From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH v4 1/5] mm/page_idle: Add per-pid idle page tracking using virtual indexing Date: Wed, 7 Aug 2019 13:01:22 -0700 Message-ID: <20190807130122.f148548c05ec07e7b716457e@linux-foundation.org> References: <20190805170451.26009-1-joel@joelfernandes.org> <20190806151921.edec128271caccb5214fc1bd@linux-foundation.org> <20190807100013.GC169551@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190807100013.GC169551@google.com> Sender: linux-kernel-owner@vger.kernel.org To: Joel Fernandes Cc: linux-kernel@vger.kernel.org, Alexey Dobriyan , Borislav Petkov , Brendan Gregg , Catalin Marinas , Christian Hansen , dancol@google.com, fmayer@google.com, "H. Peter Anvin" , Ingo Molnar , Jonathan Corbet , Kees Cook , kernel-team@android.com, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, Michal Hocko , Mike Rapoport , minchan@kernel.org, namhyung@google.com, paulmck@linux.ibm.com, Robin Murphy , Roman Gushchin , Stephen Rothwell List-Id: linux-api@vger.kernel.org On Wed, 7 Aug 2019 06:00:13 -0400 Joel Fernandes wrote: > > > 8 files changed, 376 insertions(+), 45 deletions(-) > > > > Quite a lot of new code unconditionally added to major architectures. > > Are we confident that everyone will want this feature? > > I did not follow, could you clarify more? All of this diff stat is not to > architecture code: My point is that the patchset adds a lot of new code with no way in which users can opt out. Almost everyone gets a fatter kernel - how many of those users will actually benefit from it? If "not many" then shouldn't we be making it Kconfigurable? Are there userspace tools which present this info to users or which provide monitoring of some form? Do major distros ship those tools? Do people use them? etcetera.