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 5628B3DC4AB; Fri, 1 May 2026 16:06:30 +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=1777651598; cv=none; b=dW5SDvkyxngEwNZFqOaIkMLfp5HlPccXsFkVvkVyw7MEkj6BkbgXTC/06SJOYrTZbUMVrtTfuJpcfOTw5Vh4MJtZZtVc+xz0UPvCBJivMoIap6lxhpCvh+VA4Uy+hvYULRzLDeNjKx0mjLlpNURFPmrPopJTNhTtb04E0mbj3cM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777651598; c=relaxed/simple; bh=uzJ2PI/5irzqcFSPjVCx7mCAKDQ9nari3HG292g6H0I=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FkzwCoiOJ1LTTGJAo2IRt6pEWvB7Zxip22hI1+6jmS9KNbkgdIy08pI+6vm+VghWdiYLBm+6PA1kPqhpj53awPGqK9kDoD2rBIocmNw6AFEichZmX7ey8iCqSGmTsISNLWMZQh8RecSOHk1OxrUzcwmhlLJ1ucCiCmeDtt9Biwc= 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=WFSklIdw; 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="WFSklIdw" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=HCOnYxAIgiWvR0Bg9Z3oQP7NtLB+AbBygf9mhxuV9oQ=; b=WFSklIdwMHQLNKo0hSt8FUEdor 8PWAceSimwETsGI72z85Zv4wA/tsNlycLa8f6sQG/Aw6w8RnhXi0Af5mjum18LwybDyAvb1+Uxh9f Eq5T7ug+O10pWFjftTfOmniisY01PyMq7+2peSvdamJ+AAvHZRIQTazUoIUXsplGALDIdW/42jR8p U9uUO/7PltvaGp/EEhx55GmxP2PijjP4N8jL7/SdhnE0m0apJTc1yrnAE6WrXuehMZUnK54FJ0YvF M5qMff6H54NLzO+TN+U51R/JiQDmY0k5rW4FXREurwavyb9AebilT1ieN2HbK2yQvGHgLvA2FHU0e rgYRe6xw==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1wIqNP-000000091GR-0gTr; Fri, 01 May 2026 16:06:03 +0000 Date: Fri, 1 May 2026 17:06:02 +0100 From: Matthew Wilcox To: Lorenzo Stoakes Cc: "Barry Song (Xiaomi)" , akpm@linux-foundation.org, linux-mm@kvack.org, david@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, 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 Subject: Re: [PATCH v2 0/5] mm: reduce mmap_lock contention and improve page fault performance Message-ID: References: <20260430040427.4672-1-baohua@kernel.org> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Fri, May 01, 2026 at 04:52:12PM +0100, Lorenzo Stoakes wrote: > After a brief eyeball I share Matthew's assessment, I really don't like this > series, it's piling on complexity for what seem like niche cases. I don't think they're niche cases ... I think it's a real problem. While our current code performs better for this workload than the pre-vma-lock code did, it doesn't perform as well as it could. > We already have enough weirdness in fault code honestly. > > Let's maybe discuss at LSF if you're attending? Not only is he attending, there's a topic scheduled (currently 10:30 on Wednesday).