From: Daniel Qarras Date: Sun, 12 Jul 2009 11:32:40 +0000 (-0700) Subject: perf_counter, x86: Extend perf_counter Pentium M support X-Git-Tag: v2.6.31-rc4~3^2~12^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f1c6a58121f9846ac665b0fbd3cbab90ce8bcbac;p=pandora-kernel.git perf_counter, x86: Extend perf_counter Pentium M support I've attached a patch to remove the Pentium M special casing of EMON and as noticed at least with my Pentium M the hardware PMU now works: Performance counter stats for '/bin/ls /var/tmp': 1.809988 task-clock-msecs # 0.125 CPUs 1 context-switches # 0.001 M/sec 0 CPU-migrations # 0.000 M/sec 224 page-faults # 0.124 M/sec 1425648 cycles # 787.656 M/sec 912755 instructions # 0.640 IPC Vince suggested that this code was trying to address erratum Y17 in Pentium-M's: http://download.intel.com/support/processors/mobile/pm/sb/25266532.pdf But that erratum (related to IA32_MISC_ENABLES.7) does not affect perfcounters as we dont use this toggle to disable RDPMC and WRMSR/RDMSR access to performance counters. We keep cr4's bit 8 (X86_CR4_PCE) clear so unprivileged RDPMC access is not allowed anyway. Cc: Vince Weaver Cc: Peter Zijlstra Cc: Stephane Eranian LKML-Reference: Signed-off-by: Ingo Molnar --- Reading git-diff-tree failed