From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C08C3283FE8 for ; Fri, 6 Jun 2025 08:27:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749198436; cv=none; b=HtxaC2xuBtmK2Gl2iWxhFkW5b5P1TUYG3pvE+mafT7GN8KL2KNRAilgz/hd3Isdyn4pFabzm9JSrF15w+JyanYVbHAJ0oYhE41d3wFEtKdkpnpwmA8kZl0tFUHI5pdlosxSa93RLH3eoAF6qVI1DDugyWK0k1M6Pgf44MrZj7tE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749198436; c=relaxed/simple; bh=GUe49uEBje2seW3kBTDoZdmBDgc00U9icBdzKvpEZpk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aR0HkPNzHj/eCpIREQEp7wE7/trdVr4lz2DNtnXXKfQ9JL3j+JbJy8f6v0cDvCzNIntMt9Byb67+jGRThmyHBO7wfGQtIj0uip33GGLaBaeslKRhGJHAXYyPpNrSyAze77y1yYZRIu7z7g2G8RPcm3jRGvnNF2zYghYY1azYogA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=wO3P6wlX; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=97BLMfZJ; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=wO3P6wlX; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=97BLMfZJ; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="wO3P6wlX"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="97BLMfZJ"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="wO3P6wlX"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="97BLMfZJ" Received: from imap1.dmz-prg2.suse.org (unknown [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-out2.suse.de (Postfix) with ESMTPS id F202E1F46E; Fri, 6 Jun 2025 08:27:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1749198432; h=from:from:reply-to: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=AbHdt3R0Dg9obxm/5Tz1H6QEtuLCv5Q1f/9X9tztXsM=; b=wO3P6wlXjt+W2MXDO5dpFJQtBoEA+cO0kTABzo8wu0ZgsP/GIND4cEv9ird8Jj3G8dfomz 0apDkoEosXdlMJ2mO5i7mrUL9GnYJW5IqmKRwDyENFT/OwpIxt5NBae9DUe8WuxUhVmEji WIb+diNAClLe+73zzJUpkfbtp+bmNjo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1749198432; h=from:from:reply-to: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=AbHdt3R0Dg9obxm/5Tz1H6QEtuLCv5Q1f/9X9tztXsM=; b=97BLMfZJ9qD0GtqMNCwjkDm9sNoMwU91m0fym1mB+cyV4t8UjT2cKTAwWqQyv6JCtK13qN dXD9J2eP/h35eYCw== Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1749198432; h=from:from:reply-to: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=AbHdt3R0Dg9obxm/5Tz1H6QEtuLCv5Q1f/9X9tztXsM=; b=wO3P6wlXjt+W2MXDO5dpFJQtBoEA+cO0kTABzo8wu0ZgsP/GIND4cEv9ird8Jj3G8dfomz 0apDkoEosXdlMJ2mO5i7mrUL9GnYJW5IqmKRwDyENFT/OwpIxt5NBae9DUe8WuxUhVmEji WIb+diNAClLe+73zzJUpkfbtp+bmNjo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1749198432; h=from:from:reply-to: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=AbHdt3R0Dg9obxm/5Tz1H6QEtuLCv5Q1f/9X9tztXsM=; b=97BLMfZJ9qD0GtqMNCwjkDm9sNoMwU91m0fym1mB+cyV4t8UjT2cKTAwWqQyv6JCtK13qN dXD9J2eP/h35eYCw== 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 E88001369F; Fri, 6 Jun 2025 08:27:10 +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 zkcMNl6mQmhgBgAAD6G6ig (envelope-from ); Fri, 06 Jun 2025 08:27:10 +0000 Date: Fri, 6 Jun 2025 10:27:09 +0200 From: Oscar Salvador To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, Andrew Morton , Alistair Popple , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Dan Williams Subject: Re: [PATCH v1 1/2] mm/huge_memory: don't mark refcounted pages special in vmf_insert_folio_pmd() Message-ID: References: <20250603211634.2925015-1-david@redhat.com> <20250603211634.2925015-2-david@redhat.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250603211634.2925015-2-david@redhat.com> X-Spamd-Result: default: False [-4.30 / 50.00]; BAYES_HAM(-3.00)[99.99%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; MISSING_XM_UA(0.00)[]; RCPT_COUNT_TWELVE(0.00)[19]; RCVD_TLS_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:helo] X-Spam-Level: X-Spam-Flag: NO X-Spam-Score: -4.30 On Tue, Jun 03, 2025 at 11:16:33PM +0200, David Hildenbrand wrote: > Marking PMDs that map a "normal" refcounted folios as special is > against our rules documented for vm_normal_page(). > > Fortunately, there are not that many pmd_special() check that can be > mislead, and most vm_normal_page_pmd()/vm_normal_folio_pmd() users that > would get this wrong right now are rather harmless: e.g., none so far > bases decisions whether to grab a folio reference on that decision. > > Well, and GUP-fast will fallback to GUP-slow. All in all, so far no big > implications as it seems. > > Getting this right will get more important as we use > folio_normal_page_pmd() in more places. > > Fix it by just inlining the relevant code, making the whole > pmd_none() handling cleaner. We can now use folio_mk_pmd(). > > While at it, make sure that a pmd that is not-none is actually present > before comparing PFNs. > > Fixes: 6c88f72691f8 ("mm/huge_memory: add vmf_insert_folio_pmd()") > Signed-off-by: David Hildenbrand Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE Labs