From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E58E7304BA3; Fri, 1 May 2026 17:09:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777655380; cv=none; b=JJMCQD2NKarrgogZmYW8Dnk8Hwq3VdXCo34P+OT5eUqQw+6kNnEVmV+CGaoL7wL56A4l05egnRa3p3RfCpVAA+5w9kzrOTfvOmN2vMHJNNQ7ocKNXvTxDgC6uPxtWssciyljtaFFDZJXVDDMlZcjJaZ3Qm0NUSCYyus0WEhCpM0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777655380; c=relaxed/simple; bh=aCKpiD8Crlk0uEQZs9vyjBCgLqxVn32/cxl6Y0AtRGE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=T9QVSJ7t4UuIyGRQghAiPg4gHA0vtJ7rUlLq29jCbGfmuGdaD+5ob5fHVGaLJlcBJ0hkmF9JxSzhTmUyXGnDNnsOcbzjdjzEKXh9hJPc63TvbjrV4jv/RCuYbSi1rHo/QGLk1DFl2BCQBAzz+zDCURUBSi+yvQg8ILLILlpzpyU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OX2L1x4x; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OX2L1x4x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7EC2AC2BCB4; Fri, 1 May 2026 17:09:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777655379; bh=aCKpiD8Crlk0uEQZs9vyjBCgLqxVn32/cxl6Y0AtRGE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OX2L1x4xFIxbScfPDUbir6mmS+xdX9NmUYzJR0EJkE7ri86qbaeUTkDb4jWI5oeb+ aN4JbRR+N5UIrCNNa22w2pCZ2JSMSHoSZwNy2T2qFiVEenmDxH9tkupv+ZDyGU2ObI 654hr8gYpcXDtcmeRIPh1KdMIPoWk95vpdUy3GSPXi4IHKF8A7wxn55TDFMfm9T3X7 2RVfuwK5n/jkaekIr44u2S02mSaPb7gcycVdlcOtlmx86ngcN1rcmImzOHzRA44jyl l2G+a79TnBeaUy0DKnFo0u2dmfaqSvsLz/R2tzsXHpnuJk6XOz3vggn1h43+SNrKA+ 0+Ne8WhoVmpcw== Date: Fri, 1 May 2026 18:09:30 +0100 From: Lorenzo Stoakes To: Matthew Wilcox 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 05:06:02PM +0100, Matthew Wilcox wrote: > 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). Well then, let's revisit this in person in Zagreb :) Cheers, Lorenzo