From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-98.freemail.mail.aliyun.com (out30-98.freemail.mail.aliyun.com [115.124.30.98]) (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 DDA8E28F948 for ; Tue, 12 May 2026 02:35:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.98 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778553312; cv=none; b=Ewo3lPD/XCieCAkWA79TB/bgnVNnzmlC1QrjAaA+QTC+SfYiZnqbNyf+PKb2IMWc4iKbmznWpL3sk0tDjVDPHab0WyGFyy0JyWFzWrUE/VTg6SSE/ZyaCIag4X4rdKSlTklcBxv++btd80ft326UHWzcoZ96hOnI2IIJcWJFxfg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778553312; c=relaxed/simple; bh=TwsC8b/W0xwDHFDEpsueEnExNEPbaY38rUUQT6SkMV4=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=hTDCy0d6YQvVeRAn9HIrGjLxq5OT+nnkPVxTHVJkPa2ZvkDatLOY60qxi3vy8nb3v0n/jlP8vs5sBd1BCT1o4OxuhBg+XGETKIk7ZHNLamPDoBCi1QrsV499hao1kEOjK0zKjO3GiAeQ/B6XUTZlx2bonOlbfuVo+KRK/rA7CYM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=DA+bB7Rt; arc=none smtp.client-ip=115.124.30.98 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="DA+bB7Rt" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1778553307; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; bh=ZryK6TtFL9lwH8VtNqHCwypE9vBCEHYayhdvZkF1tGM=; b=DA+bB7RtbN7CyJzNtrhFk5FM2sqPRQEURsW4jNcXcI/xdI5tNf/W+Bt8HqEKg8BqxQPQklYEadUA+3VCdYahRhAB0qJ8dNFwF+jZ2YveoDzXYaoTv7lMQOLGqSiiI7Q61vQhFaBzFPIgqrQL6hN3/8HaoLhPdx3A2uvzRZv0sCI= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R171e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037009110;MF=ying.huang@linux.alibaba.com;NM=1;PH=DS;RN=44;SR=0;TI=SMTPD_---0X2op7A9_1778553302; Received: from DESKTOP-5N7EMDA(mailfrom:ying.huang@linux.alibaba.com fp:SMTPD_---0X2op7A9_1778553302 cluster:ay36) by smtp.aliyun-inc.com; Tue, 12 May 2026 10:35:03 +0800 From: "Huang, Ying" To: "David Hildenbrand (Arm)" Cc: Shivank Garg , akpm@linux-foundation.org, kinseyho@google.com, weixugc@google.com, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, willy@infradead.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, gourry@gourry.net, apopple@nvidia.com, dave@stgolabs.net, Jonathan.Cameron@huawei.com, rkodsara@amd.com, vkoul@kernel.org, bharata@amd.com, sj@kernel.org, rientjes@google.com, xuezhengchu@huawei.com, yiannis@zptcorp.com, dave.hansen@intel.com, hannes@cmpxchg.org, jhubbard@nvidia.com, peterx@redhat.com, riel@surriel.com, shakeel.butt@linux.dev, stalexan@redhat.com, tj@kernel.org, nifan.cxl@gmail.com, jic23@kernel.org, aneesh.kumar@kernel.org, nathan.lynch@amd.com, Frank.li@nxp.com, djbw@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 0/7] Accelerate page migration with batch copying and hardware offload In-Reply-To: <98a16642-35b7-4cf9-9ee2-8de15e877920@kernel.org> (David Hildenbrand's message of "Mon, 11 May 2026 17:53:24 +0200") References: <20260428155043.39251-2-shivankg@amd.com> <98a16642-35b7-4cf9-9ee2-8de15e877920@kernel.org> Date: Tue, 12 May 2026 10:35:02 +0800 Message-ID: <874ikdwe21.fsf@DESKTOP-5N7EMDA> User-Agent: Gnus/5.13 (Gnus v5.13) 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=ascii "David Hildenbrand (Arm)" writes: > On 4/28/26 17:50, Shivank Garg wrote: >> This is the fifth RFC of the patchset to enhance page migration by [snip] > >> >> 3. Per-caller offload selection: Today eligibility is by migrate_reason >> only. Some are latency-tolerant, others may be not. Is reason the >> right granularity, or do we want a per-caller hint? > > Isn't it sufficient to just do it based on the #folios or sth like that? > > If someone migrates a handful of folios, latency is likely more important (and > batching less beneficial). > > I'd assume when migrating many folios, batching could just always be done. Or > what's the concern? IIUC, for callers like migrate_pages syscall, it's possible that almost all folios of a process are passed to migrate_pages(). However, I think that we still need to keep the folio inaccessible time reasonable. [snip] --- Best Regards, Huang, Ying