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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B3FC4C433FE for ; Mon, 27 Sep 2021 18:54:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9565660FD7 for ; Mon, 27 Sep 2021 18:54:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235866AbhI0Szi (ORCPT ); Mon, 27 Sep 2021 14:55:38 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:60960 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235804AbhI0Szg (ORCPT ); Mon, 27 Sep 2021 14:55:36 -0400 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 3B9511FF71; Mon, 27 Sep 2021 18:53:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1632768837; h=from:from:reply-to: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=i8YFrJJL3ygDjTHfhpq/hMFm7t3mtPppxrHwThWiRyE=; b=Ye7n1C/Gtiaw0lIGnDPPVjtS2+5wNp0fzQmY/qzeSw29Jz0vJLCx3BpQ09/Mj02MxM2bvj 3oqwKnjSrXl8o/sXq2prfyd6MoHeiqz8WnffQ8C0a54znwnnFUN9laIi1omboDqV+3fW2u 6T9ZcBcyNW0cN8uSekz6pNJphQLMoAs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1632768837; h=from:from:reply-to: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=i8YFrJJL3ygDjTHfhpq/hMFm7t3mtPppxrHwThWiRyE=; b=HzQWu9YFVJihCFVRftrGHi4rgdEJv5g5cGIdHYYwFULRH3DRXpIvstpZUIJ81ovtmmL7Pf Ds9xg/jp8pvZ4SCA== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 7900613BF2; Mon, 27 Sep 2021 18:53:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id WHTIG0ATUmHXNwAAMHmgww (envelope-from ); Mon, 27 Sep 2021 18:53:52 +0000 Message-ID: Date: Mon, 27 Sep 2021 20:53:48 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.1.0 Subject: Re: Struct page proposal Content-Language: en-US To: David Hildenbrand , Matthew Wilcox , Kent Overstreet Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Johannes Weiner , Linus Torvalds , Andrew Morton , "Darrick J. Wong" , Christoph Hellwig , David Howells References: From: Vlastimil Babka In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/27/2021 8:16 PM, David Hildenbrand wrote: > On 27.09.21 20:12, Matthew Wilcox wrote: >> >> But the thing we're allocating is at least PAGE_SIZE bytes in size. >> Why is "We should avoid storing anything in the free page itself" true? >> > > Immediately comes to mind: > * Free page reporting via virtio-balloon > * CMA on s390x (see arch_free_page()) > * Free page poisoning > * init_on_free I was thinking of debug_pagealloc (unmaps free pages from direct map) but yeah, the list is longer.