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Bug #20385

closed

jemalloc+Bluestore+BlueFS causes unexpected RSS Memory usage growth

Added by Igor Fedotov almost 7 years ago. Updated about 6 years ago.

Status:
Won't Fix
Priority:
Low
Assignee:
-
Target version:
-
% Done:

0%

Source:
Tags:
Backport:
Regression:
No
Severity:
3 - minor
Reviewed:
Affected Versions:
ceph-qa-suite:
Pull request ID:
Crash signature (v1):
Crash signature (v2):

Description

When testing standalone BlueStore FIO plugin one can observe excessive RSS memory usage for corresponding FIO process. This occurs in case of write scenarios and BlueFS use only. Regular OSD probably suffers from the same issue as well.
The root cause is the lack for BlueFS::_flush_bdev_safely() call for one of BlueFS files that probably results in memory fragmentation and prevents from returning unused pages to OS. I suppose the file in question is log_writer one. In fact that's rather lack of BlueFS::flush_log() call that's absent over the code.

One can insert corresponding function call (_flush_bdev_safely()) at the end of BlueFS::_flush_range as a workaround and/or root cause's proof.

Files

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aLL4.fio (456 Bytes) aLL4.fio fio job to precondition the store Igor Fedotov, 06/30/2017 03:07 PM
ceph-5.conf (4.15 KB) ceph-5.conf config file for overwrite scenario Igor Fedotov, 06/30/2017 03:07 PM
ceph-bluestore-somnath.conf (3.43 KB) ceph-bluestore-somnath.conf config for precondition Igor Fedotov, 06/30/2017 03:07 PM
w4-5.fio (391 Bytes) w4-5.fio fio job to execute overwrite benchmark Igor Fedotov, 06/30/2017 03:07 PM
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