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[71.184.117.43]) by smtp.gmail.com with ESMTPSA id j17sm10884571qta.0.2019.09.30.16.49.19 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 30 Sep 2019 16:49:19 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable From: Qian Cai Mime-Version: 1.0 (1.0) Subject: Re: [PATCH v2 2/3] mm, page_owner: decouple freeing stack trace from debug_pagealloc Date: Mon, 30 Sep 2019 19:49:18 -0400 Message-Id: <731C4866-DF28-4C96-8EEE-5F22359501FE@lca.pw> References: Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, "Kirill A. Shutemov" , Matthew Wilcox , Mel Gorman , Michal Hocko , Dmitry Vyukov , Walter Wu , Andrey Ryabinin In-Reply-To: To: Vlastimil Babka X-Mailer: iPhone Mail (17A844) 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: > On Sep 30, 2019, at 5:43 PM, Vlastimil Babka wrote: >=20 > Well, my use case is shipping production kernels with CONFIG_PAGE_OWNER > and CONFIG_DEBUG_PAGEALLOC enabled, and instructing users to boot-time > enable only for troubleshooting a crash or memory leak, without a need > to install a debug kernel. Things like static keys and page_ext > allocations makes this possible without CPU and memory overhead when not > boot-time enabled. I don't know too much about KASAN internals, but I > assume it's not possible to use it that way on production kernels yet? In that case, why can=E2=80=99t users just simply enable page_owner=3Don and= debug_pagealloc=3Don for troubleshooting? The later makes the kernel slower= , but I am not sure if it is worth optimization by adding a new parameter. T= here have already been quite a few MM-related kernel parameters that could t= idy up a bit in the future.=