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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 854B6C47DAF for ; Mon, 22 Jan 2024 06:39:22 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0C3866B0074; Mon, 22 Jan 2024 01:39:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 073FE6B007B; Mon, 22 Jan 2024 01:39:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EA41D6B007E; Mon, 22 Jan 2024 01:39:21 -0500 (EST) 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 DC4986B0074 for ; Mon, 22 Jan 2024 01:39:21 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id AE20DA0929 for ; Mon, 22 Jan 2024 06:39:21 +0000 (UTC) X-FDA: 81705995322.24.1D14FB7 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf05.hostedemail.com (Postfix) with ESMTP id 36F4A10001D for ; Mon, 22 Jan 2024 06:39:18 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=eotifFW6; dmarc=none; spf=none (imf05.hostedemail.com: domain of BATV+f852a6472c07d339093a+7456+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+f852a6472c07d339093a+7456+infradead.org+hch@bombadil.srs.infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1705905559; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Al8BzeKCJa/SU229J/wH0y+VrQO/ruk7m6AVYzxSD+Y=; b=e9N4OTD8pLG4Dzq7VcbqrVCps464TD3oVoaoo2x8E1QAqD9EH3UmErvsBXR/MQEJQWkEgG eILXdSruWx7pPFrROppMsZCxp2S1zhRdbYxH/Na3Zl3p6AG0pdhFK5v2DFzd0/Rtrp5t53 tVxLlZ+yMZbtp/Q/sNYl7fel7fI3ZlM= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=eotifFW6; dmarc=none; spf=none (imf05.hostedemail.com: domain of BATV+f852a6472c07d339093a+7456+infradead.org+hch@bombadil.srs.infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=BATV+f852a6472c07d339093a+7456+infradead.org+hch@bombadil.srs.infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1705905559; a=rsa-sha256; cv=none; b=z3oevVD7HSKHlrs55z33Lnh/dwqFTwb9aik9NCoIZDQwowjH3srsAuNXSZ/17jE9KkG7Rt ZJoldGGUl3L8tHSstFZponF6mrT6yz77phVg8CyFLOQAPLR0cZcK17C2P/kt0GMThrCk5G +UgJacdAARWArq7pQQL676xzhbnf7Lc= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=Al8BzeKCJa/SU229J/wH0y+VrQO/ruk7m6AVYzxSD+Y=; b=eotifFW6SEJQTsqAnrzqc5kACn L8GrmggaHMvhHhOlTW/Z1EpymDDkYp40fflc01jzbgpiH4k4DdGfY+8ttMzc+gMHDqNYwvRiBx5a7 E5wh4SQtTPpe8ruwVuCXMZTxuyRKSK6ujxPOs6LtFjVUojZY9pF0Gh664202Msk9StWAPWAN+0uCi 2ID1zRwcTBHtoZr18fW94pOKpvBVKplVqkf3CFimEwvl3G9ZVqwmmVUMnVAPT8fETwFKYlJbThUu+ dIMZoPRmlpo1IK+ooIr7wxStH8+yaK2bL+heU5byB03uXqF+Zz3KBu71FiN99vuehpCdTLR9ID4Rw tFlI977Q==; Received: from hch by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1rRnxg-00AlG0-2Y; Mon, 22 Jan 2024 06:39:12 +0000 Date: Sun, 21 Jan 2024 22:39:12 -0800 From: Christoph Hellwig To: "Darrick J. Wong" Cc: Dave Chinner , linux-xfs@vger.kernel.org, willy@infradead.org, linux-mm@kvack.org Subject: Re: [PATCH 2/3] xfs: use folios in the buffer cache Message-ID: References: <20240118222216.4131379-1-david@fromorbit.com> <20240118222216.4131379-3-david@fromorbit.com> <20240119012624.GQ674499@frogsfrogsfrogs> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240119012624.GQ674499@frogsfrogsfrogs> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 36F4A10001D X-Stat-Signature: ms3phu84e7rdb1t9y7gpn7oc1i76171a X-Rspam-User: X-HE-Tag: 1705905558-409621 X-HE-Meta: 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 uWfvHCgO qPdT4jWSbfNeTr019DYb3oMKSIB5EhYoXwcb2Y7qmFBu1ZtUyBHc16/NDZK70uoGq/5vtbfEz73bXMl7/EGoWUoL6C0HZusYhc6Yy9mWoD6pAzo14kb22/H51cZVm5oJuBJKHqCWJn2/5XMezarLjrBTro59SmPeTtaQpyuudhCfXoTbvbV7sIx8CofizTp9S9WdEwoA6WuXemSPCStnGXSUqr9qIdtLfiKZKvQgk/Wq1wvITUYE/ci0C/SlpQpnolJl7NqcTJcWO7bv4KvHb7lGagojB8GTv0oc9l7nk6NLEfAj7YRPID6m7KpM86eeuhqjAnoZFonB4A65xNcRuwU4e4MIw1I5o4yo4aY8406fFo5geD8j0zfmcGjE9u+UmikYE X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Jan 18, 2024 at 05:26:24PM -0800, Darrick J. Wong wrote: > Ugh, pointer casting. I suppose here is where we might want an > alloc_folio_bulk_array that might give us successively smaller > large-folios until b_page_count is satisfied? (Maybe that's in the next > patch?) > > I guess you'd also need a large-folio capable vm_map_ram. We need to just stop using vm_map_ram, there is no reason to do that even right now. It was needed when we used the page cache to back pagebuf, but these days just sing vmalloc is the right thing for !unmapped buffers that can't use large folios. And I'm seriously wondering if we should bother with unmapped buffers in the long run if we end up normally using larger folios or just consolidate down to: - kmalloc for buffers < PAGE_SIZE - folio for buffers >= PAGE_SIZE - vmalloc if allocation a larger folios is not possible