > Therefore, check alloc/fpi_flags first and use spin_trylock or > spin_lock. > > Suggested-by: Linus Torvalds > Fixes: 97769a53f117 ("mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation") > Signed-off-by: Alexei Starovoitov Reviewed-by: Shakeel Butt