From: Rik van Riel <riel@surriel.com> To: "Huang, Ying" <ying.huang@intel.com>, Yu Zhao <yuzhao@google.com> Cc: Dave Chinner <david@fromorbit.com>, Jens Axboe <axboe@kernel.dk>, SeongJae Park <sj38.park@gmail.com>, Linux-MM <linux-mm@kvack.org>, Andi Kleen <ak@linux.intel.com>, Andrew Morton <akpm@linux-foundation.org>, Benjamin Manes <ben.manes@gmail.com>, Dave Hansen <dave.hansen@linux.intel.com>, Hillf Danton <hdanton@sina.com>, Johannes Weiner <hannes@cmpxchg.org>, Jonathan Corbet <corbet@lwn.net>, Joonsoo Kim <iamjoonsoo.kim@lge.com>, Matthew Wilcox <willy@infradead.org>, Mel Gorman <mgorman@suse.de>, Miaohe Lin <linmiaohe@huawei.com>, Michael Larabel <michael@michaellarabel.com>, Michal Hocko <mhocko@suse.com>, Michel Lespinasse <michel@lespinasse.org>, Roman Gushchin <guro@fb.com>, Rong Chen <rong.a.chen@intel.com>, SeongJae Park <sjpark@amazon.de>, Tim Chen <tim.c.chen@linux.intel.com>, Vlastimil Babka <vbabka@suse.cz>, Yang Shi <shy828301@gmail.com>, Zi Yan <ziy@nvidia.com>, linux-kernel <linux-kernel@vger.kernel.org>, lkp@lists.01.org, Kernel Page Reclaim v2 <page-reclaim@google.com> Subject: Re: [PATCH v2 00/16] Multigenerational LRU Framework Date: Wed, 14 Apr 2021 09:51:51 -0400 [thread overview] Message-ID: <93308ea276cfe7997c29ce7132516e830e8fec40.camel@surriel.com> (raw) In-Reply-To: <87lf9lqnit.fsf@yhuang6-desk1.ccr.corp.intel.com> [-- Attachment #1: Type: text/plain, Size: 1888 bytes --] On Wed, 2021-04-14 at 16:27 +0800, Huang, Ying wrote: > Yu Zhao <yuzhao@google.com> writes: > > > On Wed, Apr 14, 2021 at 12:15 AM Huang, Ying <ying.huang@intel.com> > > wrote: > > > > > NUMA Optimization > > ----------------- > > Support NUMA policies and per-node RSS counters. > > > > We only can move forward one step at a time. Fair? > > You don't need to implement that now definitely. But we can discuss > the > possible solution now. That was my intention, too. I want to make sure we don't end up "painting ourselves into a corner" by moving in some direction we have no way to get out of. The patch set looks promising, but we need some plan to avoid the worst case behaviors that forced us into rmap based scanning initially. > Note that it's possible that only some processes are bound to some > NUMA > nodes, while other processes aren't bound. For workloads like PostgresQL or Oracle, it is common to have maybe 70% of memory in a large shared memory segment, spread between all the NUMA nodes, and mapped into hundreds, if not thousands, of processes in the system. Now imagine we have an 8 node system, and memory pressure in the DMA32 zone of node 0. How will the current VM behave? Wha t will the virtual scanning need to do? If we can come up with a solution to make virtual scanning scale for that kind of workload, great. If not ... if it turns out most of the benefits of the multigeneratinal LRU framework come from sorting the pages into multiple LRUs, and from being able to easily reclaim unmapped pages before having to scan mapped ones, could it be an idea to implement that first, independently from virtual scanning? I am all for improving our page reclaim system, I just want to make sure we don't revisit the old traps that forced us where we are today :) -- All Rights Reversed. [-- Attachment #2: This is a digitally signed message part --] [-- Type: application/pgp-signature, Size: 488 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: Rik van Riel <riel@surriel.com> To: lkp@lists.01.org Subject: Re: [PATCH v2 00/16] Multigenerational LRU Framework Date: Wed, 14 Apr 2021 09:51:51 -0400 [thread overview] Message-ID: <93308ea276cfe7997c29ce7132516e830e8fec40.camel@surriel.com> (raw) In-Reply-To: <87lf9lqnit.fsf@yhuang6-desk1.ccr.corp.intel.com> [-- Attachment #1: Type: text/plain, Size: 1888 bytes --] On Wed, 2021-04-14 at 16:27 +0800, Huang, Ying wrote: > Yu Zhao <yuzhao@google.com> writes: > > > On Wed, Apr 14, 2021 at 12:15 AM Huang, Ying <ying.huang@intel.com> > > wrote: > > > > > NUMA Optimization > > ----------------- > > Support NUMA policies and per-node RSS counters. > > > > We only can move forward one step at a time. Fair? > > You don't need to implement that now definitely. But we can discuss > the > possible solution now. That was my intention, too. I want to make sure we don't end up "painting ourselves into a corner" by moving in some direction we have no way to get out of. The patch set looks promising, but we need some plan to avoid the worst case behaviors that forced us into rmap based scanning initially. > Note that it's possible that only some processes are bound to some > NUMA > nodes, while other processes aren't bound. For workloads like PostgresQL or Oracle, it is common to have maybe 70% of memory in a large shared memory segment, spread between all the NUMA nodes, and mapped into hundreds, if not thousands, of processes in the system. Now imagine we have an 8 node system, and memory pressure in the DMA32 zone of node 0. How will the current VM behave? Wha t will the virtual scanning need to do? If we can come up with a solution to make virtual scanning scale for that kind of workload, great. If not ... if it turns out most of the benefits of the multigeneratinal LRU framework come from sorting the pages into multiple LRUs, and from being able to easily reclaim unmapped pages before having to scan mapped ones, could it be an idea to implement that first, independently from virtual scanning? I am all for improving our page reclaim system, I just want to make sure we don't revisit the old traps that forced us where we are today :) -- All Rights Reversed. [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2021-04-14 13:52 UTC|newest] Thread overview: 163+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-04-13 6:56 [PATCH v2 00/16] Multigenerational LRU Framework Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 01/16] include/linux/memcontrol.h: do not warn in page_memcg_rcu() if !CONFIG_MEMCG Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 02/16] include/linux/nodemask.h: define next_memory_node() if !CONFIG_NUMA Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 03/16] include/linux/huge_mm.h: define is_huge_zero_pmd() if !CONFIG_TRANSPARENT_HUGEPAGE Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 04/16] include/linux/cgroup.h: export cgroup_mutex Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 05/16] mm/swap.c: export activate_page() Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 06/16] mm, x86: support the access bit on non-leaf PMD entries Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 07/16] mm/vmscan.c: refactor shrink_node() Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 08/16] mm: multigenerational lru: groundwork Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 09/16] mm: multigenerational lru: activation Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 10/16] mm: multigenerational lru: mm_struct list Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-14 14:36 ` Matthew Wilcox 2021-04-14 14:36 ` Matthew Wilcox 2021-04-13 6:56 ` [PATCH v2 11/16] mm: multigenerational lru: aging Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 12/16] mm: multigenerational lru: eviction Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 13/16] mm: multigenerational lru: page reclaim Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` [PATCH v2 14/16] mm: multigenerational lru: user