[Impala-CR](cdh5-2.5.0_5.7.0) IMPALA-3142: avoid spinlock in MemTracker::GcMemory()

["Tim Armstrong (Code Review)" <ge...@cloudera.org>]

Tim Armstrong has uploaded a new change for review.

  http://gerrit.cloudera.org:8080/2459

Change subject: IMPALA-3142: avoid spinlock in MemTracker::GcMemory()
......................................................................

IMPALA-3142: avoid spinlock in MemTracker::GcMemory()

When the process memory limit is exceeded we see excessive contention
for the gc_lock_ in the process memory tracker. A SpinLock is not a good
fit for this lock because we expect high contention (when the process
memory limit is exceeded, it is exceeded globally and many threads will
try to call into the function at the same time). boost::mutex will fall
back to a kernel-level mutex and block the process instead of spinning.

Change-Id: Ia9e91ea67ea924ba9b81e7376487838b365ca8ce
---
M be/src/runtime/mem-tracker.cc
M be/src/runtime/mem-tracker.h
2 files changed, 2 insertions(+), 2 deletions(-)


  git pull ssh://gerrit.cloudera.org:29418/Impala refs/changes/59/2459/1
-- 
To view, visit http://gerrit.cloudera.org:8080/2459
To unsubscribe, visit http://gerrit.cloudera.org:8080/settings

Gerrit-MessageType: newchange
Gerrit-Change-Id: Ia9e91ea67ea924ba9b81e7376487838b365ca8ce
Gerrit-PatchSet: 1
Gerrit-Project: Impala
Gerrit-Branch: cdh5-2.5.0_5.7.0
Gerrit-Owner: Tim Armstrong <ta...@cloudera.com>