From: Brian Masney <bmasney@redhat.com>
To: Jonathan Corbet <corbet@lwn.net>,
	 Shuah Khan <skhan@linuxfoundation.org>,
	 Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org, linux-doc@vger.kernel.org,
	 linux-kernel@vger.kernel.org, Matthew Storr <mstorr@redhat.com>,
	 Brian Masney <bmasney@redhat.com>
Subject: [PATCH] docs: mm: clarify that user_reserve_kbytes has no effect when overcommit_memory is set to 0 or 1
Date: Thu, 28 May 2026 09:45:10 -0400	[thread overview]
Message-ID: <20260528-mm-clarify-docs-v1-1-aa88e83b4bfd@redhat.com> (raw)

Looking at __vm_enough_memory() in mm/util.c, user_reserve_kbytes has no
effect when overcommit_memory is set to 0 or 1. The documentation for
overcommit_memory already references user_reserve_kbytes when the flag
is set to 2.

Let's go ahead and add a clarification to user_reserve_kbytes in vm.rst
that it has no effect when overcommit_memory is set to 0 or 1.

Signed-off-by: Brian Masney <bmasney@redhat.com>
---
 Documentation/admin-guide/sysctl/vm.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst
index 97e12359775c..b9b0c218bfb4 100644
--- a/Documentation/admin-guide/sysctl/vm.rst
+++ b/Documentation/admin-guide/sysctl/vm.rst
@@ -1034,6 +1034,8 @@ min(3% of current process size, user_reserve_kbytes) of free memory.
 This is intended to prevent a user from starting a single memory hogging
 process, such that they cannot recover (kill the hog).
 
+This setting has no effect when overcommit_memory is set to 0 or 1.
+
 user_reserve_kbytes defaults to min(3% of the current process size, 128MB).
 
 If this is reduced to zero, then the user will be allowed to allocate

---
base-commit: e7d700e14934e68f86338c5610cf2ae76798b663
change-id: 20260528-mm-clarify-docs-76ab8f82826d

Best regards,
-- 
Brian Masney <bmasney@redhat.com>

next             reply	other threads:[~2026-05-28 13:45 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-28 13:45 Brian Masney [this message]
2026-05-28 14:02 ` [PATCH] docs: mm: clarify that user_reserve_kbytes has no effect when overcommit_memory is set to 0 or 1 Brian Masney

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