Henry Robinson has posted comments on this change. Change subject: IMPALA-4456: Change query_exec_state_lock_ to a reader-writer lock ......................................................................
Patch Set 2: (4 comments) http://gerrit.cloudera.org:8080/#/c/5021/2//COMMIT_MSG Commit Message: PS2, Line 11: to with PS2, Line 13: This can reduce the amount of lock contention on this and translates : to big wins both in terms of performance and scalability. : : Please refer the JIRA for more information. Quantify what "big win" means. http://gerrit.cloudera.org:8080/#/c/5021/2/be/src/service/impala-server.h File be/src/service/impala-server.h: Line 673: /// acquisition order. Update comment with expected read and write usage, and also update class comment if locking order is different for reader and writer locks. http://gerrit.cloudera.org:8080/#/c/5021/2/be/src/util/rw_lock.h File be/src/util/rw_lock.h: PS2, Line 25: class ReadWriteLock { : public: : ReadWriteLock() {} : : // Reader lock functions. : void ReadAcquire() { l.ReadAcquire(); } : void ReadRelease() { l.ReadRelease(); } : : // Writer lock functions. : void WriteAcquire() { l.WriteAcquire(); } : void WriteRelease() { l.WriteRelease(); } : : private: : base::subtle::ReadWriteLock l; : : DISALLOW_COPY_AND_ASSIGN(ReadWriteLock); : }; Why does this class need to exist? -- To view, visit http://gerrit.cloudera.org:8080/5021 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-MessageType: comment Gerrit-Change-Id: I790a95e7179f07aa7ba188d5422c5e054353ba0b Gerrit-PatchSet: 2 Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-Owner: Sailesh Mukil <sail...@cloudera.com> Gerrit-Reviewer: Henry Robinson <he...@cloudera.com> Gerrit-HasComments: Yes
