From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 B34712C0F84 for ; Thu, 14 May 2026 15:47:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778773651; cv=none; b=OT8GM+/gqI1BXyfem1DgzD6bRKHDaNp6Dei5cOd0OZ3oex3srdnoubP8tC/6EbRVodcQjqZQvxxOWuRm0ArWk+xAvcL8MCTYhT17DTeq/vVbQ4uJDBmfzyQgF4XqVQM+SKMPhvsMMJlYK2h022Vxi58kJyWGJ57Z/89XiKc8/sM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778773651; c=relaxed/simple; bh=sBS9FZZLijles2p8ZJzPyEoJGKrDkc+L9rT8SXjdOlc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: In-Reply-To:Content-Type:Content-Disposition; b=oXXG+O15d++Qkwyj1ZsJZIghgv7wk1WD9BqtIz+5Ba/tEF/3fIf5MY+fvc0BWktWiglznRlQUGBUwYtMZjrR8IUEF2qJ7ZGTeox9KRfy1f+hqreFYMM6doJCEvSE156LhApVfULani1vQ983qI7jXK2iAM+CgoDUITgRA5W0So4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=Hgzh3q1B; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Hgzh3q1B" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778773648; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=bqdtv1pQkNj5ZtCXeAHZim6ZUYoMn7Cztcf2yOjIZPA=; b=Hgzh3q1B6on+SeLUhaXlg2qaY3n+0tm+2iP++AHO4wQ3wELAaBXmBh1j7Nno2t4yQMho6I dFSlfMezX/n915YPSX+o42HKn/H9f1aVPfcpwqTN24jp+OBSyp2nF/i6T7hPR7qJeE5DjE wAIzN985Bz7SRHWiHG1sP6nICEpS3nc= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-593-8lb1_78rNTqSCQewfMtHiA-1; Thu, 14 May 2026 11:47:27 -0400 X-MC-Unique: 8lb1_78rNTqSCQewfMtHiA-1 X-Mimecast-MFC-AGG-ID: 8lb1_78rNTqSCQewfMtHiA_1778773646 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-4411a36715dso5839527f8f.2 for ; Thu, 14 May 2026 08:47:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778773646; x=1779378446; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=bqdtv1pQkNj5ZtCXeAHZim6ZUYoMn7Cztcf2yOjIZPA=; b=VzgJe3jWWq5n7qMbdVVmMIAHElfVxBtw2adRxv7ZW7ySS2pBUf8jkfnEEKxdQocFWO 1j5gJraMl+TGGg2c23divbeyfo8z5bTMqRpncYwNdfHDiuuPHQFrlSlUfy/MQyChgDfX yt331r7NkpzXPvyXA+5TMTYHxlXCQY9WDBhSy2uvwLxJZgAkJ1xV/0HGTibW67fSiKYL 4xhZFEjknJYRpkv8wJKOGBDnFAMdxedo65e1ekTo9QZGW0QNJTfgUS8QHVwdCCDMox68 NGu98JTB63vcoXvBqy450PA64hO6t4Xoj1dtxfAjeQZ0/EE77ZLGLl/cHb439KP8qexo 6izg== X-Forwarded-Encrypted: i=1; AFNElJ9Mc4YY4ylzpSwV6spuONzo11ZrF7PlZ0wrMmjhR5awFNbJK76c/lClsBns//vz/SIJv0WpN4tWxNQ0OaqClQ==@lists.linux.dev X-Gm-Message-State: AOJu0YyX5MjS920ATajiGexStkWhEOFB9ahEJgVRS6q7+zXxuLj9+y3G pPYatd61covhrePiHsV6FFzlMtckG6nzlZquEeBK8mbyh+yLcFenqkrnyXoXD/O3grZpO/tA2bu SjA51rZ0ZfOLps81I3SvMfec9k9ESPfKnjns9uUbAd/VHSC3pXkyrKg20UfegH7BZv/9Q X-Gm-Gg: Acq92OHqFL1GU3RRXtRFb7qQgkmph5mKMDdxmcjAyVQ/eHeZ2l+IU8DU2s6IF7S2I4w 80iqEnXfwqGKi7jGZD8tCh0RKVxAoBPwP/rGAKliU4Vz4/0uDOMvBT9eUouqVRlfY1aF+oVH4zK 5wysZ7Ooy+z+KK07J9fupxCNU+V61s4qxIJan/woAGS7a5PJUEXP6Z0zttoVevADhJ1lhSlwmjg WdAbJoK7SaZqFfSUHXTbrwkN2eHLThgmxER4QeGYLe7n7QimZk3NIZY63Ntrc8LDL+AyP4ge5VW 46jJBmLBoRg2QOoIjoV820p9daCg6kbyvLj8ogCXkr5xYKZvDaQpAam9joRLvt1KJflr1lmRKQ9 fDd8HscPsTUBi0a6sfVUjijRXa486GxHjPXQ+pxd1 X-Received: by 2002:a5d:5f45:0:b0:449:a07a:967f