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 EE61416EB4C for ; Tue, 18 Jun 2024 20:05:39 +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=1718741140; cv=none; b=pQ44lBV9ZUlUmXoH3R3bZ1/c+FVba9HYAHmeqnj7KVp2617naLYUo9whajF8ATYxoKfwzZKPAbGh+ncU9BKkeF552jrr/aapP3KwsTQd7Wvt2UbvRRuhrSGKCtzuet4r12AZ8p1cZCYH0FEsnbvE9gTbuKwaU7q/C/GEoMm4PkQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718741140; c=relaxed/simple; bh=Q3cL9NGd/2gb60TlkW0zKQw7uwMcaoAmw21Ymu4oJHM=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=P/gvmKam1Jms81LASTI4qJX0JSQCZ22sWzgL0irmfcENqiMpkq9t7eewIwm/2fUmh0MLWuqPFPxm91IDjoUBsTFflmsn9vWLcUOuE/gkB6dupu9/o9UaIZ2jKq83nfcbKiIrp6uwEB0yroRMvfwOfuS6LL149w3qO4F5YrktxUo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=QLcIv/mt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="QLcIv/mt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 44619C3277B; Tue, 18 Jun 2024 20:05:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1718741139; bh=Q3cL9NGd/2gb60TlkW0zKQw7uwMcaoAmw21Ymu4oJHM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=QLcIv/mtxo/nJGWDDQFN778osoFvAfAcO1FudY0cHCIrVz6eySdt1dCzPj4FjNM/U +TIqKU9R8cuMpcUPROK/leBJmcnFjQZChBL/krRCjRj1MEInSrD//rSO1d7HVuB0zH gTG4Ujj5CLKp6HPQRWg9952AVvV+Y15RkAO+tRCc= Date: Tue, 18 Jun 2024 13:05:38 -0700 From: Andrew Morton To: Baolin Wang Cc: hughd@google.com, willy@infradead.org, david@redhat.com, wangkefeng.wang@huawei.com, chrisl@kernel.org, ying.huang@intel.com, 21cnbao@gmail.com, ryan.roberts@arm.com, shy828301@gmail.com, ziy@nvidia.com, ioworker0@gmail.com, da.gomez@samsung.com, p.raghav@samsung.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 0/9] support large folio swap-out and swap-in for shmem Message-Id: <20240618130538.ffab3ce1b4e66e3ba095d8cf@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 18 Jun 2024 14:54:12 +0800 Baolin Wang wrote: > Shmem will support large folio allocation [1] [2] to get a better performance, > however, the memory reclaim still splits the precious large folios when trying > to swap-out shmem, which may lead to the memory fragmentation issue and can not > take advantage of the large folio for shmeme. > > Moreover, the swap code already supports for swapping out large folio without > split, and large folio swap-in[3] series is queued into mm-unstable branch. > Hence this patch set also supports the large folio swap-out and swap-in for > shmem. I'll add this to mm-unstable for some exposure, but I wonder how much testing it will have recieved by the time the next merge window opens? > Functional testing > ================== > I use the latest mm-unstable branch to test with reverting Chris's > "mm: swap: mTHP swap allocator base on swap cluster order" series which > can cause some problems (Hugh also reported in [4]). I dropped Chris's series from mm-unstable.