From: Yu Zhao <yuzhao@google.com>
To: Hillf Danton <hdanton@sina.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Johannes Weiner <hannes@cmpxchg.org>,
Mel Gorman <mgorman@suse.de>,
page-reclaim@google.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org
Subject: Re: [PATCH v1 00/14] Multigenerational LRU
Date: Mon, 15 Mar 2021 00:49:51 -0600 [thread overview]
Message-ID: <YE8Dj4uSPDE6HYM1@google.com> (raw)
In-Reply-To: <20210315011350.3648-1-hdanton@sina.com>
On Mon, Mar 15, 2021 at 09:13:50AM +0800, Hillf Danton wrote:
> On Sat, 13 Mar 2021 00:57:33 -0700 Yu Zhao wrote:
> > TLDR
> > ====
> > The current page reclaim is too expensive in terms of CPU usage and
> > often making poor choices about what to evict. We would like to offer
> > a performant, versatile and straightforward augment.
>
> It makes my day, Monday of thick smog in one of the far east big
> cities, to read the fresh work, something like 0b0695f2b34a that removed
> heuristics as much as possible, of a coming Mr. Kswapd.
Hi Hillf!
Sorry to hear about the smog, we don't have smog, only a few feet of
snow...
I shared the latest version of the cover letter here, if you are a fan
of Google Docs:
https://docs.google.com/document/d/1UxcpPAFNk1KpTJDKDXWekj_n6ebpQ-cwbXZlYoebTVM
And speaking of heuristics, yeah, I totally understand. We've had more
than fair share of problems with get_scan_count() and
inactive_is_low(). And we are still carrying a workaround (admittedly
a terrible one) we posted more that a decade ago, on some of our old
kernel versions:
https://lore.kernel.org/linux-mm/20101028191523.GA14972@google.com/
And people who run the Chrome browser but don't have this patch (non-
Chrome OS) had problems!
https://lore.kernel.org/linux-mm/54C77086.7090505@suse.cz/
With generation numbers, the equivalent to inactive_is_low() is
max_seq - min(min_seq[!swappiness], min_seq[1]) + 1 > MIN_NR_GENS
in get_nr_to_scan(); and the equivalent to get_scan_count() is
*file = !swappiness || min_seq[0] > min_seq[1] ||
(min_seq[0] == min_seq[1] &&
max(lruvec->evictable.isolated[0], 1UL) * (200 - swappiness) >
max(lruvec->evictable.isolated[1], 1UL) * (swappiness - 1));
in isolate_lru_gen_pages(), both in the 10th patch.
They work amazingly well for us, and hopefully for you too :)
next prev parent reply other threads:[~2021-03-15 6:50 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-13 7:57 [PATCH v1 00/14] Multigenerational LRU Yu Zhao
2021-03-13 7:57 ` [PATCH v1 01/14] include/linux/memcontrol.h: do not warn in page_memcg_rcu() if !CONFIG_MEMCG Yu Zhao
2021-03-13 15:09 ` Matthew Wilcox
2021-03-14 7:45 ` Yu Zhao
2021-03-13 7:57 ` [PATCH v1 02/14] include/linux/nodemask.h: define next_memory_node() if !CONFIG_NUMA Yu Zhao
2021-03-13 7:57 ` [PATCH v1 03/14] include/linux/huge_mm.h: define is_huge_zero_pmd() if !CONFIG_TRANSPARENT_HUGEPAGE Yu Zhao
2021-03-13 7:57 ` [PATCH v1 04/14] include/linux/cgroup.h: export cgroup_mutex Yu Zhao
2021-03-13 7:57 ` [PATCH v1 05/14] mm/swap.c: export activate_page() Yu Zhao
2021-03-13 7:57 ` [PATCH v1 06/14] mm, x86: support the access bit on non-leaf PMD entries Yu Zhao
2021-03-14 22:12 ` Zi Yan
2021-03-14 22:51 ` Matthew Wilcox
2021-03-15 0:03 ` Yu Zhao
2021-03-15 0:27 ` Zi Yan
2021-03-15 1:04 ` Yu Zhao
2021-03-14 23:22 ` Dave Hansen
2021-03-15 3:16 ` Yu Zhao
2021-03-13 7:57 ` [PATCH v1 07/14] mm/pagewalk.c: add pud_entry_post() for post-order traversals Yu Zhao
2021-03-13 7:57 ` [PATCH v1 08/14] mm/vmscan.c: refactor shrink_node() Yu Zhao
2021-03-13 7:57 ` [PATCH v1 09/14] mm: multigenerational lru: mm_struct list Yu Zhao
2021-03-15 19:40 ` Rik van Riel
2021-03-16 2:07 ` Huang, Ying
2021-03-16 3:57 ` Yu Zhao
2021-03-16 6:44 ` Huang, Ying
2021-03-16 7:56 ` Yu Zhao
2021-03-17 3:37 ` Huang, Ying
2021-03-17 10:46 ` Yu Zhao
2021-03-22 3:13 ` Huang, Ying
2021-03-22 8:08 ` Yu Zhao
2021-03-24 6:58 ` Huang, Ying
2021-04-10 18:48 ` Yu Zhao
2021-04-13 3:06 ` Huang, Ying
2021-03-13 7:57 ` [PATCH v1 10/14] mm: multigenerational lru: core Yu Zhao
2021-03-15 2:02 ` Andi Kleen
2021-03-15 3:37 ` Yu Zhao
2021-03-13 7:57 ` [PATCH v1 11/14] mm: multigenerational lru: page activation Yu Zhao
2021-03-16 16:34 ` Matthew Wilcox
2021-03-16 21:29 ` Yu Zhao
2021-03-13 7:57 ` [PATCH v1 12/14] mm: multigenerational lru: user space interface Yu Zhao
2021-03-13 7:57 ` [PATCH v1 13/14] mm: multigenerational lru: Kconfig Yu Zhao
2021-03-13 7:57 ` [PATCH v1 14/14] mm: multigenerational lru: documentation Yu Zhao
2021-03-19 9:31 ` Alex Shi
2021-03-22 6:09 ` Yu Zhao
2021-03-14 22:48 ` [PATCH v1 00/14] Multigenerational LRU Zi Yan
2021-03-15 0:52 ` Yu Zhao
[not found] ` <20210315011350.3648-1-hdanton@sina.com>
2021-03-15 6:49 ` Yu Zhao [this message]
2021-03-15 18:00 ` Dave Hansen
2021-03-16 2:24 ` Yu Zhao
2021-03-16 14:50 ` Dave Hansen
2021-03-16 20:30 ` Yu Zhao
2021-03-16 21:14 ` Dave Hansen
2021-04-10 9:21 ` Yu Zhao
2021-04-13 3:02 ` Huang, Ying
2021-04-13 23:00 ` Yu Zhao
2021-03-15 18:38 ` Yang Shi
2021-03-16 3:38 ` Yu Zhao
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