From: Mel Gorman <email@example.com> To: Dave Hansen <firstname.lastname@example.org> Cc: Linux-MM <email@example.com>, Dave Hansen <firstname.lastname@example.org>, Matthew Wilcox <email@example.com>, Vlastimil Babka <firstname.lastname@example.org>, Michal Hocko <email@example.com>, Nicholas Piggin <firstname.lastname@example.org>, LKML <email@example.com> Subject: Re: [PATCH 6/6] mm/page_alloc: Introduce vm.percpu_pagelist_high_fraction Date: Mon, 24 May 2021 10:25:30 +0100 [thread overview] Message-ID: <20210524092530.GE30378@techsingularity.net> (raw) In-Reply-To: <firstname.lastname@example.org> On Fri, May 21, 2021 at 03:57:20PM -0700, Dave Hansen wrote: > On 5/21/21 3:28 AM, Mel Gorman wrote: > > This introduces a new sysctl vm.percpu_pagelist_high_fraction. It is > > similar to the old vm.percpu_pagelist_fraction except it only adjusts > > pcp->high to potentially reduce zone->lock contention while preserving > > allocation latency when PCP lists have to be refilled. > > Look at me... Five patches later and I already forgot what the old one > did and why it stinks. I wonder if you might do a wee bit of compare > and contrast. Something like: > > The old vm.percpu_pagelist_fraction increased both the batch and > high limits for the per-cpu page allocator. Its worst feature > was that it led to absurdly large batch sizes that incurred > nasty worst-case allocation latency. > > This new sysctl in comparison... > > Anyway, the approach looks sound to me. The batch size isn't important > now, especially given the auto-scaling in patch 4. > > Acked-by: Dave Hansen <email@example.com> Thanks, I updated the changelog and hopefully it is better. -- Mel Gorman SUSE Labs
next prev parent reply other threads:[~2021-05-24 9:25 UTC|newest] Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-21 10:28 [RFC PATCH 0/6] Calculate pcp->high based on zone sizes and active CPUs Mel Gorman 2021-05-21 10:28 ` [PATCH 1/6] mm/page_alloc: Delete vm.percpu_pagelist_fraction Mel Gorman 2021-05-21 21:04 ` Dave Hansen 2021-05-21 10:28 ` [PATCH 2/6] mm/page_alloc: Disassociate the pcp->high from pcp->batch Mel Gorman 2021-05-21 21:52 ` Dave Hansen 2021-05-24 8:32 ` Mel Gorman 2021-05-21 10:28 ` [PATCH 3/6] mm/page_alloc: Adjust pcp->high after CPU hotplug events Mel Gorman 2021-05-21 22:13 ` Dave Hansen 2021-05-24 9:07 ` Mel Gorman 2021-05-24 15:52 ` Dave Hansen 2021-05-24 16:01 ` Mel Gorman 2021-05-21 10:28 ` [PATCH 4/6] mm/page_alloc: Scale the number of pages that are batch freed Mel Gorman 2021-05-21 22:36 ` Dave Hansen 2021-05-24 9:12 ` Mel Gorman 2021-05-21 10:28 ` [PATCH 5/6] mm/page_alloc: Limit the number of pages on PCP lists when reclaim is active Mel Gorman 2021-05-21 22:44 ` Dave Hansen 2021-05-24 9:22 ` Mel Gorman 2021-05-21 10:28 ` [PATCH 6/6] mm/page_alloc: Introduce vm.percpu_pagelist_high_fraction Mel Gorman 2021-05-21 22:57 ` Dave Hansen 2021-05-24 9:25 ` Mel Gorman [this message] 2021-05-25 8:01 [PATCH 0/6 v2] Calculate pcp->high based on zone sizes and active CPUs Mel Gorman 2021-05-25 8:01 ` [PATCH 6/6] mm/page_alloc: Introduce vm.percpu_pagelist_high_fraction Mel Gorman 2021-05-28 11:59 ` Vlastimil Babka 2021-05-28 12:53 ` Mel Gorman 2021-05-28 14:38 ` Vlastimil Babka
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