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AJvYcCWK15k7boFz7k1YJj8RTrqSWSaDgnKhtYZKXNC6TwbAVvrJbEp2W7IUAo7pkmzigPHRzCaC6HWTbQ==@kvack.org X-Gm-Message-State: AOJu0YxaB0MhiX/NgNefjMnqqKB2154zadKn6t6lznIq6Frfbe7Aeobr GUKcoeRU4CzxP6nO1VE3L5BrbgAAeVnuxmCv5apIbBREXA4smga6YV/QgntVhVRi57tmO7gzTkN M85BQgg== X-Received: from dybb6.prod.google.com ([2002:a05:693c:6086:b0:2a2:4eb1:3771]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7301:688:b0:2ac:2480:f0ac with SMTP id 5a478bee46e88-2b48f5bac9emr4987449eec.23.1768455961332; Wed, 14 Jan 2026 21:46:01 -0800 (PST) Date: Wed, 14 Jan 2026 21:45:57 -0800 Mime-Version: 1.0 X-Mailer: git-send-email 2.52.0.457.g6b5491de43-goog Message-ID: <20260115054557.2127777-1-surenb@google.com> Subject: [PATCH 1/1] Docs/mm/allocation-profiling: describe sysctrl limitations in debug mode From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: kent.overstreet@linux.dev, corbet@lwn.net, ranxiaokai627@163.com, ran.xiaokai@zte.com.cn, surenb@google.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: C068840005 X-Stat-Signature: 685wphpuftheg6x6f3wdtsar43qdfcex X-Rspam-User: X-Rspamd-Server: rspam05 X-HE-Tag: 1768455962-836047 X-HE-Meta: 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 8OBJhg9u 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: When CONFIG_MEM_ALLOC_PROFILING_DEBUG=y, /proc/sys/vm/mem_profiling is read-only to avoid debug warnings in a scenario when an allocation is made while profiling is disabled (allocation does not get an allocation tag), then profiling gets enabled and allocation gets freed (warning due to the allocation missing allocation tag). Fixes: ebdf9ad4ca98 ("memprofiling: documentation") Reported-by: Andrew Morton Signed-off-by: Suren Baghdasaryan Cc: stable@vger.kernel.org --- Documentation/admin-guide/sysctl/vm.rst | 4 ++++ Documentation/mm/allocation-profiling.rst | 10 ++++++++++ 2 files changed, 14 insertions(+) diff --git a/Documentation/admin-guide/sysctl/vm.rst b/Documentation/admin-guide/sysctl/vm.rst index 9096e2d77c2a..8577ea91e226 100644 --- a/Documentation/admin-guide/sysctl/vm.rst +++ b/Documentation/admin-guide/sysctl/vm.rst @@ -487,6 +487,10 @@ memory allocations. The default value depends on CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT. +When CONFIG_MEM_ALLOC_PROFILING_DEBUG=y, this control is read-only to avoid +warnings produces by allocations made while profiling is disabled and freed +when it's enabled. + memory_failure_early_kill ========================= diff --git a/Documentation/mm/allocation-profiling.rst b/Documentation/mm/allocation-profiling.rst index 316311240e6a..058d2faffb75 100644 --- a/Documentation/mm/allocation-profiling.rst +++ b/Documentation/mm/allocation-profiling.rst @@ -33,6 +33,16 @@ Boot parameter: sysctl: /proc/sys/vm/mem_profiling + 1: Enable memory profiling. + + 0: Disable memory profiling. + + The default value depends on CONFIG_MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT. + + When CONFIG_MEM_ALLOC_PROFILING_DEBUG=y, this control is read-only to avoid + warnings produces by allocations made while profiling is disabled and freed + when it's enabled. + Runtime info: /proc/allocinfo base-commit: 560d6a4c4951ae76b5c6d5b5b8650276706f68ac -- 2.52.0.457.g6b5491de43-goog