On Mon, 15 Nov 2010 19:10:06 +0100 Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote: > On Mon, 2010-11-15 at 19:00 +0100, Martin Schwidefsky wrote: > > On Mon, 15 Nov 2010 18:51:57 +0100 > > Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> wrote: > > > > > On Mon, 2010-11-15 at 18:49 +0100, Martin Schwidefsky wrote: > > > > > To what purpose? > > > > > > > > Is that a trick question? Why do we have tools like "top"? Or process > > > > accounting? The point is that the quality of the numbers we get right > > > > now is rather bad, the overhead of scanning /proc is horrendous and > > > > the 10ms granularity is rather coarse. > > > > > > But you're not just replacing top, you're adding all kinds of new > > > accounting crap all over the place. > > > > We DO replace top. Patch #7 of 7. > > You _also_ replace top, but its not by far the only thing you do. If you > simply replaced top you wouldn't need to add tons of extra accounting, > would you? There are basically two things we want to accomplish: 1) Make top faster by replacing the /proc based data gathering with taskstats. To really make it go fast with taskstats we filter with last_depart to read only tasks that have changed since the last snapshot. 2) Make top more precise. That is where all of the extra accounting comes into play. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
