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 B21BFC83F17 for ; Thu, 10 Jul 2025 18:20:11 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 220626B0095; Thu, 10 Jul 2025 14:20:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1D0896B0099; Thu, 10 Jul 2025 14:20:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 099F66B009A; Thu, 10 Jul 2025 14:20:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id EC8EA6B0095 for ; Thu, 10 Jul 2025 14:20:10 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id A746116095B for ; Thu, 10 Jul 2025 18:20:10 +0000 (UTC) X-FDA: 83649169380.01.F790BEC Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) by imf14.hostedemail.com (Postfix) with ESMTP id B0E73100014 for ; Thu, 10 Jul 2025 18:20:08 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=07OW4xAD; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf14.hostedemail.com: domain of almasrymina@google.com designates 209.85.214.181 as permitted sender) smtp.mailfrom=almasrymina@google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1752171608; 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:dkim-signature; bh=Vj46vkefhs4SRIRS/QU5g/lyrMXzFbGQlucGo0/msd8=; b=WMTh7vK/ZSw4f+SEYS9tAv8GyG+Ig7qgPwY4pOM9GGE16RcE4+Q2XKHHxGq6ETyFtO+J1F XMQ+uo+CqnlcIpYY4GWs5d8bjDXe8HDhwfXH8l1u10Uyc9lrRS6MZsDCdF0mMYfPtRlq9B 99nr6XRQR3yRq82eGjTqdyMHkfVis/8= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1752171608; a=rsa-sha256; cv=none; b=KFMRQP8UEbFv4Xh/qNt7zpkuyV2VjZNWQufr1LbgqfXBxWWL6ADQ6EYtNpAgun2rXUHbVF RzycSXG4xjobXX+vny88NMpM3RAqLvtkXAIfTSiXHdV53ADJsd9UuWX5uxnwk9wfIWdl/9 47Jip+GTe70xQEkLTJKhDdJwVqsmrLU= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=07OW4xAD; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf14.hostedemail.com: domain of almasrymina@google.com designates 209.85.214.181 as permitted sender) smtp.mailfrom=almasrymina@google.com Received: by mail-pl1-f181.google.com with SMTP id d9443c01a7336-2357c61cda7so23075ad.1 for ; Thu, 10 Jul 2025 11:20:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1752171607; x=1752776407; darn=kvack.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=Vj46vkefhs4SRIRS/QU5g/lyrMXzFbGQlucGo0/msd8=; b=07OW4xAD04SabfQWHYjQ38vCL2NUP/sBW8v8NOVgMG0/GtIfB0xFw8N+doOt2BdaDr r+rnHgXdM0a77LZZJHUEQ8pP41c95ZsicMBfasiVUH8b8QQvtyVWpBzSTdWgSmGxBVH5 mpaVJxr0M2FFk36XdNlNvzlXyl1trELshpdtKotZyh99pYpXBp/sk6dP4SzoXEILXiQO LZmKqwGwRSEWrrcS8aMAgnqS5/YjSV3Xue0OgTPXuNNkuHduUmYJTK1w55od/e9DRrn8 1XTTV3ZuSUH3Xm68WVZOqKOZLW2IV76nNAst/YbzUV7sozdKHtI+OEOBMe9EeVsY2Asv soTw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752171607; x=1752776407; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Vj46vkefhs4SRIRS/QU5g/lyrMXzFbGQlucGo0/msd8=; b=mI4No2ndnlYeOxQ4czbaxw2vEq43Q9d7QZsdBMnS2Z55vgunL0Cz5PZLrZJpo0RZdu G/v2xr9iAe4AeIDdOs5VBWF1Q5sQkGCYSG8DU2TwD+DNIJyttU3DQ6r+5EU+L+IObnhy 3UUKrFjHiOnm2OjCz2vsOOOG5uzjc7mXq39OmidAY74lFf38zmqv3xZ2XvkNjTVRKkd+ 4GXiMaZ5zu87Lxyj+SehL0hBxtDxHbUySklKuVleMjvN0WKasMI/OlCdD7UgCskuWdYm