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Fri, 28 Apr 2023 09:14:24 -0700 (PDT) MIME-Version: 1.0 References: <20230427153345.451d86681f9c6775ea579e5a@linux-foundation.org> In-Reply-To: From: Suren Baghdasaryan Date: Fri, 28 Apr 2023 09:14:12 -0700 Message-ID: Subject: Re: [GIT PULL] MM updates for 6.4-rc1 To: Linus Torvalds Cc: Andrew Morton , mm-commits@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Lorenzo Stoakes , Vlastimil Babka Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspam-User: X-Rspamd-Queue-Id: C7C0040010 X-Rspamd-Server: rspam01 X-Stat-Signature: 51hdsffkkaia9eca3g6z6p3inymg5hfj X-HE-Tag: 1682698465-664838 X-HE-Meta: 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 94Clz4zv cOi3jOetToG8DpTTd5OLYCWWHllrFIRDy7CHLRqsl6Mz/4xDRrbKmqo594pk5J9XoQXqN+arROWU2SKiQxwVpkId0cucOf8gpHiu5qS9A30HyLRqh8qaKXLswJUTmZXjlC78/zfvpysa9Imy2IPc5gPgGD8xiXQvsC0cDckFEShkQlgk9izc6bG0LvkaDMfzfzeJ0cjNvrlvC8VfA3pzdrsG86HNj5ttKZmP0WRql02EoReaTpCvRsBlpH7+CsyOz1ssts9Lr7HMa49YB83kV15fdcE+pEQ1MacnWJTmMtEYUXilB7w9Ca9UzxA== 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 Fri, Apr 28, 2023 at 9:08=E2=80=AFAM Linus Torvalds wrote: > > On Fri, Apr 28, 2023 at 9:03=E2=80=AFAM Suren Baghdasaryan wrote: > > > > I wanted these stats enabled by default to be able to identify > > possible pathological cases and to also let users disable them if they > > can't tolerate even a small overhead in the pagefault path. Should I > > document this reasoning for the config option? > > You should document what the stats actually count (at a high enough > level for a user to understand), and why anybody would want to keep > them on. > > Honestly, 99% of the time, these are things that *developers* think > they might want, but that nobody else will ever ever use. > > Really, ask yourself if a normal user would ever look at them? > > Now, ask yourself whether this might be something that a cloud > provider would want to look at to gather statistics. > > And if it's the latter case, then it should be "default n", because > the default should be for the people who DO NOT KNOW, AND DO NOT CARE. > > The cloud provider will be using a custom config anyway. The default > is irrelevant for that use. The use that *matters* is literally the > clueless end user who I bet will never look at these numbers, and will > never be asked for them. Ok, sounds like this should be 'default n'. I'll prepare a patch. Thanks! > > Linus