From: Yu Zhao <yuzhao@google.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Mel Gorman <mgorman@suse.de>, Michal Hocko <mhocko@kernel.org>
Cc: "Andi Kleen" <ak@linux.intel.com>,
"Aneesh Kumar" <aneesh.kumar@linux.ibm.com>,
"Barry Song" <21cnbao@gmail.com>,
"Catalin Marinas" <catalin.marinas@arm.com>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Hillf Danton" <hdanton@sina.com>, "Jens Axboe" <axboe@kernel.dk>,
"Jesse Barnes" <jsbarnes@google.com>,
"Jonathan Corbet" <corbet@lwn.net>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Matthew Wilcox" <willy@infradead.org>,
"Michael Larabel" <Michael@michaellarabel.com>,
"Mike Rapoport" <rppt@kernel.org>,
"Rik van Riel" <riel@surriel.com>,
"Vlastimil Babka" <vbabka@suse.cz>,
"Will Deacon" <will@kernel.org>,
"Ying Huang" <ying.huang@intel.com>,
linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
page-reclaim@google.com, x86@kernel.org,
"Brian Geffon" <bgeffon@google.com>,
"Jan Alexander Steffens" <heftig@archlinux.org>,
"Oleksandr Natalenko" <oleksandr@natalenko.name>,
"Steven Barrett" <steven@liquorix.net>,
"Suleiman Souhlal" <suleiman@google.com>,
"Daniel Byrne" <djbyrne@mtu.edu>,
"Donald Carr" <d@chaos-reins.com>,
"Holger Hoffstätte" <holger@applied-asynchrony.com>,
"Konstantin Kharlamov" <Hi-Angel@yandex.ru>,
"Shuang Zhai" <szhai2@cs.rochester.edu>,
"Sofia Trinh" <sofia.trinh@edi.works>
Subject: Re: [PATCH v7 07/12] mm: multigenerational LRU: support page table walks
Date: Tue, 8 Feb 2022 01:39:27 -0700 [thread overview]
Message-ID: <YgIsPyTImfaWI10k@google.com> (raw)
In-Reply-To: <20220208081902.3550911-8-yuzhao@google.com>
On Tue, Feb 08, 2022 at 01:18:57AM -0700, Yu Zhao wrote:
> To avoid confusions, the term "iteration" specifically means the
> traversal of an entire mm_struct list; the term "walk" will be applied
> to page tables and the rmap, as usual.
>
> To further exploit spatial locality, the aging prefers to walk page
> tables to search for young PTEs and promote hot pages. A runtime
> switch will be added in the next patch to enable or disable this
> feature. Without it, the aging relies on the rmap only.
Clarified that page table scanning is optional as requested here:
https://lore.kernel.org/linux-mm/YdxEqFPLDf+wI0xX@dhcp22.suse.cz/
> NB: this feature has nothing similar with the page table scanning in
> the 2.4 kernel [1], which searches page tables for old PTEs, adds cold
> pages to swapcache and unmap them.
>
> An mm_struct list is maintained for each memcg, and an mm_struct
> follows its owner task to the new memcg when this task is migrated.
> Given an lruvec, the aging iterates lruvec_memcg()->mm_list and calls
> walk_page_range() with each mm_struct on this list to promote hot
> pages before it increments max_seq.
>
> When multiple page table walkers (threads) iterate the same list, each
> of them gets a unique mm_struct; therefore they can run concurrently.
> Page table walkers ignore any misplaced pages, e.g., if an mm_struct
> was migrated, pages it left in the previous memcg won't be promoted
> when its current memcg is under reclaim. Similarly, page table walkers
> won't promote pages from nodes other than the one under reclaim.
