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([121.232.96.69]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-201f0319683sm61362135ad.67.2024.08.19.04.36.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Aug 2024 04:36:27 -0700 (PDT) From: Vernon Yang To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Vernon Yang Subject: [PATCH] mm/util: Fix meminfo CommitLimit Date: Mon, 19 Aug 2024 19:36:19 +0800 Message-Id: <20240819113619.1267937-1-vernon2gm@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On a machine with 8GB memory, no any swap device, the /proc/meminfo CommitLimit shows 4070944KB regardless of overcommit_memory being set to 0/1/2. This patch fixes this bug, and the final effect is as follows: - when overcommit_memory being set to 0 ## OVERCOMMIT_GUESS CommitLimit: 8141884 kB - when overcommit_memory being set to 1 ## OVERCOMMIT_ALWAYS CommitLimit: 0 kB - when overcommit_memory being set to 2 ## OVERCOMMIT_NEVER and overcommit_ratio 50 CommitLimit: 4070940 kB Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Vernon Yang --- mm/util.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/mm/util.c b/mm/util.c index bd283e2132e0..4ee93c11dd62 100644 --- a/mm/util.c +++ b/mm/util.c @@ -932,12 +932,21 @@ int overcommit_kbytes_handler(const struct ctl_table = *table, int write, void *bu } =20 /* - * Committed memory limit enforced when OVERCOMMIT_NEVER policy is used + * Committed virtual memory limit + * + * return 0 if OVERCOMMIT_ALWAYS policy is used, otherwise return committed + * memory limit enforced if OVERCOMMIT_GUESS or OVERCOMMIT_NEVER policy is= used. */ unsigned long vm_commit_limit(void) { unsigned long allowed; =20 + if (sysctl_overcommit_memory =3D=3D OVERCOMMIT_ALWAYS) + return 0; + + if (sysctl_overcommit_memory =3D=3D OVERCOMMIT_GUESS) + return totalram_pages() + total_swap_pages; + if (sysctl_overcommit_kbytes) allowed =3D sysctl_overcommit_kbytes >> (PAGE_SHIFT - 10); else base-commit: 47ac09b91befbb6a235ab620c32af719f8208399 --=20 2.34.1