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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-05-25 17:49:05 +0200
committerIngo Molnar <mingo@elte.hu>2010-06-09 11:12:34 +0200
commit8d2cacbbb8deadfae78aa16e4e1ee619bdd7019e (patch)
tree79fcb319d1c99e348b0a04056e016c85c3666b35 /include/linux/perf_event.h
parent3af9e859281bda7eb7c20b51879cf43aa788ac2e (diff)
downloadlwn-8d2cacbbb8deadfae78aa16e4e1ee619bdd7019e.tar.gz
lwn-8d2cacbbb8deadfae78aa16e4e1ee619bdd7019e.zip
perf: Cleanup {start,commit,cancel}_txn details
Clarify some of the transactional group scheduling API details and change it so that a successfull ->commit_txn also closes the transaction. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1274803086.5882.1752.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/perf_event.h')
-rw-r--r--include/linux/perf_event.h27
1 files changed, 22 insertions, 5 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 36efad90cd43..f1b6ba0770e0 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -549,7 +549,10 @@ struct hw_perf_event {
struct perf_event;
-#define PERF_EVENT_TXN_STARTED 1
+/*
+ * Common implementation detail of pmu::{start,commit,cancel}_txn
+ */
+#define PERF_EVENT_TXN 0x1
/**
* struct pmu - generic performance monitoring unit
@@ -563,14 +566,28 @@ struct pmu {
void (*unthrottle) (struct perf_event *event);
/*
- * group events scheduling is treated as a transaction,
- * add group events as a whole and perform one schedulability test.
- * If test fails, roll back the whole group
+ * Group events scheduling is treated as a transaction, add group
+ * events as a whole and perform one schedulability test. If the test
+ * fails, roll back the whole group
*/
+ /*
+ * Start the transaction, after this ->enable() doesn't need
+ * to do schedulability tests.
+ */
void (*start_txn) (const struct pmu *pmu);
- void (*cancel_txn) (const struct pmu *pmu);
+ /*
+ * If ->start_txn() disabled the ->enable() schedulability test
+ * then ->commit_txn() is required to perform one. On success
+ * the transaction is closed. On error the transaction is kept
+ * open until ->cancel_txn() is called.
+ */
int (*commit_txn) (const struct pmu *pmu);
+ /*
+ * Will cancel the transaction, assumes ->disable() is called for
+ * each successfull ->enable() during the transaction.
+ */
+ void (*cancel_txn) (const struct pmu *pmu);
};
/**