interface Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 22:39 ` kernel test robot 2021-04-13 22:39 ` kernel test robot 2021-04-13 6:56 ` [PATCH v2 15/16] mm: multigenerational lru: Kconfig Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 16:19 ` kernel test robot 2021-04-13 16:19 ` kernel test robot 2021-04-14 4:54 ` kernel test robot 2021-04-14 4:54 ` kernel test robot 2021-04-13 6:56 ` [PATCH v2 16/16] mm: multigenerational lru: documentation Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 6:56 ` Yu Zhao 2021-04-13 7:51 ` [PATCH v2 00/16] Multigenerational LRU Framework SeongJae Park 2021-04-13 7:51 ` SeongJae Park 2021-04-13 16:13 ` Jens Axboe 2021-04-13 16:13 ` Jens Axboe 2021-04-13 16:42 ` SeongJae Park 2021-04-13 16:42 ` SeongJae Park 2021-04-13 23:14 ` Dave Chinner 2021-04-13 23:14 ` Dave Chinner 2021-04-14 2:29 ` Rik van Riel 2021-04-14 2:29 ` Rik van Riel 2021-04-14 2:29 ` Rik van Riel 2021-04-14 4:13 ` Yu Zhao 2021-04-14 4:13 ` Yu Zhao 2021-04-14 6:15 ` Huang, Ying 2021-04-14 6:15 ` Huang, Ying 2021-04-14 6:15 ` Huang, Ying 2021-04-14 7:58 ` Yu Zhao 2021-04-14 7:58 ` Yu Zhao 2021-04-14 7:58 ` Yu Zhao 2021-04-14 8:27 ` Huang, Ying 2021-04-14 8:27 ` Huang, Ying 2021-04-14 8:27 ` Huang, Ying 2021-04-14 13:51 ` Rik van Riel [this message] 2021-04-14 13:51 ` Rik van Riel 2021-04-14 13:51 ` Rik van Riel 2021-04-14 15:56 ` Andi Kleen 2021-04-14 15:56 ` Andi Kleen 2021-04-14 15:58 ` [page-reclaim] " Shakeel Butt 2021-04-14 15:58 ` Shakeel Butt 2021-04-14 15:58 ` Shakeel Butt 2021-04-14 18:45 ` Yu Zhao 2021-04-14 18:45 ` Yu Zhao 2021-04-14 18:45 ` Yu Zhao 2021-04-14 15:51 ` Andi Kleen 2021-04-14 15:51 ` Andi Kleen 2021-04-14 15:58 ` Rik van Riel 2021-04-14 15:58 ` Rik van Riel 2021-04-14 15:58 ` Rik van Riel 2021-04-14 19:14 ` Yu Zhao 2021-04-14 19:14 ` Yu Zhao 2021-04-14 19:14 ` Yu Zhao 2021-04-14 19:41 ` Rik van Riel 2021-04-14 19:41 ` Rik van Riel 2021-04-14 19:41 ` Rik van Riel 2021-04-14 20:08 ` Yu Zhao 2021-04-14 20:08 ` Yu Zhao 2021-04-14 20:08 ` Yu Zhao 2021-04-14 19:04 ` Yu Zhao 2021-04-14 19:04 ` Yu Zhao 2021-04-14 19:04 ` Yu Zhao 2021-04-15 3:00 ` Andi Kleen 2021-04-15 3:00 ` Andi Kleen 2021-04-15 7:13 ` Yu Zhao 2021-04-15 7:13 ` Yu Zhao 2021-04-15 7:13 ` Yu Zhao 2021-04-15 8:19 ` Huang, Ying 2021-04-15 8:19 ` Huang, Ying 2021-04-15 8:19 ` Huang, Ying 2021-04-15 9:57 ` Michel Lespinasse 2021-04-18 6:48 ` Michel Lespinasse 2021-04-24 2:33 ` Yu Zhao 2021-04-24 2:33 ` Yu Zhao 2021-04-24 2:33 ` Yu Zhao 2021-04-24 3:30 ` Andi Kleen 2021-04-24 3:30 ` Andi Kleen 2021-04-24 4:16 ` Yu Zhao 2021-04-24 4:16 ` Yu Zhao 2021-04-24 4:16 ` Yu Zhao 2021-04-14 3:40 ` Yu Zhao 2021-04-14 3:40 ` Yu Zhao 2021-04-14 3:40 ` Yu Zhao 2021-04-14 4:50 ` Dave Chinner 2021-04-14 4:50 ` Dave Chinner 2021-04-14 7:16 ` Yu Zhao 2021-04-14 7:16 ` Yu Zhao 2021-04-14 7:16 ` Yu Zhao 2021-04-14 10:00 ` Yu Zhao 2021-04-14 10:00 ` Yu Zhao 2021-04-15 1:36 ` Dave Chinner 2021-04-15 1:36 ` Dave Chinner 2021-04-24 21:21 ` Yu Zhao 2021-04-24 21:21 ` Yu Zhao 2021-04-24 21:21 ` Yu Zhao 2021-04-14 14:43 ` Jens Axboe 2021-04-14 14:43 ` Jens Axboe 2021-04-14 19:42 ` Yu Zhao 2021-04-14 19:42 ` Yu Zhao 2021-04-14 19:42 ` Yu Zhao 2021-04-15 1:21 ` Dave Chinner 2021-04-15 1:21 ` Dave Chinner 2021-04-14 17:43 ` Johannes Weiner 2021-04-14 17:43 ` Johannes Weiner 2021-04-27 10:35 ` Yu Zhao 2021-04-27 10:35 ` Yu Zhao 2021-04-27 10:35 ` Yu Zhao 2021-04-29 23:46 ` Konstantin Kharlamov 2021-04-29 23:46 ` Konstantin Kharlamov 2021-04-29 23:46 ` Konstantin Kharlamov 2021-04-30 6:37 ` Konstantin Kharlamov 2021-04-30 6:37 ` Konstantin Kharlamov 2021-04-30 6:37 ` Konstantin Kharlamov 2021-04-30 19:31 ` Yu Zhao 2021-04-30 19:31 ` Yu Zhao 2021-04-30 19:31 ` Yu Zhao
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