[LU-3859] grant shrinker floods OST and produce a large load

• Type: Bug
• Resolution: Cannot Reproduce
• Priority: Critical
• Environment: xyratex lustre (mostly 2.1 based)
• Severity: 3
• Assignee: WC Triage
• Reporter: Alexey Lyashkov

Description

While invested a sort of LNet bugs i tried to dump a rpc cache on OST after fail and find most of rpc in cache is grant shrink requests - it's produce a large load to the routers and OST's.

ffff8807b9cc3440 rpc_cache               1024        313       896    224     4k
# grep -c RQF_OST_SET_GRANT_INFO \&\ log 
304

so 304 from 313 RPC's is flood from grant shrinker.

Issue Links

• is related to: LU-6951 sanity test_27m: @@@@@@ FAIL: OST0 was full but new created file still use it
• is related to: LU-8708 Grant shrinking disabled all the time
• is related to: LU-7015 Grant space and reserved blocks percent parameters