From: Barry Song <21cnbao@gmail.com>
To: Yu Zhao <yuzhao@google.com>
Cc: "Andrew Morton" <akpm@linux-foundation.org>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Andi Kleen" <ak@linux.intel.com>,
"Aneesh Kumar" <aneesh.kumar@linux.ibm.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>,
"Johannes Weiner" <hannes@cmpxchg.org>,
"Jonathan Corbet" <corbet@lwn.net>,
"Matthew Wilcox" <willy@infradead.org>,
"Mel Gorman" <mgorman@suse.de>,
"Michael Larabel" <Michael@michaellarabel.com>,
"Michal Hocko" <mhocko@kernel.org>,
"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>,
LAK <linux-arm-kernel@lists.infradead.org>,
"Linux Doc Mailing List" <linux-doc@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
"Kernel Page Reclaim v2" <page-reclaim@google.com>,
x86 <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>,
"Vaibhav Jain" <vaibhav@linux.ibm.com>
Subject: Re: [PATCH v9 10/14] mm: multi-gen LRU: kill switch
Date: Tue, 22 Mar 2022 21:45:23 +1300 [thread overview]
Message-ID: <CAGsJ_4wPWRkmioxGYOwZ9KwdiJUUdgH9Xd38MJH6B2sKJNG+iA@mail.gmail.com> (raw)
In-Reply-To: <CAOUHufbP7kHquWiD3VsmD=veNFF2v_E9HWqdYSMbS1nPJic0Fg@mail.gmail.com>
On Tue, Mar 22, 2022 at 9:20 PM Yu Zhao <yuzhao@google.com> wrote:
>
> On Tue, Mar 22, 2022 at 1:47 AM Barry Song <21cnbao@gmail.com> wrote:
> >
> ...
> > > +static bool drain_evictable(struct lruvec *lruvec)
> > > +{
> > > + int gen, type, zone;
> > > + int remaining = MAX_LRU_BATCH;
> > > +
> > > + for_each_gen_type_zone(gen, type, zone) {
> > > + struct list_head *head = &lruvec->lrugen.lists[gen][type][zone];
> > > +
> > > + while (!list_empty(head)) {
> > > + bool success;
> > > + struct folio *folio = lru_to_folio(head);
> > > +
> > > + VM_BUG_ON_FOLIO(folio_test_unevictable(folio), folio);
> > > + VM_BUG_ON_FOLIO(folio_test_active(folio), folio);
> > > + VM_BUG_ON_FOLIO(folio_is_file_lru(folio) != type, folio);
> > > + VM_BUG_ON_FOLIO(folio_zonenum(folio) != zone, folio);
> > > +
> > > + success = lru_gen_del_folio(lruvec, folio, false);
> > > + VM_BUG_ON(!success);
> > > + lruvec_add_folio(lruvec, folio);
> >
> > for example, max_seq=4(GEN=0) and max_seq-1=3, then we are supposed to put
> > max_seq in the head of active list. but your code seems to be putting max_seq-1
> > after putting max_seq, then max_seq is more likely to be evicted
> > afterwards as it
> > is in the tail of the active list.
>
> This is correct.
maybe something like below can fix it:
#define for_each_gen_type_zone(gen, type, zone)
\
- for ((gen) = 0; (gen) < MAX_NR_GENS; (gen)++) \
+ for (int seq = min_seq[type], (gen)=(seq_to_gen(seq)); seq <=
max_seq ; seq++) \
for ((type) = 0; (type) < ANON_AND_FILE; (type)++) \
for ((zone) = 0; (zone) < MAX_NR_ZONES; (zone)++)
but i am not quite sure it is worth it if we don't switch mglru/lru that
often. so it is all up to you, either fix it or put a comment to describe
we are not trying to make an active list with completely the same
temperature (hot/cold) as pages were in mglru lists.
>
> > anyway, it might not be so important. I can't imagine we will
> > frequently switch mglru
> > with lru dynamically. will we?
>
> I certainly hope not :)
me too.
