[tip:perf/urgent] perf: Fix Pentium4 raw event validation

From: tip-bot for Stephane Eranian
Date: Wed Jan 26 2011 - 02:26:32 EST


Commit-ID: 3284063535adb5ca02e7ad51d7556193fb8e799e
Gitweb: http://git.kernel.org/tip/3284063535adb5ca02e7ad51d7556193fb8e799e
Author: Stephane Eranian <eranian@xxxxxxxxxx>
AuthorDate: Tue, 25 Jan 2011 17:32:01 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Wed, 26 Jan 2011 08:01:20 +0100

perf: Fix Pentium4 raw event validation

This patch fixes some issues with raw event validation on
Pentium 4 (Netburst) based processors.

As I was testing libpfm4 Netburst support, I ran into two
problems in the p4_validate_raw_event() function:

- the shared field must be checked ONLY when HT is on
- the binding to ESCR register was missing

The second item was causing raw events to not be encoded
correctly compared to generic PMU events.

With this patch, I can now pass Netburst events to libpfm4
examples and get meaningful results:

$ task -e global_power_events:running:u noploop 1
noploop for 1 seconds
3,206,304,898 global_power_events:running

Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
Acked-by: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: peterz@xxxxxxxxxxxxx
Cc: paulus@xxxxxxxxx
Cc: davem@xxxxxxxxxxxxx
Cc: fweisbec@xxxxxxxxx
Cc: perfmon2-devel@xxxxxxxxxxxx
Cc: eranian@xxxxxxxxx
Cc: robert.richter@xxxxxxx
Cc: acme@xxxxxxxxxx
Cc: gorcunov@xxxxxxxxx
Cc: ming.m.lin@xxxxxxxxx
LKML-Reference: <4d3efb2f.1252d80a.1a80.ffffc83f@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/cpu/perf_event_p4.c | 12 ++++++++++--
1 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index e56b9bf..f7a0993 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -682,7 +682,7 @@ static int p4_validate_raw_event(struct perf_event *event)
* if an event is shared accross the logical threads
* the user needs special permissions to be able to use it
*/
- if (p4_event_bind_map[v].shared) {
+ if (p4_ht_active() && p4_event_bind_map[v].shared) {
if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
return -EACCES;
}
@@ -727,7 +727,8 @@ static int p4_hw_config(struct perf_event *event)
event->hw.config = p4_set_ht_bit(event->hw.config);

if (event->attr.type == PERF_TYPE_RAW) {
-
+ struct p4_event_bind *bind;
+ unsigned int esel;
/*
* Clear bits we reserve to be managed by kernel itself
* and never allowed from a user space
@@ -743,6 +744,13 @@ static int p4_hw_config(struct perf_event *event)
* bits since we keep additional info here (for cache events and etc)
*/
event->hw.config |= event->attr.config;
+ bind = p4_config_get_bind(event->attr.config);
+ if (!bind) {
+ rc = -EINVAL;
+ goto out;
+ }
+ esel = P4_OPCODE_ESEL(bind->opcode);
+ event->hw.config |= p4_config_pack_cccr(P4_CCCR_ESEL(esel));
}

rc = x86_setup_perfctr(event);
--
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