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 A1FD8CD11C2 for ; Wed, 10 Apr 2024 15:30:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 168CC6B00BC; Wed, 10 Apr 2024 11:30:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1189D6B00BD; Wed, 10 Apr 2024 11:30:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F22966B00BE; Wed, 10 Apr 2024 11:30:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id D39236B00BC for ; Wed, 10 Apr 2024 11:30:28 -0400 (EDT) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 98CBCC0737 for ; Wed, 10 Apr 2024 15:30:28 +0000 (UTC) X-FDA: 81994008936.30.EC9A155 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf10.hostedemail.com (Postfix) with ESMTP id 0D6C6C0017 for ; Wed, 10 Apr 2024 15:30:24 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="ga2UZ/EP"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=B2IeSOD6; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="ga2UZ/EP"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=B2IeSOD6; spf=pass (imf10.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.130 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1712763025; a=rsa-sha256; cv=none; b=vNj5GLIkamwEkCzRPi44/VxP4n5reFXMelnUNElol2XYTAVa/oNGLz+zgO8+7kpLm48RGv AGkB4DZTRsYinxFNWkqZEh5bvyHybCGxlLE/0dBfl/0fOANtxXuopGwscZ8ZfjnBVdv+iX Ed+bOnOBn/VuE7fXLDgKxWprbuE++VM= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="ga2UZ/EP"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=B2IeSOD6; dkim=pass header.d=suse.de header.s=susede2_rsa header.b="ga2UZ/EP"; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=B2IeSOD6; spf=pass (imf10.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.130 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1712763025; 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=RLAgoXFCUgE2afuLi+WthpQqOqP9wv/HKYRh6gvTsc0=; b=Glkah8Qcvxsxvx7tsYD0ehAkGwiMas+Mz8NM1nwtLqlfAtggenL5cRoAdFPWxOz9mFyYfH Mu/bs6NhrX9Cw+Yb38aBiN9DkXs94xdfH801Kx6qW5cIC6Unew3hcR7bLd+hcNHSxhxcxQ xFDPs9w2L0oOHGoUbl7Oo+fh7oBeX+g= Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 54B78371E6; Wed, 10 Apr 2024 15:30:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1712763023; 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=RLAgoXFCUgE2afuLi+WthpQqOqP9wv/HKYRh6gvTsc0=; b=ga2UZ/EPZUiRFWSRVy0PBtATYRsBGbHGOsdnCllSctI0IaMN+1DsLkRwM73ZAKlaa2w3oB HQXwL/XA0GlS11BMz6ajRi140P+T6+99MiBRCVvgy1LI12pQEWKXMZYt8MBE5wzk7gF70l rGatGZVpwnbO9wW4jfF2CPIJA+p2sWs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1712763023; 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=RLAgoXFCUgE2afuLi+WthpQqOqP9wv/HKYRh6gvTsc0=; b=B2IeSOD6G7nn/gGODMRnhpk08YX24vXzNJMvAHYxupRxr+rKt8JeycWzuR7owGjSjUERPo rMObEEsXp6xGO0Bw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1712763023; 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=RLAgoXFCUgE2afuLi+WthpQqOqP9wv/HKYRh6gvTsc0=; b=ga2UZ/EPZUiRFWSRVy0PBtATYRsBGbHGOsdnCllSctI0IaMN+1DsLkRwM73ZAKlaa2w3oB HQXwL/XA0GlS11BMz6ajRi140P+T6+99MiBRCVvgy1LI12pQEWKXMZYt8MBE5wzk7gF70l rGatGZVpwnbO9wW4jfF2CPIJA+p2sWs= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1712763023; 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=RLAgoXFCUgE2afuLi+WthpQqOqP9wv/HKYRh6gvTsc0=; b=B2IeSOD6G7nn/gGODMRnhpk08YX24vXzNJMvAHYxupRxr+rKt8JeycWzuR7owGjSjUERPo rMObEEsXp6xGO0Bw== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 0D53313691; Wed, 10 Apr 2024 15:30:23 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Ec9vAI+wFmaZMwAAD6G6ig (envelope-from ); Wed, 10 Apr 2024 15:30:23 +0000 Date: Wed, 10 Apr 2024 17:30:21 +0200 From: Oscar Salvador To: Matthew Wilcox Cc: Jane Chu , Miaohe Lin , linux-mm@kvack.org Subject: Re: [PATCH v2 07/11] mm/memory-failure: Convert memory_failure() to use a folio Message-ID: References: <20240408194232.118537-1-willy@infradead.org> <20240408194232.118537-8-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 0D6C6C0017 X-Stat-Signature: ibttkct8jriqsiyeikiycedbem9o1sfr X-Rspam-User: X-HE-Tag: 1712763024-621742 X-HE-Meta: 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 bvCFm6zd EDNKbeSO4vSEdGUXEj4JNlrAYWxZTSKQEq6RT0QBbGR9IgdT/1ci3YMitqNMefyxt3weDYrf3SbgvNIErBwD0OLQauxyjEFKXUOXJsrjWFel4AIeZ6YykLDVeAQ8ov6b1VQQiBGY4NegT7a60vPZcqZ8RqwlHE+CnBmPPEnbRavBgPjWxaZWUNFd7992a1sKaDkLYp3pfciN35M3VX2qTmqA0q9tMccc5R5W/cXEI1U1XNz1JAR+WMw8NKut/GOczXhvcwleVXErrt/DDCD3mIDVzuw== 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 Wed, Apr 10, 2024 at 03:23:10PM +0100, Matthew Wilcox wrote: > On Wed, Apr 10, 2024 at 12:21:07PM +0200, Oscar Salvador wrote: > > On Mon, Apr 08, 2024 at 05:34:29PM -0700, Jane Chu wrote: > > > At this stage,  'p' is not expected to be a large page since a _refcount has > > > been taken, right?  So is it reasonable to replace the "if (retry)" block > > > with a VM_BUG_ON warning?  otherwise, if 'p' became part of a different > > > large folio,  how to recover from here ? > > > > We might have split the THP (if it was part of), but AFAICS > > nothing stops the kernel to coallesce this page again into a new THP via e.g: > > madvise(MADV_HUGEPAGE) ? > > Won't that allocate a _new_ THP rather than coalescing in place? Sorry, yes, I think it will. I guess I meant MADV_COLLAPSE. My point is that somehow this page can be used to form a new THP, or is there anything stoping the page to become part of a compound page again? -- Oscar Salvador SUSE Labs