Thanks
Barry
next prev parent reply other threads:[~2022-03-22 8:45 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-09 2:12 [PATCH v9 00/14] Multi-Gen LRU Framework Yu Zhao
2022-03-09 2:12 ` [PATCH v9 01/14] mm: x86, arm64: add arch_has_hw_pte_young() Yu Zhao
2022-03-11 10:55 ` Barry Song
2022-03-11 22:57 ` Yu Zhao
2022-03-09 2:12 ` [PATCH v9 02/14] mm: x86: add CONFIG_ARCH_HAS_NONLEAF_PMD_YOUNG Yu Zhao
2022-03-16 22:15 ` Barry Song
2022-03-09 2:12 ` [PATCH v9 03/14] mm/vmscan.c: refactor shrink_node() Yu Zhao
2022-03-18 1:15 ` Barry Song
2022-03-09 2:12 ` [PATCH v9 04/14] Revert "include/linux/mm_inline.h: fold __update_lru_size() into its sole caller" Yu Zhao
2022-03-09 2:12 ` [PATCH v9 05/14] mm: multi-gen LRU: groundwork Yu Zhao
2022-03-14 8:08 ` Huang, Ying
2022-03-14 9:30 ` Yu Zhao
2022-03-15 0:34 ` Huang, Ying
2022-03-15 0:50 ` Yu Zhao
2022-03-21 18:58 ` Justin Forbes
2022-03-21 19:17 ` Prarit Bhargava
2022-03-22 4:52 ` Yu Zhao
2022-03-16 23:25 ` Barry Song
2022-03-21 9:04 ` Yu Zhao
2022-03-21 11:47 ` Barry Song
2022-03-09 2:12 ` [PATCH v9 06/14] mm: multi-gen LRU: minimal implementation Yu Zhao
2022-03-16 5:55 ` Huang, Ying
2022-03-16 7:54 ` Yu Zhao
2022-03-19 3:01 ` Barry Song
2022-03-19 3:11 ` Yu Zhao
2022-03-23 7:47 ` Barry Song
2022-03-24 6:24 ` Yu Zhao
2022-03-24 8:13 ` Barry Song
2022-03-19 10:14 ` Barry Song
2022-03-21 23:51 ` Yu Zhao
2022-03-19 11:15 ` Barry Song
2022-03-22 0:30 ` Yu Zhao
2022-03-21 12:51 ` Aneesh Kumar K.V
2022-03-22 4:02 ` Yu Zhao
2022-03-21 13:01 ` Aneesh Kumar K.V
2022-03-22 4:39 ` Yu Zhao
2022-03-22 5:26 ` Aneesh Kumar K.V
2022-03-22 5:55 ` Yu Zhao
2022-03-09 2:12 ` [PATCH v9 07/14] mm: multi-gen LRU: exploit locality in rmap Yu Zhao
2022-04-07 2:29 ` Barry Song
2022-04-07 3:04 ` Yu Zhao
2022-04-07 3:46 ` Barry Song
2022-04-07 23:51 ` Yu Zhao
2022-03-09 2:12 ` [PATCH v9 08/14] mm: multi-gen LRU: support page table walks Yu Zhao
2022-03-09 2:12 ` [PATCH v9 09/14] mm: multi-gen LRU: optimize multiple memcgs Yu Zhao
2022-03-09 2:12 ` [PATCH v9 10/14] mm: multi-gen LRU: kill switch Yu Zhao
2022-03-22 7:47 ` Barry Song
2022-03-22 8:20 ` Yu Zhao
2022-03-22 8:45 ` Barry Song [this message]
2022-03-22 9:00 ` Yu Zhao
2022-03-09 2:12 ` [PATCH v9 11/14] mm: multi-gen LRU: thrashing prevention Yu Zhao
2022-03-22 7:22 ` Barry Song
2022-03-22 8:14 ` Yu Zhao
2022-03-09 2:12 ` [PATCH v9 12/14] mm: multi-gen LRU: debugfs interface Yu Zhao
2022-03-09 2:12 ` [PATCH v9 13/14] mm: multi-gen LRU: admin guide Yu Zhao
2022-03-10 12:29 ` Mike Rapoport
2022-03-11 0:37 ` Yu Zhao
2022-03-09 2:12 ` [PATCH v9 14/14] mm: multi-gen LRU: design doc Yu Zhao
2022-03-11 8:22 ` Mike Rapoport
2022-03-11 9:38 ` 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=CAGsJ_4wPWRkmioxGYOwZ9KwdiJUUdgH9Xd38MJH6B2sKJNG+iA@mail.gmail.com \
--to=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=vaibhav@linux.ibm.com \
--cc=vbabka@suse.cz \
--cc=will@kernel.org \
--cc=willy@infradead.org \
--cc=x86@kernel.org \
--cc=ying.huang@intel.com \
--cc=yuzhao@google.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).