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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C96CEC43334 for ; Mon, 11 Jul 2022 12:02:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231171AbiGKMCH (ORCPT ); Mon, 11 Jul 2022 08:02:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231138AbiGKMCA (ORCPT ); Mon, 11 Jul 2022 08:02:00 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D0FA23AB0F for ; Mon, 11 Jul 2022 05:01:58 -0700 (PDT) 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 377F91FB37; Mon, 11 Jul 2022 12:01:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1657540917; 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=Nl3HBfd9iKeyfHwCwNnxaKOT8wpVtevnrthm2sJIei4=; b=h1qzbPDa2S5oID8qiFthvAuoEIsUBadp2kYRvz8/OPs9HFCFGEVUVZH5t3XwSOeOWzrLVo sgkiPjeTrLv6SIxE4Koy/0rYajWboEL6eZm+PSemZFYywWbS6TUIteb34srndisLjXGpW4 I/K98HNFJlwN4IyyHKR7ay6Isu+uUpk= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1657540917; 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=Nl3HBfd9iKeyfHwCwNnxaKOT8wpVtevnrthm2sJIei4=; b=XkAJn5gVOwdRlc+aACgY7HstNnfxHTv4TCIiv2sHPPNTVAVwdezQP0tNYDzSQwM6wu9GG+ D7r4WzOedVt1KTDQ== 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 06C9813524; Mon, 11 Jul 2022 12:01:57 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id sNt1ADURzGK/BQAAMHmgww (envelope-from ); Mon, 11 Jul 2022 12:01:57 +0000 Date: Mon, 11 Jul 2022 14:01:55 +0200 From: Oscar Salvador To: Huang Ying Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Baolin Wang , Zi Yan , Yang Shi Subject: Re: [PATCH -V2 3/7] migrate_pages(): fix THP failure counting for -ENOMEM Message-ID: References: <20220711084948.274787-1-ying.huang@intel.com> <20220711084948.274787-4-ying.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220711084948.274787-4-ying.huang@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 11, 2022 at 04:49:44PM +0800, Huang Ying wrote: > In unmap_and_move(), if the new THP cannot be allocated, -ENOMEM will > be returned, and migrate_pages() will try to split the THP unless > "reason" is MR_NUMA_MISPLACED (that is, nosplit == true). But when > nosplit == true, the THP migration failure will not be counted. This > is incorrect. So in this patch, the THP migration failure will be > counted for -ENOMEM regardless of nosplit is true or false. The > nr_failed counting isn't fixed because it's not used. Added some > comments for it per Baolin's suggestion. > > Signed-off-by: "Huang, Ying" > Fixes: 5984fabb6e82 ("mm: move_pages: report the number of non-attempted pages") > Reviewed-by: Baolin Wang > Cc: Zi Yan > Cc: Yang Shi Reviewed-by: Oscar Salvador > --- > mm/migrate.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 794312072eb3..38e2c789a9c3 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1426,11 +1426,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > /* > * When memory is low, don't bother to try to migrate > * other pages, just exit. > - * THP NUMA faulting doesn't split THP to retry. > */ > - if (is_thp && !nosplit) { > + if (is_thp) { > nr_thp_failed++; > - if (!try_split_thp(page, &thp_split_pages)) { > + /* THP NUMA faulting doesn't split THP to retry. */ > + if (!nosplit && !try_split_thp(page, &thp_split_pages)) { > nr_thp_split++; > goto retry; > } > @@ -1446,6 +1446,7 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page, > * the caller otherwise the page refcnt will be leaked. > */ > list_splice_init(&thp_split_pages, from); > + /* nr_failed isn't updated for not used */ > nr_thp_failed += thp_retry; > goto out; > case -EAGAIN: > -- > 2.30.2 > > -- Oscar Salvador SUSE Labs