B42K4GQtsd0OGOc8GCnlzgxWn9CXVJhi7jGky+NKC22u0uKw3iiy2on5lVbLM39yPBe7 lTIA== X-Forwarded-Encrypted: i=1; AJvYcCUb+u8TznibDEjbko4MJBr1LqWN6QG7iumtg0vIvvUX1fKo70Hk1fCU+zdElZViq1dGPNsYTp3l0Q==@kvack.org X-Gm-Message-State: AOJu0YyYpSCxNWZ/NwU/GFm058YKUMcl0Q4bC79cDO7cRBieOECtyPvC d/wXrbG5PrjpQBwRnvlNZcKL9+ZS3CWbl4gS5m1JYdXh8JBxgMVWCuRhqLWkG8EOqX2+t2486J8 apcZSFwqyFj/jOBTQrjT96U7TsKPOsGojwqgYk0pO X-Gm-Gg: ASbGncuW4mHIkJiPwvuoBfnRu0PvCpwRNGHmbrChP8RxiNanymV9crXmDoHbG1RGNWW 1afsPbmZ9L8His/JvOBFLeV3nvcN5m+E2bSHguB8EaMdRF+sAUPilUKWPUIR8FhScfTD/uFt/ns 4/F+aQorCWWfKowJP8gN0jAZThvSnKoeXb+bUJDU0RuowFB7SHBo0mpMscDGQtdgZbeFq6XC4= X-Google-Smtp-Source: AGHT+IEnsQr2vt1xRK9+Gg05s9Ioj58hP/Frug0vVmNYyI/waR29AKDxjbFsuLIHKriJNaWLDKD8Qv90dKQTUZAuhEc= X-Received: by 2002:a17:902:d4c1:b0:234:bfa1:da3e with SMTP id d9443c01a7336-23dee4c480fmr119455ad.5.1752171605810; Thu, 10 Jul 2025 11:20:05 -0700 (PDT) MIME-Version: 1.0 References: <20250710082807.27402-1-byungchul@sk.com> <20250710082807.27402-4-byungchul@sk.com> In-Reply-To: <20250710082807.27402-4-byungchul@sk.com> From: Mina Almasry Date: Thu, 10 Jul 2025 11:19:53 -0700 X-Gm-Features: Ac12FXw53iJ9LLYfmK6k3qWagqoxpTOfsxU_34s2pmiydSWa2zOUfuaE-4Qlaes Message-ID: Subject: Re: [PATCH net-next v9 3/8] page_pool: access ->pp_magic through struct netmem_desc in page_pool_page_is_pp() To: Byungchul Park Cc: willy@infradead.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel_team@skhynix.com, kuba@kernel.org, ilias.apalodimas@linaro.org, harry.yoo@oracle.com, hawk@kernel.org, akpm@linux-foundation.org, davem@davemloft.net, john.fastabend@gmail.com, andrew+netdev@lunn.ch, asml.silence@gmail.com, toke@redhat.com, tariqt@nvidia.com, edumazet@google.com, pabeni@redhat.com, saeedm@nvidia.com, leon@kernel.org, ast@kernel.org, daniel@iogearbox.net, 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, linux-rdma@vger.kernel.org, bpf@vger.kernel.org, vishal.moola@gmail.com, hannes@cmpxchg.org, ziy@nvidia.com, jackmanb@google.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam02 X-Rspam-User: X-Stat-Signature: prntk5rppqmpwx14kqk38ihkrc8q9e5c X-Rspamd-Queue-Id: B0E73100014 X-HE-Tag: 1752171608-572802 X-HE-Meta: U2FsdGVkX1/u+62I9nAvDpE3hkM3//9feOLoQ5asEnM0c4Nm/2VkSIcR6/InlpLCted/1Cm2c/iLMwEy5e0y1xyQxDQRM/fB2SK+BCLlbvuw66GOw+0x55ZAfhfg5tNKfjLFhexKWGz7NCDznKlQqaXUN8KHKTzyC6wnULN2AFXJF51PPkKAeMCq+eEAPVuUu8a1vYoUUE+nWP5Ee3W+3yIzlI5NWFn22XXIuTi9qhqyS4a9p8Q4e97M8gXsLrRlc2nAa8plPZaMTX/mFZRGPx+Rtn6467GTghx7mpStaHnCSRFZfA2LLL00Nu5pKb5oszkssd6WJSINVHSlpmWWf7vevuOuj7hXFwOFoa0m77klJU4smFjjd5Rn6P5l3SzZ/YNAqMsXQZl2JG4eOWvGXBCxvGkReL6gZJfQ+7CkDdFjKRLSJgN5qWgaV2dGNPgms9VHmHqGMwalWw6uUeLJrhwYaKM0Zb3gfGpxfl/rCHYBk13Xe1Kq8lhB3Lkq6SUd/M2PXCacpBVJr6zvvxzwk9SvqoloxlfHvUgz+o4F86XL//nqa5I+dKzSNvaNkuw+LV4UcYmn9UAToZjKLfPXWxXDbkP69IHRAf11KKvhPYEEu3ie7oKVCTltb8kUJ7ETm21TiN/nGynkDOn8Os9v6eTFTJFxfgHnwTPj/Xwu8y5x84Ci/oXI2d/a++/exVS1hFT7Krx8IKXzi0fBKDUzRjt6IgatWvIQ2PBlv43oHnBMj7z9UjRBgkihoh8uBETqx5vhImS/3ChB1pPRmWH835JJ4GQcaIdXkN/JfttusTBqpgvPrng2sz7pE7F99CHCGW1WMWmWtmklzgS40OlXA9P5O9PzxrZYlkQyjUZ7saxMgHOMoBwIxrpP+SDS7WMXyIEDaGl7Z9YjDUwQ9agzYjJzMqtepXvsLHgXl8XJQwVr+7fi8sXAggZCbp17WryFjEajmvjj8DuTGJz+fW7 