with SMTP id ffacd0b85a97d-45c5a1a8e93mr14113755f8f.28.1778773645902; Thu, 14 May 2026 08:47:25 -0700 (PDT) X-Received: by 2002:a5d:5f45:0:b0:449:a07a:967f with SMTP id ffacd0b85a97d-45c5a1a8e93mr14113648f8f.28.1778773645241; Thu, 14 May 2026 08:47:25 -0700 (PDT) Received: from redhat.com (IGLD-80-230-48-7.inter.net.il. [80.230.48.7]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-45d9ed2f738sm7555351f8f.16.2026.05.14.08.47.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 May 2026 08:47:24 -0700 (PDT) Date: Thu, 14 May 2026 11:47:19 -0400 From: "Michael S. Tsirkin" To: Gregory Price Cc: linux-kernel@vger.kernel.org, "David Hildenbrand (Arm)" , Jason Wang , Xuan Zhuo , Eugenio =?iso-8859-1?Q?P=E9rez?= , Muchun Song , Oscar Salvador , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Hugh Dickins , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Ying Huang , Alistair Popple , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , Axel Rasmussen , Yuanchu Xie , Wei Xu , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , virtualization@lists.linux.dev, linux-mm@kvack.org, Andrea Arcangeli Subject: Re: [PATCH v7 02/31] mm: page_alloc: propagate PageReported flag across buddy splits Message-ID: <20260514114637-mutt-send-email-mst@kernel.org> References: <20260514104735-mutt-send-email-mst@kernel.org> <20260514113337-mutt-send-email-mst@kernel.org> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: bMM-KHkYmMkfExGN2cpsph_oRnHCmF0LuZT-tlaT7IM_1778773646 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, May 14, 2026 at 11:41:45AM -0400, Gregory Price wrote: > On Thu, May 14, 2026 at 11:34:14AM -0400, Michael S. Tsirkin wrote: > > On Thu, May 14, 2026 at 11:32:26AM -0400, Gregory Price wrote: > > > > > > > > > > Maybe mildly out of scope but worth asking: Are there other flags that > > > > > should be retained/propogated on a split? If so, rather than pass > > > > > was_reported, should we just take a temporary copy of the page flags and > > > > > pass them all in? > > > > > > > > > > ~Gregory > > > > > > > > > > > > Not that I can see, no. > > > > > > > > > > You do this exact thing again later :] > > > > > > https://lore.kernel.org/linux-mm/9a22e0f9bbe1278913754db6df76e291a006181a.1778616612.git.mst@redhat.com/ > > > > > > ~Gregory > > > > I mean yes, reported and zeroed) Just zeroed does not exist at this > > stage in the series. > > > > More of a forward looking question: if we already know we're adding > was_reported and was_zeroed, maybe we should just pass the page flags > through entirely and let expand() check them instead of passing it > through individually. > > We end up doing something similar with post_alloc_hook later as well, so > I'm wondering if there's a general improvement that can be made here. > > ~Gregory sure, will do. do you want a bitwise thing for type safety? or just a long?