>-----Original Message----- >From: tip tree robot [mailto:bounces.tip@xxxxxxxxxxxxxxxx] On Behalf Of tip-bot for Markus Metzger >Sent: Friday, September 18, 2009 9:19 PM >To: linux-tip-commits@xxxxxxxxxxxxxxx >Cc: linux-kernel@xxxxxxxxxxxxxxx; hpa@xxxxxxxxx; mingo@xxxxxxxxxx; a.p.zijlstra@xxxxxxxxx; Metzger, >Markus T; tglx@xxxxxxxxxxxxx; mingo@xxxxxxx >Subject: [tip:perfcounters/core] x86, perf_counter, bts: Optimize BTS overflow handling > >Commit-ID: 5622f295b53fb60dbf9bed3e2c89d182490a8b7f >Gitweb: http://git.kernel.org/tip/5622f295b53fb60dbf9bed3e2c89d182490a8b7f >Author: Markus Metzger <markus.t.metzger@xxxxxxxxx> >AuthorDate: Tue, 15 Sep 2009 13:00:23 +0200 >Committer: Ingo Molnar <mingo@xxxxxxx> >CommitDate: Fri, 18 Sep 2009 20:43:20 +0200 > >x86, perf_counter, bts: Optimize BTS overflow handling > >Draining the BTS buffer on a buffer overflow interrupt takes too >long resulting in a kernel lockup when tracing the kernel. > >Restructure perf_counter sampling into sample creation and sample >output. > >Prepare a single reference sample for BTS sampling and update the >from and to address fields when draining the BTS buffer. Drain the >entire BTS buffer between a single perf_output_begin() / >perf_output_end() pair. > >Signed-off-by: Markus Metzger <markus.t.metzger@xxxxxxxxx> >Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> >LKML-Reference: <20090915130023.A16204@xxxxxxxxxxxxxxxxxxx> >Signed-off-by: Ingo Molnar <mingo@xxxxxxx> Ingo, This change should speed up BTS overflow handling enough to support branch tracing the kernel. Would you please drop 1653192f510bd8114b7b133d7289e6e5c3e95046 that disabled kernel tracing to work around the issue. thanks and 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. ��.n��������+%������w��{.n�����{��ة��)��jg��������ݢj����G�������j:+v���w�m������w�������h�����٥