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AJvYcCXZBUrgqLvY/aB7bCp4oKfseI8Cyq8/bOoKE9u3NTxN4+kem8c6VBlI7eMGDEmOyc/bf4noqaptC7Gomdd6xmhi9kk= X-Gm-Message-State: AOJu0Yx8qCSxs5O4yHF/iMUW9y2ViszMdSf3rLa48uPjVYLzW/Pj8Jog uBsU+f75kLQEoq/SY5h4sWZczw/ouD17YqjBfQII7BHTSKuT5n3yZUZlncEa5+fq9ScInxxrxxY UAWVuwc2SJB+3KUf0iN0W8wD1mY0= X-Google-Smtp-Source: AGHT+IFFYy1A3RqdZ6XL4FzBiAcL85PGmQ+hHNlwWS1uWXR26y82VIzYROzLkKq18dxpwInUHrMk3RTnju/jtSmahRM= X-Received: by 2002:a05:6808:10cf:b0:3d6:362b:5ea3 with SMTP id 5614622812f47-3d6362b6505mr181081b6e.14.1719592951763; Fri, 28 Jun 2024 09:42:31 -0700 (PDT) MIME-Version: 1.0 References: <20240627170900.1672542-1-andrii@kernel.org> <20240627125938.da3541c6babfe046f955df7a@linux-foundation.org> <20240627141126.2ce3b4981e4f580713e31be0@linux-foundation.org> In-Reply-To: <20240627141126.2ce3b4981e4f580713e31be0@linux-foundation.org> From: Andrii Nakryiko Date: Fri, 28 Jun 2024 09:42:19 -0700 Message-ID: Subject: Re: [PATCH v6 0/6] ioctl()-based API to query VMAs from /proc//maps To: Andrew Morton Cc: Andrii Nakryiko , linux-fsdevel@vger.kernel.org, brauner@kernel.org, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, gregkh@linuxfoundation.org, linux-mm@kvack.org, liam.howlett@oracle.com, surenb@google.com, rppt@kernel.org, adobriyan@gmail.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: DD49F1A000F X-Stat-Signature: a77d8dq5a81edxf7qzn5bbzuqxxifr7p X-Rspam-User: X-HE-Tag: 1719592952-196233 X-HE-Meta: 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 WAJAbMAP hdSNv36Ox5TrI51p3OlE3PWAlZmK1WGrrck+5DpmuWtOWoPXAtl0MyTGQD9KmZOuFHG/qXP2V3WWajIAZA1xNcQhZA8dxqpcmZZGUy4L/D5sgjSZzTqgJMrF8Td9Go15FriA3glpt9TRmsKJCYRbj1NLoFBmhMQaJdgK/TcZNO85h9WVByYlT0aALg8xqvxiUhQvNue7rmPIrtzS8x1CQ2RZWjuHkfgwjgjR/JRnWmzgmkMon3yjavBUHEDiGc6Gr9TYy+1xCOqtwikmATKxA02MqQKZvyGGap3uSgWZkg6qWm7DagqIrcJUwh4tVj9QJeHH7sRGRKE3tMaYeqzQMaMqTZasIh8gsFoKVnuE0LUvEUMEalsqjRd7OIO8vHI6Bs32Zypuqi71G3nY92pY7qaNebimNCbRnaINc 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: On Thu, Jun 27, 2024 at 2:11=E2=80=AFPM Andrew Morton wrote: > > On Thu, 27 Jun 2024 13:50:22 -0700 Andrii Nakryiko wrote: > > > On Thu, Jun 27, 2024 at 12:59=E2=80=AFPM Andrew Morton > > > Is it possible/sensible to make this feature Kconfigurable so that pe= ople who > > > don't need it can omit it? > > > > It's just a matter of #ifdef/#endif, so not hard, technically > > speaking. But I'm wondering what's the concern? This is mostly newly > > added code (except factoring out get_vma_name logic, which won't be > > #ifdef'ed anyways), so if no one is using this new API, then it should > > cause no issue. > > > > Generally speaking, I'd say if we don't *have to* add the Kconfig > > option, I'd prefer that. But if you feel strongly, it's not hard for > > me to do, of course. > > > > Or are you concerned with the vmlinux code size increase? It doesn't > > seem to be large enough to warrant a Kconfig, IMO (from > > bloat-o-meter): > > > > do_procmap_query - 1308 +1308 > > get_vma_name - 283 +283 > > procfs_procmap_ioctl - 47 +47 > > show_map_vma 444 274 -170 > > > > But again, do let me know if you insist. > > Yes, I'm thinking about being nice to small systems ("make > tinyconfig"!). The kernel just gets bigger and bigger over time, > little bit by little bit. > > It's a judgment call - if making it configurable is ugly and/or adds > maintenance overhead then no. > I see, thanks for clarifying. I'd vote to not add extra Kconfig to keep things simple and less surprising. All this code is conditional on CONFIG_PROC_FS=3Dy anyways, and there is plenty of code for procfs already. I think this do_procmap_query is just a small addition here that doesn't fundamentally regress anything.