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 36EABC83F26 for ; Tue, 29 Jul 2025 01:09:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CA2A56B007B; Mon, 28 Jul 2025 21:09:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C540A6B0088; Mon, 28 Jul 2025 21:09:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B41BC6B0089; Mon, 28 Jul 2025 21:09:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id A0ECA6B007B for ; Mon, 28 Jul 2025 21:09:24 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 549A214042B for ; Tue, 29 Jul 2025 01:09:24 +0000 (UTC) X-FDA: 83715519048.25.A78931F Received: from invmail4.hynix.com (exvmail4.hynix.com [166.125.252.92]) by imf16.hostedemail.com (Postfix) with ESMTP id 9D20D180007 for ; Tue, 29 Jul 2025 01:09:21 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; spf=pass (imf16.hostedemail.com: domain of byungchul@sk.com designates 166.125.252.92 as permitted sender) smtp.mailfrom=byungchul@sk.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1753751362; a=rsa-sha256; cv=none; b=e04N1WUDMGmGys/wpCh8Umj6UBtYCROa25OhKiheloEeYBnubyig0Bws7aeowwJE5lljd4 gWyBxSOh5jAxcI+iRsaO15rvYq/gSbW39UrzFQEfuAvTNy8Lzv5FaJi++7+qNYnmwt+14q mU82eUf/cS7A6lzgSANk4Gr9I/EEN08= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf16.hostedemail.com: domain of byungchul@sk.com designates 166.125.252.92 as permitted sender) smtp.mailfrom=byungchul@sk.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1753751362; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=gEqcXYyy5ek8hWBx7PKZf+VNiZvCQg5oXkLdHiZ7dWI=; b=elyXP6Eg4ucz7H9FzHrO9jqrrQiPULD09nXhC7c8SSPq7hpYnd2GCpytwrRn4NOKGcNU2g 1k7Urs5nS5Tj2uI0F/xmWNcO579vHnw3Gn5P+50Q2HWg20De+6AaHeS3a/+kO0s5WGtnRe 7Su6um1TI8yAGkrJt5Pb3cDBQ5c2qeU= X-AuditID: a67dfc5b-681ff7000002311f-05-68881e0fb1f4 Date: Tue, 29 Jul 2025 10:04:10 +0900 From: Byungchul Park To: Pavel Begunkov Cc: Mina Almasry , linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel_team@skhynix.com, harry.yoo@oracle.com, ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net, kuba@kernel.org, hawk@kernel.org, john.fastabend@gmail.com, sdf@fomichev.me, saeedm@nvidia.com, leon@kernel.org, tariqt@nvidia.com, mbloch@nvidia.com, andrew+netdev@lunn.ch, edumazet@google.com, pabeni@redhat.com, akpm@linux-foundation.org, david@redhat.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, rppt@kernel.org, surenb@google.com, mhocko@suse.com, horms@kernel.org, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, ilias.apalodimas@linaro.org, willy@infradead.org, brauner@kernel.org, kas@kernel.org, yuzhao@google.com, usamaarif642@gmail.com, baolin.wang@linux.alibaba.com, toke@redhat.com, bpf@vger.kernel.org, linux-rdma@vger.kernel.org Subject: Re: [PATCH v2] mm, page_pool: introduce a new page type for page pool in page type Message-ID: <20250729010410.GC56089@system.software.com> References: <20250728052742.81294-1-byungchul@sk.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) X-Brightmail-Tracker: H4sIAAAAAAAAA02Se0hTYRjG+fadnXMcGx2X1ZcGwSoKK7sZvd2FCL7+CKIiKimdeWgjN23L WxCsklzS7E41V6yrt9CYTrdKq2leKszMalnN0gyqaaYmmtJlSuR/D8/7Ps/v/ePlsfKJNJTX 6veJBr06QcXKGFmn/MrcqKlmzfzCIh5sxTdZKBxIg9z3LinYCsoQ9A2+4eB3RQ2C3upaFr5W 9SC4erkfg+1pBgM/in9i6Khp46DQsR5ab3xi4G5mOYa243UsWDKGMFQMdnFwyJUnAVuJiYPG smwpnPl5HUO56T0Hz2/bWPDd/C2FTx4LA/XWfAa6z1ZjaM2Oghr7ROh/7EdQXVwugf5jF1l4 ceG2BE432Vloz2hF0FTVxsDZYTMLOQezEQwN/G3rOtEnhZyHPi4qnFb5v2Famv9aQr2VjyTU bX3HUbsjmZbkhdMsbxOmjoKjLHX0nOLo25d3WVp3foih7g9LqdvVK6GWw10s/d7RwtBvlS/Y DeO3y1bEiwnaFNEwb1WsTHPN1oKTLgenHTRtNaHP8iwUxBMhknR21EuzED+in91RBWxGmEFK T/q4gGaFmcTrHcQBHSLMJl9feUZ8LFzlyCVfaCA6XthBbt1bHrAVAhBnpp/NQjJeKbQh4vxw Do8Ogkn9hY/MaHYmGb7UhANZLISR3F/8qD2VHHbmjKwHCSvJvc6GEdQEYRq5X1YrCXQSwc8T 93GXdPT8yeRBnpc5gYKtYxDWMQjrf4R1DMKOmAKk1OpTdGptQmSEJl2vTYvYlahzoL8/duPA cLQL9TRu8iCBRyq5QnM0U6OUqlOM6ToPIjxWhSiSrh/RKBXx6vT9oiExxpCcIBo9KIxnVJMU