From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 A99F135DA75; Wed, 20 May 2026 21:16:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779311780; cv=none; b=rNkQ7MJmYLFl6f3Xtp4msBGZSnxte6r8V4coTJdHLVkVdwWrr3bDnMKWPysffb/d1yS6qOoEKG81nUs26hZnxo7oPuNF2ROMv/VeyfYKejyrwClHHQ2/47SNt1GyEuUOZrZgJcAZulPoZdRznLFVexmPlNO4TRIaEAi2pTlmLMI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779311780; c=relaxed/simple; bh=fU02cunUf5qx+CTJ998toCQden5I5L9eTw1htlE14B4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nZM9gh/aJF5/H3Lh8npVRKqVAyEbT9PDmfocfThEnzxeYG+K0pi3knI7VuC5qkirBRFs0vsSGC8v4CcesqoP2tE+G/LZui58j4dTZHAKeSSfR2h4MV7+nmGRDTLtVmxvR+K5SvMC+6gFb4FFo1Uawv4Csbqe5l/pb15bS7sBYuE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Ahb0j2Ei; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Ahb0j2Ei" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=fU02cunUf5qx+CTJ998toCQden5I5L9eTw1htlE14B4=; b=Ahb0j2Ei6nx5qSArSbx3QXwe7j nN0qnERaYLGpASZAP09LlU+EPQowKBvJPWhRsI00juo+im78mkgYHs+sP5ZWwXXBd7zRVmKWFHh91 ozzCsrVpwBFURX4JqqoPT0iEmX8E9NvxsJFClE4jAwVlL4pGe782qw3PvR74tDYThCZ3q+fwmuY2k TzdU054pRFbgWK4qDrlWLvQekRsHk+y4KM+0uWUFsCECk4H+2CGnBJFwpoiJbHR/MvjI7M4kc/Ssx zg1lHxgjWogJBSyWKXMDALCFwuerNCe/Tci5nkDTpyDfHMo2R9PAJoJdp1sxjZy6+MelEhK4vLDAA A5g2JMmA==; Received: from willy by casper.infradead.org with local (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPoGl-00000007air-0tv9; Wed, 20 May 2026 21:15:59 +0000 Date: Wed, 20 May 2026 22:15:59 +0100 From: Matthew Wilcox To: Barry Song Cc: "Liam R. Howlett" , Suren Baghdasaryan , Lorenzo Stoakes , akpm@linux-foundation.org, linux-mm@kvack.org, david@kernel.org, vbabka@kernel.org, rppt@kernel.org, mhocko@suse.com, jack@suse.cz, pfalcato@suse.de, wanglian@kylinos.cn, chentao@kylinos.cn, lianux.mm@gmail.com, kunwu.chan@gmail.com, liyangouwen1@oppo.com, chrisl@kernel.org, kasong@tencent.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, youngjun.park@lge.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Nanzhe Zhao Subject: Re: [PATCH v2 0/5] mm: reduce mmap_lock contention and improve page fault performance Message-ID: References: <5zdaa5uv5oj27q3taopl3amops57ouxgyfsdveudz4ovmbdw7z@6lwrlyvmhcp2> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, May 21, 2026 at 05:14:20AM +0800, Barry Song wrote: > My understanding is that we should not blame applications here. This is 2026: > there are basically only two kinds of applications — single-threaded and > multi-threaded — and single-threaded applications are nearly extinct. all of the applications i run are either single threaded or don't fork. what multithreaded applications call fork?