Clarified the interaction between task migration and reclaim as requested here:
https://lore.kernel.org/linux-mm/YdxPEdsfl771Z7IX@dhcp22.suse.cz/
<snipped>
> Server benchmark results:
> Single workload:
> fio (buffered I/O): no change
>
> Single workload:
> memcached (anon): +[5.5, 7.5]%
> Ops/sec KB/sec
> patch1-6: 1015292.83 39490.38
> patch1-7: 1080856.82 42040.53
>
> Configurations:
> no change
>
> Client benchmark results:
> kswapd profiles:
> patch1-6
> 45.49% lzo1x_1_do_compress (real work)
> 7.38% page_vma_mapped_walk
> 7.24% _raw_spin_unlock_irq
> 2.64% ptep_clear_flush
> 2.31% __zram_bvec_write
> 2.13% do_raw_spin_lock
> 2.09% lru_gen_look_around
> 1.89% free_unref_page_list
> 1.85% memmove
> 1.74% obj_malloc
>
> patch1-7
> 47.73% lzo1x_1_do_compress (real work)
> 6.84% page_vma_mapped_walk
> 6.14% _raw_spin_unlock_irq
> 2.86% walk_pte_range
> 2.79% ptep_clear_flush
> 2.24% __zram_bvec_write
> 2.10% do_raw_spin_lock
> 1.94% free_unref_page_list
> 1.80% memmove
> 1.75% obj_malloc
>
> Configurations:
> no change
Added benchmark results to show the difference between page table
scanning and no page table scanning, as requested here:
https://lore.kernel.org/linux-mm/Ye6xS6xUD1SORdHJ@dhcp22.suse.cz/
<snipped>
> +static void walk_mm(struct lruvec *lruvec, struct mm_struct *mm, struct lru_gen_mm_walk *walk)
> +{
> + static const struct mm_walk_ops mm_walk_ops = {
> + .test_walk = should_skip_vma,
> + .p4d_entry = walk_pud_range,
> + };
> +
> + int err;
> + struct mem_cgroup *memcg = lruvec_memcg(lruvec);
> +
> + walk->next_addr = FIRST_USER_ADDRESS;
> +
> + do {
> + err = -EBUSY;
> +
> + /* folio_update_gen() requires stable folio_memcg() */
> + if (!mem_cgroup_trylock_pages(memcg))
> + break;
Added a comment on the stable folio_memcg() requirement as requested
here:
https://lore.kernel.org/linux-mm/Yd6q0QdLVTS53vu4@dhcp22.suse.cz/
<snipped>
> +static struct lru_gen_mm_walk *alloc_mm_walk(void)
> +{
> + if (current->reclaim_state && current->reclaim_state->mm_walk)
> + return current->reclaim_state->mm_walk;
> +
> + return kzalloc(sizeof(struct lru_gen_mm_walk),
> + __GFP_HIGH | __GFP_NOMEMALLOC | __GFP_NOWARN);
> +}
Replaced kvzalloc() with kzalloc() as requested here:
https://lore.kernel.org/linux-mm/Yd6tafG3CS7BoRYn@dhcp22.suse.cz/
Replaced GFP_KERNEL with __GFP_HIGH|__GFP_NOMEMALLOC|__GFP_NOWARN as
requested here:
https://lore.kernel.org/linux-mm/YefddYm8FAfJalNa@dhcp22.suse.cz/
<snipped>
next prev parent reply other threads:[~2022-02-08 8:39 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-08 8:18 [PATCH v7 00/12] Multigenerational LRU Framework Yu Zhao
2022-02-08 8:18 ` [PATCH v7 01/12] mm: x86, arm64: add arch_has_hw_pte_young() Yu Zhao
2022-02-08 8:24 ` Yu Zhao
2022-02-08 10:33 ` Will Deacon
2022-02-08 8:18 ` [PATCH v7 02/12] mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG Yu Zhao
2022-02-08 8:27 ` Yu Zhao
2022-02-08 8:18 ` [PATCH v7 03/12] mm/vmscan.c: refactor shrink_node() Yu Zhao
2022-02-08 8:18 ` [PATCH v7 04/12] mm: multigenerational LRU: groundwork Yu Zhao
2022-02-08 8:28 ` Yu Zhao
2022-02-10 20:41 ` Johannes Weiner
2022-02-15 9:43 ` Yu Zhao
2022-02-15 21:53 ` Johannes Weiner
2022-02-21 8:14 ` Yu Zhao
2022-02-23 21:18 ` Yu Zhao
2022-02-25 16:34 ` Minchan Kim
2022-03-03 15:29 ` Johannes Weiner
2022-03-03 19:26 ` Yu Zhao
2022-03-03 21:43 ` Johannes Weiner
2022-03-11 10:16 ` Barry Song
2022-03-11 23:45 ` Yu Zhao
