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 98AB7C433EF for ; Thu, 17 Feb 2022 09:41:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238798AbiBQJmI (ORCPT ); Thu, 17 Feb 2022 04:42:08 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:47562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238800AbiBQJmG (ORCPT ); Thu, 17 Feb 2022 04:42:06 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F18B17073 for ; Thu, 17 Feb 2022 01:41:52 -0800 (PST) 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-out1.suse.de (Postfix) with ESMTPS id C133D21108; Thu, 17 Feb 2022 09:41:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1645090910; 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=wImjFANCLFR6cPTD07RUf9ZegKguk0qYibC7WDzmyME=; b=DDxqgEcnT6dFCJYPAAa4FQcongrOqUGxEbkkzjUHpNGsG4fIhzS+SXZE1E1dE0kw8iV+7o yMKcfYmcZXJGFsDw9VIOfu0uLU+NY3rgaUqNbRmjjlTrNnEGRxAXpDspDVl5eTJw5pXCWS 7u/HnQs2GHQ+wbeLVesAC6sonjafLEo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1645090910; 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=wImjFANCLFR6cPTD07RUf9ZegKguk0qYibC7WDzmyME=; b=XVskj/qAwLyEZce8KQOqtKiqBIfA/fDbx/lB508fJa59qjig4Lm6t25l04tNgvpcMo4KIk sVaBLRX5Z6NGPKBw== 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 8F4A013BBF; Thu, 17 Feb 2022 09:41:50 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id nXczIl4YDmI4KQAAMHmgww (envelope-from ); Thu, 17 Feb 2022 09:41:50 +0000 Message-ID: <83d6e082-9289-e8cb-2e40-77650e2bb375@suse.cz> Date: Thu, 17 Feb 2022 10:41:50 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH 2/6] mm/page_alloc: Track range of active PCP lists during bulk free Content-Language: en-US To: Mel Gorman , Andrew Morton Cc: Aaron Lu , Dave Hansen , Michal Hocko , Jesper Dangaard Brouer , LKML , Linux-MM References: <20220217002227.5739-1-mgorman@techsingularity.net> <20220217002227.5739-3-mgorman@techsingularity.net> From: Vlastimil Babka In-Reply-To: <20220217002227.5739-3-mgorman@techsingularity.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/17/22 01:22, Mel Gorman wrote: > free_pcppages_bulk() frees pages in a round-robin fashion. Originally, > this was dealing only with migratetypes but storing high-order pages > means that there can be many more empty lists that are uselessly > checked. Track the minimum and maximum active pindex to reduce the > search space. > > Signed-off-by: Mel Gorman Reviewed-by: Vlastimil Babka > --- > mm/page_alloc.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 08de32cfd9bb..85cc1fe8bcc5 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1450,6 +1450,8 @@ static void free_pcppages_bulk(struct zone *zone, int count, > struct per_cpu_pages *pcp) > { > int pindex = 0; > + int min_pindex = 0; > + int max_pindex = NR_PCP_LISTS - 1; > int batch_free = 0; > int nr_freed = 0; > unsigned int order; > @@ -1475,13 +1477,20 @@ static void free_pcppages_bulk(struct zone *zone, int count, > */ > do { > batch_free++; > - if (++pindex == NR_PCP_LISTS) > - pindex = 0; > + if (++pindex > max_pindex) > + pindex = min_pindex; > list = &pcp->lists[pindex]; > - } while (list_empty(list)); > + if (!list_empty(list)) > + break; > + > + if (pindex == max_pindex) > + max_pindex--; > + if (pindex == min_pindex) > + min_pindex++; > + } while (1); > > /* This is the only non-empty list. Free them all. */ > - if (batch_free == NR_PCP_LISTS) > + if (batch_free >= max_pindex - min_pindex) > batch_free = count; > > order = pindex_to_order(pindex);