54RwK+eE 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 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, Jul 10, 2025 at 1:28=E2=80=AFAM Byungchul Park w= rote: > > To simplify struct page, the effort to separate its own descriptor from > struct page is required and the work for page pool is on going. > > To achieve that, all the code should avoid directly accessing page pool > members of struct page. > > Access ->pp_magic through struct netmem_desc instead of directly > accessing it through struct page in page_pool_page_is_pp(). Plus, move > page_pool_page_is_pp() from mm.h to netmem.h to use struct netmem_desc > without header dependency issue. > > Signed-off-by: Byungchul Park > Reviewed-by: Toke H=C3=B8iland-J=C3=B8rgensen > Reviewed-by: Mina Almasry > Reviewed-by: Pavel Begunkov > Reviewed-by: Vlastimil Babka > Acked-by: Harry Yoo > --- > include/linux/mm.h | 12 ------------ > include/net/netmem.h | 17 +++++++++++++++++ > mm/page_alloc.c | 1 + > 3 files changed, 18 insertions(+), 12 deletions(-) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 0ef2ba0c667a..0b7f7f998085 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -4172,16 +4172,4 @@ int arch_lock_shadow_stack_status(struct task_stru= ct *t, unsigned long status); > */ > #define PP_MAGIC_MASK ~(PP_DMA_INDEX_MASK | 0x3UL) > > -#ifdef CONFIG_PAGE_POOL > -static inline bool page_pool_page_is_pp(struct page *page) > -{ > - return (page->pp_magic & PP_MAGIC_MASK) =3D=3D PP_SIGNATURE; > -} > -#else > -static inline bool page_pool_page_is_pp(struct page *page) > -{ > - return false; > -} > -#endif > - > #endif /* _LINUX_MM_H */ > diff --git a/include/net/netmem.h b/include/net/netmem.h > index ad9444be229a..11e9de45efcb 100644 > --- a/include/net/netmem.h > +++ b/include/net/netmem.h > @@ -355,6 +355,23 @@ static inline void *nmdesc_address(struct netmem_des= c *nmdesc) > return page_address(nmdesc_to_page(nmdesc)); > } > > +#ifdef CONFIG_PAGE_POOL > +/* XXX: This would better be moved to mm, once mm gets its way to > + * identify the type of page for page pool. > + */ > +static inline bool page_pool_page_is_pp(struct page *page) > +{ > + struct netmem_desc *desc =3D page_to_nmdesc(page); > + > + return (desc->pp_magic & PP_MAGIC_MASK) =3D=3D PP_SIGNATURE; > +} pages can be pp pages (where they have pp fields inside of them) or non-pp pages (where they don't have pp fields inside them, because they were never allocated from the page_pool). Casting a page to a netmem_desc, and then checking if the page was a pp page doesn't makes sense to me on a fundamental level. The netmem_desc is only valid if the page was a pp page in the first place. Maybe page_to_nmdesc should reject the cast if the page is not a pp page or something. --=20 Thanks, Mina