Messages in this thread | | | Date | Thu, 26 Jun 2014 00:15:48 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH] sysctl: Add a feature to drop caches selectively |
| |
On Wed 2014-06-25 10:25:05, Thomas Knauth wrote: > On Wed, Jun 25, 2014 at 8:25 AM, Artem Bityutskiy <dedekind1@gmail.com> wrote: > > Plus some explanations WRT why proc-based interface and what would be > > the alternatives, what if tomorrow we want to extend the functionality > > and drop caches only for certain file range, is this only for regular > > files or also for directories, why posix_fadvice(DONTNEED) is not > > sufficient. > > I suggested the idea originally. Let me address each of your questions in turn: > > Why a selective drop? To have a middle ground between echo 2 > > drop_caches and echo 3 > drop_caches. When is this interesting? My > particular use case was benchmarking. I wanted to repeatedly measure > the timing when things were read from disk. Dropping everything from > the cache, also drops useful things, not just the few files your > benchmark intends to measure. > > Why /proc? Because this is where the current drop_caches mechanism is > located. If it should go somewhere else, please do suggest so.
It sounds like this should be a new syscall.
echoing filenames in files is strange/ugly. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
| |