C/tT45XCbvU+cY8oJomGf1MJHxRqQlfOtXq2RKNVO0tjYsmSrQfOGLTr/C1F5m5z5LLzubO+ x22bXueWR5sXJes25y9wr16stMylMX3+qF2xDRsLyn2vS1KNAxGKZiZsXu/CWrtuy9rUVw1r dhO1fm9qtzOZzpHHPdieZAlZMeWx/JY8DoaNXzLtRbi5tn2Ts3FcRruKMWrUC8Kxwaj+A1Z8 W4FfAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA02SbUhTcRjF++9/d+91trquVRfNglUISpZQ8ITa64f+RUnUhywKveatDafJ pqJBMFOyJM1ezJxTNFPzhazp1JllTFNX0MvEMis1UykyzTTJlKwpkd8O5zzn93w5LFbckbqz mqgYURclaFW0jJIF+SetW7zyvHrDWDIDpsoKGsp/xkNJb50UTGU1CMYn3zIw86AFwVhzKw1f mr4jKCyYwGB6nkzBj8pfGAZa+hgoN++DnuJBChpSajH0XWqjIS15CsODyWEGztbdloCpysBA U65dCi9q0qVw7VcRhlpDLwPt9SYauitmpDBoS6PAbiyl4FtmM4ae9G3Qkr8MJp4OIWiurJXA xMVcGjqy6yVw1ZFPw8fkHgSOpj4KMqfP05CTmI5g6udf2nDGuBRyHncz23xI09AIJtWlbySk 8+ETCbEa3zMk3xxLqm57k9ROBybmsgs0MX+/wpB3rxpo0nZjiiLWD5uJtW5MQtKShmkyOtBF kZGHHfR+5RFZQLio1cSJuvVbQmXqW6YuHF3gFp9oCDagzwtTEcvy3Eb+5X1VKnJhKW4tX325 m3FqmvPiOzsnsVMrOR/+y2vbrI+5QobP63Z3Vpdwx/i7jf5OW84Bb0kZolORjFVwfYi3fMjC c4Ebb8/up+a6Xvx0ngM7u5jz4Et+s3P2Kj7JkjN77sIF8o1fn82+Wsqt5h/VtEoy0CLjPJJx Hsn4n2ScR8pHVBlSaqLiIgWNdpOvPkKdEKWJ9z1+KtKM/q6o+Mz05To03r7LhjgWqRbK1RdS 1AqpEKdPiLQhnsUqpTy66JxaIQ8XEk6LulMhulitqLchD5ZSLZfvOSSGKriTQowYIYrRou5f KmFd3A2o9VOaSnC94Tq5prQ+cve5PR8/b5db7nr6p99bfszuvT/pemDwgsBvJ+lRVOw5EbPC 33LaviPFb9eLWFJ4lBv/6jq9M9RSrY0LSvyddbCW9TiwNSbTb2w0I6T95czZfnZksVVpL7L6 7pC77T0shJWvXR1wYupefcnNyg4HExaQ7fJYRenVgp831umFP0DnRSdBAwAA X-CFilter-Loop: Reflected X-Stat-Signature: 5b99nuqkhs1bz1mhongu5qr4nb6ht7bw X-Rspam-User: X-Rspamd-Queue-Id: 9D20D180007 X-Rspamd-Server: rspam02 X-HE-Tag: 1753751361-207929 X-HE-Meta: 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 8gXzf/3b 9IA0EMYv7utQ30T5xoOS6eiKZZHnWgIKWpVYJGUjOI4DppYqIXB5B8PFUzpaI4z9CGuPRLa2AR6UOj/5Lp6iINaj6wioQQZEWBFGEYw+2drOlCfet8jhuJdK2As4LbcxDrdeah80EVaND/C8= 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 Mon, Jul 28, 2025 at 07:49:30PM +0100, Pavel Begunkov wrote: > On 7/28/25 19:39, Mina Almasry wrote: > > On Mon, Jul 28, 2025 at 11:35 AM Pavel Begunkov wrote: > > > > > > On 7/28/25 06:27, Byungchul Park wrote: > > > > Changes from v1: > > > > 1. Rebase on linux-next. > > > > > > net-next is closed, looks like until August 11. > > > > > > > 2. Initialize net_iov->pp = NULL when allocating net_iov in > > > > net_devmem_bind_dmabuf() and io_zcrx_create_area(). > > > > 3. Use ->pp for net_iov to identify if it's pp rather than > > > > always consider net_iov as pp. > > > > 4. Add Suggested-by: David Hildenbrand . > > > > > > Oops, looks you killed my suggested-by tag now. Since it's still > > > pretty much my diff spliced with David's suggestions, maybe > > > Co-developed-by sounds more appropriate. Even more so goes for > > > the second patch getting rid of __netmem_clear_lsb(). > > > > > > Looks fine, just one comment below. > > > > > > ...> diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c > > > > index 100b75ab1e64..34634552cf74 100644 > > > > --- a/io_uring/zcrx.c > > > > +++ b/io_uring/zcrx.c > > > > @@ -444,6 +444,7 @@ static int io_zcrx_create_area(struct io_zcrx_ifq *ifq, > > > > area->freelist[i] = i; > > > > atomic_set(&area->user_refs[i], 0); > > > > niov->type = NET_IOV_IOURING; > > > > + niov->pp = NULL; > > > > > > It's zero initialised, you don't need it. > > > > > > > This may be my bad since I said we should check if it's 0 initialized. > > > > It looks like on the devmem side as well we kvmalloc_array the niovs, > > and if I'm checking through the helpers right, kvmalloc_array does > > 0-initialize indeed. > > I wouldn't rely on that, it's just for zcrx I do: > > kvmalloc_array(..., GFP_KERNEL | __GFP_ZERO); For net_devmem_bind_dmabuf(), __GFP_ZERO will add bigger overhead than just assignment, 'niov->pp = NULL'. I'd like to ask you if you are still good with __GFP_ZERO overhead before going ahead. Byungchul > > -- > Pavel Begunkov