From: Chunyu Hu <chuhu@redhat.com>
To: linux-mm@kvack.org
Cc: hannes@cmpxchg.org, guro@fb.com, akpm@linux-foundation.org
Subject: Question about admin_reserve_kbytes in GUESS mode
Date: Tue, 15 Dec 2020 06:42:39 -0500 (EST) [thread overview]
Message-ID: <1273738630.62467759.1608032559889.JavaMail.zimbra@redhat.com> (raw)
In-Reply-To: <223826327.62466770.1608031937021.JavaMail.zimbra@redhat.com>
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Hello experts,
I find admin_reserve_kbytes is not working as documented since
commit 8c7829b04c523cdc(mm: fix false-positive OVERCOMMIT_GUESS failures).
Before that, available free pages are used to determine the allocation check, and admin_reserve_kbytes
was honored in the default GUESS over_commit mode. While after that commit, admin_reserve_kbytes
is not honored in default mode any more. This looks like break the sysctl usage?
Documentation/admin-guide/sysctl/vm.rst:
admin_reserve_kbytes
====================
The amount of free memory in the system that should be reserved for users
with the capability cap_sys_admin.
admin_reserve_kbytes defaults to min(3% of free pages, 8MB)
That should provide enough for the admin to log in and kill a process,
if necessary, under the default overcommit 'guess' mode.
.......
--
Regards,
Chunyu Hu
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next parent reply other threads:[~2020-12-15 11:42 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <223826327.62466770.1608031937021.JavaMail.zimbra@redhat.com>
2020-12-15 11:42 ` Chunyu Hu [this message]
2020-12-15 13:06 ` Johannes Weiner
2020-12-16 16:37 ` Chunyu Hu
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