Messages in this thread | | | From | "Metzger, Markus T" <> | Date | Tue, 18 Aug 2009 14:20:30 +0100 | Subject | RE: [PATCH] perf_counter: Fix a race on perf_counter_ctx |
| |
>-----Original Message----- >From: Peter Zijlstra [mailto:peterz@infradead.org] >Sent: Tuesday, August 18, 2009 3:00 PM >To: Metzger, Markus T >Cc: Ingo Molnar; tglx@linutronix.de; hpa@zytor.com; markus.t.metzger@gmail.com; linux- >kernel@vger.kernel.org; Paul Mackerras >Subject: RE: [PATCH] perf_counter: Fix a race on perf_counter_ctx > >On Tue, 2009-08-18 at 14:59 +0200, Peter Zijlstra wrote: >> On Tue, 2009-08-18 at 13:49 +0100, Metzger, Markus T wrote: >> > Hi Ingo, Peter, >> > >> > Did you say that branch tracing is working for you? >> > >> > On my system, the kernel hangs. >> > >> > Could it be that it simply takes too long to copy the trace? When I set the number >> > of samples to 10, everything seems to work OK. When I increase that number to 1000, >> > the kernel is getting very slow and eventually hangs. >> > >> > I get a message "hrtimer: interrupt too slow", and I get a soft lockup bug. The rest >> > of the message log seems pretty garbled. > >How many NMI/s is this generating anyway?
One every 800 or so branches in the current configuration - which results in 800 plus a few perf_counter_output() calls per interrupt.
regards, markus. --------------------------------------------------------------------- Intel GmbH Dornacher Strasse 1 85622 Feldkirchen/Muenchen Germany Sitz der Gesellschaft: Feldkirchen bei Muenchen Geschaeftsfuehrer: Douglas Lusk, Peter Gleissner, Hannes Schwaderer Registergericht: Muenchen HRB 47456 Ust.-IdNr. VAT Registration No.: DE129385895 Citibank Frankfurt (BLZ 502 109 00) 600119052
This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). Any review or distribution by others is strictly prohibited. If you are not the intended recipient, please contact the sender and delete all copies.
| |