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authorSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>2015-09-03 20:07:45 -0700
committerIngo Molnar <mingo@kernel.org>2015-09-13 11:27:25 +0200
commitfbbe07011581990ef74dfac06dc8511b1a14badb (patch)
tree8b026523a68ff8d98107a393d0551c9bfbf00812 /include/linux
parent845583767c306dac0290aab908c18b01772ea4b4 (diff)
downloadblackbird-op-linux-fbbe07011581990ef74dfac06dc8511b1a14badb.tar.gz
blackbird-op-linux-fbbe07011581990ef74dfac06dc8511b1a14badb.zip
perf/core: Add a 'flags' parameter to the PMU transactional interfaces
Currently, the PMU interface allows reading only one counter at a time. But some PMUs like the 24x7 counters in Power, support reading several counters at once. To leveage this functionality, extend the transaction interface to support a "transaction type". The first type, PERF_PMU_TXN_ADD, refers to the existing transactions, i.e. used to _schedule_ all the events on the PMU as a group. A second transaction type, PERF_PMU_TXN_READ, will be used in a follow-on patch, by the 24x7 counters to read several counters at once. Extend the transaction interfaces to the PMU to accept a 'txn_flags' parameter and use this parameter to ignore any transactions that are not of type PERF_PMU_TXN_ADD. Thanks to Peter Zijlstra for his input. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> [peterz: s390 compile fix] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1441336073-22750-3-git-send-email-sukadev@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/perf_event.h14
1 files changed, 11 insertions, 3 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index d61ee4459eee..ea3b5dd21a4c 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -201,6 +201,8 @@ struct perf_event;
*/
#define PERF_EVENT_TXN 0x1
+#define PERF_PMU_TXN_ADD 0x1 /* txn to add/schedule event on PMU */
+
/**
* pmu::capabilities flags
*/
@@ -331,20 +333,26 @@ struct pmu {
*
* Start the transaction, after this ->add() doesn't need to
* do schedulability tests.
+ *
+ * Optional.
*/
- void (*start_txn) (struct pmu *pmu); /* optional */
+ void (*start_txn) (struct pmu *pmu, unsigned int txn_flags);
/*
* If ->start_txn() disabled the ->add() 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.
+ *
+ * Optional.
*/
- int (*commit_txn) (struct pmu *pmu); /* optional */
+ int (*commit_txn) (struct pmu *pmu);
/*
* Will cancel the transaction, assumes ->del() is called
* for each successful ->add() during the transaction.
+ *
+ * Optional.
*/
- void (*cancel_txn) (struct pmu *pmu); /* optional */
+ void (*cancel_txn) (struct pmu *pmu);
/*
* Will return the value for perf_event_mmap_page::index for this event,
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