From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [merged] =?US-ASCII?Q?mm-page=5Fallocc-only-tune-sysctl=5Flowmem=5Freserve=5Frat?= =?US-ASCII?Q?io-value-once-when-changing-it.patch?= removed from -mm tree Date: Thu, 04 Jun 2020 10:18:00 -0700 Message-ID: <20200604171800.1rCSmtv-o%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Return-path: Received: from mail.kernel.org ([198.145.29.99]:39552 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729999AbgFDRSB (ORCPT ); Thu, 4 Jun 2020 13:18:01 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: bhe@redhat.com, iamjoonsoo.kim@lge.com, mgorman@techsingularity.net, mhocko@kernel.org, mm-commits@vger.kernel.org, rientjes@google.com The patch titled Subject: mm/page_alloc.c: only tune sysctl_lowmem_reserve_ratio value once when changing it has been removed from the -mm tree. Its filename was mm-page_allocc-only-tune-sysctl_lowmem_reserve_ratio-value-once-when-changing-it.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Baoquan He Subject: mm/page_alloc.c: only tune sysctl_lowmem_reserve_ratio value once when changing it Patch series "improvements about lowmem_reserve and /proc/zoneinfo", v2. This patch (of 3): When people write to /proc/sys/vm/lowmem_reserve_ratio to change sysctl_lowmem_reserve_ratio[], setup_per_zone_lowmem_reserve() is called to recalculate all ->lowmem_reserve[] for each zone of all nodes as below: static void setup_per_zone_lowmem_reserve(void) { ... for_each_online_pgdat(pgdat) { for (j = 0; j < MAX_NR_ZONES; j++) { ... while (idx) { ... if (sysctl_lowmem_reserve_ratio[idx] < 1) { sysctl_lowmem_reserve_ratio[idx] = 0; lower_zone->lowmem_reserve[j] = 0; } else { ... } } } } Meanwhile, here, sysctl_lowmem_reserve_ratio[idx] will be tuned if its value is smaller than '1'. As we know, sysctl_lowmem_reserve_ratio[] is set for zone without regarding to which node it belongs to. That means the tuning will be done on all nodes, even though it has been done in the first node. And the tuning will be done too even when init_per_zone_wmark_min() calls setup_per_zone_lowmem_reserve(), where actually nobody tries to change sysctl_lowmem_reserve_ratio[]. So now move the tuning into lowmem_reserve_ratio_sysctl_handler(), to make code logic more reasonable. Link: http://lkml.kernel.org/r/20200402140113.3696-1-bhe@redhat.com Link: http://lkml.kernel.org/r/20200402140113.3696-2-bhe@redhat.com Signed-off-by: Baoquan He Cc: Joonsoo Kim Cc: Michal Hocko Cc: Baoquan He Cc: Mel Gorman Cc: David Rientjes Signed-off-by: Andrew Morton --- mm/page_alloc.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/mm/page_alloc.c~mm-page_allocc-only-tune-sysctl_lowmem_reserve_ratio-value-once-when-changing-it +++ a/mm/page_alloc.c @@ -7704,8 +7704,7 @@ static void setup_per_zone_lowmem_reserv idx--; lower_zone = pgdat->node_zones + idx; - if (sysctl_lowmem_reserve_ratio[idx] < 1) { - sysctl_lowmem_reserve_ratio[idx] = 0; + if (!sysctl_lowmem_reserve_ratio[idx]) { lower_zone->lowmem_reserve[j] = 0; } else { lower_zone->lowmem_reserve[j] = @@ -7970,7 +7969,15 @@ int sysctl_min_slab_ratio_sysctl_handler int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos) { + int i; + proc_dointvec_minmax(table, write, buffer, length, ppos); + + for (i = 0; i < MAX_NR_ZONES; i++) { + if (sysctl_lowmem_reserve_ratio[i] < 1) + sysctl_lowmem_reserve_ratio[i] = 0; + } + setup_per_zone_lowmem_reserve(); return 0; } _ Patches currently in -mm which might be from bhe@redhat.com are