2022-03-12 10:37 ` Barry Song
2022-03-12 21:11 ` Yu Zhao
2022-03-13 4:57 ` Barry Song
2022-03-14 11:11 ` Barry Song
2022-03-14 16:45 ` Yu Zhao
2022-03-14 23:38 ` Barry Song
[not found] ` <CAOUHufa9eY44QadfGTzsxa2=hEvqwahXd7Canck5Gt-N6c4UKA@mail.gmail.com>
[not found] ` <CAGsJ_4zvj5rmz7DkW-kJx+jmUT9G8muLJ9De--NZma9ey0Oavw@mail.gmail.com>
2022-03-15 10:29 ` Barry Song
2022-03-16 2:46 ` Yu Zhao
2022-03-16 4:37 ` Barry Song
2022-03-16 5:44 ` Yu Zhao
2022-03-16 6:06 ` Barry Song
2022-03-16 21:37 ` Yu Zhao
2022-02-10 21:37 ` Matthew Wilcox
2022-02-13 21:16 ` Yu Zhao
2022-02-08 8:18 ` [PATCH v7 05/12] mm: multigenerational LRU: minimal implementation Yu Zhao
2022-02-08 8:33 ` Yu Zhao
2022-02-08 16:50 ` Johannes Weiner
2022-02-10 2:53 ` Yu Zhao
2022-02-13 10:04 ` Hillf Danton
2022-02-17 0:13 ` Yu Zhao
2022-02-23 8:27 ` Huang, Ying
2022-02-23 9:36 ` Yu Zhao
2022-02-24 0:59 ` Huang, Ying
2022-02-24 1:34 ` Yu Zhao
2022-02-24 3:31 ` Huang, Ying
2022-02-24 4:09 ` Yu Zhao
2022-02-24 5:27 ` Huang, Ying
2022-02-24 5:35 ` Yu Zhao
2022-02-08 8:18 ` [PATCH v7 06/12] mm: multigenerational LRU: exploit locality in rmap Yu Zhao
2022-02-08 8:40 ` Yu Zhao
2022-02-08 8:18 ` [PATCH v7 07/12] mm: multigenerational LRU: support page table walks Yu Zhao
2022-02-08 8:39 ` Yu Zhao [this message]
2022-02-08 8:18 ` [PATCH v7 08/12] mm: multigenerational LRU: optimize multiple memcgs Yu Zhao
2022-02-08 8:18 ` [PATCH v7 09/12] mm: multigenerational LRU: runtime switch Yu Zhao
2022-02-08 8:42 ` Yu Zhao
2022-02-08 8:19 ` [PATCH v7 10/12] mm: multigenerational LRU: thrashing prevention Yu Zhao
2022-02-08 8:43 ` Yu Zhao
2022-02-08 8:19 ` [PATCH v7 11/12] mm: multigenerational LRU: debugfs interface Yu Zhao
2022-02-18 18:56 ` [page-reclaim] " David Rientjes
2022-02-08 8:19 ` [PATCH v7 12/12] mm: multigenerational LRU: documentation Yu Zhao
2022-02-08 8:44 ` Yu Zhao
2022-02-14 10:28 ` Mike Rapoport
2022-02-16 3:22 ` Yu Zhao
2022-02-21 9:01 ` Mike Rapoport
2022-02-22 1:47 ` Yu Zhao
2022-02-23 10:58 ` Mike Rapoport
2022-02-23 21:20 ` Yu Zhao
2022-02-08 10:11 ` [PATCH v7 00/12] Multigenerational LRU Framework Oleksandr Natalenko
2022-02-08 11:14 ` Michal Hocko
2022-02-08 11:23 ` Oleksandr Natalenko
2022-02-11 20:12 ` Alexey Avramov
2022-02-12 21:01 ` Yu Zhao
2022-03-03 6:06 ` Vaibhav Jain
2022-03-03 6:47 ` Yu Zhao
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YgIsPyTImfaWI10k@google.com \
--to=yuzhao@google.com \
--cc=21cnbao@gmail.com \
--cc=Hi-Angel@yandex.ru \
--cc=Michael@michaellarabel.com \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=aneesh.kumar@linux.ibm.com \
--cc=axboe@kernel.dk \
--cc=bgeffon@google.com \
--cc=catalin.marinas@arm.com \
--cc=corbet@lwn.net \
--cc=d@chaos-reins.com \
--cc=dave.hansen@linux.intel.com \
--cc=djbyrne@mtu.edu \
--cc=hannes@cmpxchg.org \
--cc=hdanton@sina.com \
--cc=heftig@archlinux.org \
--cc=holger@applied-asynchrony.com \
--cc=jsbarnes@google.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mgorman@suse.de \
--cc=mhocko@kernel.org \
--cc=oleksandr@natalenko.name \
--cc=page-reclaim@google.com \
--cc=riel@surriel.com \
--cc=rppt@kernel.org \
--cc=sofia.trinh@edi.works \
--cc=steven@liquorix.net \
--cc=suleiman@google.com \
--cc=szhai2@cs.rochester.edu \
--cc=torvalds@linux-foundation.org \
--cc=vbabka@suse.cz \
--cc=will@kernel.org \
--cc=willy@infradead.org \
--cc=x86@kernel.org \
--cc=ying.huang@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).