The patch titled
Subject: mm: multi-gen LRU: section for working set protection
has been added to the -mm mm-unstable branch. Its filename is
mm-multi-gen-lru-section-for-working-set-protection.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-multi-gen-lru-section-for-working-set-protection.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: "T.J. Alumbaugh" <talumbau@xxxxxxxxxx>
Subject: mm: multi-gen LRU: section for working set protection
Date: Wed, 18 Jan 2023 00:18:21 +0000
Patch series "mm: multi-gen LRU: improve".
This patch series improves a few MGLRU functions, collects related
functions, and adds additional documentation.
This patch (of 7):
Add a section for working set protection in the code and the design doc.
The admin doc already contains its usage.
Link: https://lkml.kernel.org/r/20230118001827.1040870-1-talumbau@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20230118001827.1040870-2-talumbau@xxxxxxxxxx
Signed-off-by: T.J. Alumbaugh <talumbau@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/Documentation/mm/multigen_lru.rst~mm-multi-gen-lru-section-for-working-set-protection
+++ a/Documentation/mm/multigen_lru.rst
@@ -141,6 +141,21 @@ loop has detected outlying refaults from
this end, the feedback loop uses the first tier as the baseline, for
the reason stated earlier.
+Working set protection
+----------------------
+Each generation is timestamped at birth. If ``lru_gen_min_ttl`` is
+set, an ``lruvec`` is protected from the eviction when its oldest
+generation was born within ``lru_gen_min_ttl`` milliseconds. In other
+words, it prevents the working set of ``lru_gen_min_ttl`` milliseconds
+from getting evicted. The OOM killer is triggered if this working set
+cannot be kept in memory.
+
+This time-based approach has the following advantages:
+
+1. It is easier to configure because it is agnostic to applications
+ and memory sizes.
+2. It is more reliable because it is directly wired to the OOM killer.
+
Summary
-------
The multi-gen LRU can be disassembled into the following parts:
--- a/mm/vmscan.c~mm-multi-gen-lru-section-for-working-set-protection
+++ a/mm/vmscan.c
@@ -4475,6 +4475,10 @@ done:
return true;
}
+/******************************************************************************
+ * working set protection
+ ******************************************************************************/
+
static bool lruvec_is_sizable(struct lruvec *lruvec, struct scan_control *sc)
{
int gen, type, zone;
_
Patches currently in -mm which might be from talumbau@xxxxxxxxxx are
mm-multi-gen-lru-section-for-working-set-protection.patch
mm-multi-gen-lru-section-for-rmap-pt-walk-feedback.patch
mm-multi-gen-lru-section-for-bloom-filters.patch
mm-multi-gen-lru-section-for-memcg-lru.patch
mm-multi-gen-lru-improve-lru_gen_exit_memcg.patch
mm-multi-gen-lru-improve-walk_pmd_range.patch
mm-multi-gen-lru-simplify-lru_gen_look_around.patch
