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bh=FbJxtBRUzaq14tEYegaKum4NxMdFUr/7vbSSHB92jDo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Hy3P94XFDUXk6tU9GNq5CIL9vpL5JIYIqJxo5Dddl4Lyni2Z2dqfmtSz7120G69az jYGFL76aKiodXvYN3OVrzPyfesEB+Um0xxKOQeANvgv19bpPIw6aRwaOOF9SzjT9kJ ijB/52AFaeXBreAiDELLWQHFMElZ1lGk/T3KkQD4= Date: Mon, 3 Aug 2026 14:44:22 +0100 From: Catalin Marinas To: Breno Leitao Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH] mm: kmemleak: default min_unref_scans to 2 for verbose auto-scan Message-ID: References: <20260730-kmemleak_hardened-v1-1-b0b20033b4bb@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: B037880010 X-Stat-Signature: qhnudkxmj1rk4u1ysc7rfxoma63kjdor X-HE-Tag: 1785764670-12013 X-HE-Meta: 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 I+mKWA35 3p1nhrJZ53IfFXbeEII31KZKIl4yapMypEWAlpmi90KVT79VODhu3z8ia4ds0yj3A1/g26EWiu42WIb1p2+kDLIvAvM5zlzfZRCjnbKWOSRf+YXO7jzOrZ5JKwG26V4gMXG2Fgg9mY5+ZNXwRsWj2E2cvP/ZuXQLr+cdCvBWeuYGdTY8Ru5JnIL6TA+zVedmSOBUcxwp40Fly8lAFl1CBqsXFuwfCs1sBvsIRcH9IiUPJ+C/amIPnBT/RCs5qWb7gcQhlnFgu8utCk7hY00KWloWxoxzprNHXQyXhXNPblTZwfGydAIq39eYDQvPjGKd+GX5JkFexsvSR0i6rIwnZKwe0qjrNR/Vnr5zIw6ewQXBuhOQ= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Aug 03, 2026 at 02:41:20PM +0100, Catalin Marinas wrote: > On Thu, Jul 30, 2026 at 07:31:21AM -0700, Breno Leitao wrote: > > min_unref_scans defers reporting an object as leaked until it has stayed > > unreferenced for that many consecutive scans, filtering out objects that > > are only transiently unreferenced during a scan. > > > > It defaults to 1, which reports on the first unreferenced scan. > > > > When CONFIG_DEBUG_KMEMLEAK_AUTO_SCAN and CONFIG_DEBUG_KMEMLEAK_VERBOSE are > > both enabled, the scan thread runs periodically and the user has opted into > > detailed leak reporting, so a second confirming scan happens on its own. > > > > Default min_unref_scans to 2 in that configuration to suppress transient > > false positives. > > > > Keep the default at 1 otherwise, where a manually triggered scan is > > expected to report immediately. The value stays writable through the module > > parameter. > > > > Signed-off-by: Breno Leitao > > Acked-by: Catalin Marinas Ah, I noticed there's a v2. Ignore this one. -- Catalin