On Fri, 2012-06-01 at 09:08 -0400, John Stoffel wrote: > >>>>> "Cong" == Cong Wang <amwang@xxxxxxxxxx> writes: > > Cong> Yeah, at least John Stoffel expressed his interests on this, as > Cong> a sysadmin. So I believe there are some people need it. > > I expressed an interest if there was a way to usefully *find* the > processes that are hogging cache. Without a reporting mechanism of > cache usage on per-file or per-process manner, then I don't see a > great use for this. It's just simpler to drop all the caches when you > hit a wall. > > Cong> Now the problem is that I don't find a proper existing utility > Cong> to patch, maybe Pádraig has any hints on this? Could this > Cong> feature be merged into some core utility? Or I have to write a > Cong> new utility for this? > > I'd write a new tutorial utility, maybe you could call it 'cache_top' > and have it both show the biggest users of cache, as well as exposing > your new ability to drop the cache on a per-fd basis. > > It's really not much use unless we can measure it. Fair enough. We could do that with Keiichi's page cache tracepoint patches: https://lkml.org/lkml/2011/7/18/326 with that patch, we can measure page caches with `perf`. I tried to carry Keiichi's patches, but those patch depend on other patches too, the main problem is still translating the inode number to file name for user-space users to read, which is not trivial at all. Also, will vmtouch work for you too? You can get it at http://hoytech.com/vmtouch/ I can patch it too if you want. Thanks! -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
