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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8EAF8CD4F3D for ; Wed, 20 May 2026 21:16:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 01FC96B008C; Wed, 20 May 2026 17:16:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F39B96B0095; Wed, 20 May 2026 17:16:10 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E768E6B0099; Wed, 20 May 2026 17:16:10 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id D7A806B008C for ; Wed, 20 May 2026 17:16:10 -0400 (EDT) Received: from smtpin12.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 827F5A03AC for ; Wed, 20 May 2026 21:16:10 +0000 (UTC) X-FDA: 84789056100.12.2BB11EF Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf13.hostedemail.com (Postfix) with ESMTP id D5BE820017 for ; Wed, 20 May 2026 21:16:08 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=Ahb0j2Ei; dmarc=pass (policy=none) header.from=infradead.org; spf=none (imf13.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1779311768; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=fU02cunUf5qx+CTJ998toCQden5I5L9eTw1htlE14B4=; b=rc/VNy67z1HSNl//x+4qdBVOR14gVtLeICxF9TkU9hqih2wN1l3ohk3a4QMEiKzwQlinUN 9iWH8BuY1Sm5xO7PDVv1TMf3kDnkDjn/hkgwsaQwluw/Buu7XrjAk2D/erxK3Xf+p3RkyD ldwH6a7UBBo5Dwmc/zHispxUKgbreB0= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1779311768; a=rsa-sha256; cv=none; b=8WzLCOLfPxqClEoevTmF5lroJjy8KNZdqIwa37429Afyae2NdfIeXm/jxyyRZwFdOzrOH3 gVTLnT8RNEXlNbhcIbInrNTz2VfaKx90tbw2W47ONWd3JgCS/xzxBghOFQ0WjuIJLoYJci I5vkhl6VOv6fRtC6eRFGqnzkQfaGeSA= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=Ahb0j2Ei; dmarc=pass (policy=none) header.from=infradead.org; spf=none (imf13.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org 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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspam-User: X-Rspamd-Queue-Id: D5BE820017 X-Rspamd-Server: rspam04 X-Stat-Signature: 6gsu9c3q6i3qtt3w7jyifzn3rs3h486f X-HE-Tag: 1779311768-869098 X-HE-Meta: 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 GMLsJ6pQ oWQv/BAaBpdIeUy4yqfyjB95KEZGlNxqLdacMXS+ldTlpExqEPg2VGp8q6GBZkO4fPiuwR8WaByqSNMDNC58wadUQ/yxQjlwNSCSRA/ODpi06v86R+JOF697/CW7AFXNDgaIidQi84JIlW8XXSHBHV2+PXDoV47J/GAhbYZ7xb9+CLxQU64yxsIjysqFvELMv9SH7Q65bsbOYgAzo+NNFuatBFCmC9J3PTXkm2BCy+biKND085qDlb2IiE5uoyMrYWUXJdlvbeAJT9v0CuozBANQZDb9pdVVLtQfwmlXYZ9JONxuTdXH4mLM8/YUlVA7iz46YKDuGhREaTLADYEAvIZ0rC0b+jbkw0OvHieN7cc+hmUDvMcae7ZZ6jY+re+x5Onh3ux80P10HGe4= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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?