[LU-8492] ptlrpc: Correctly calculate hrp->hrp_nthrs

Duplicate — Sun, 30 Jan 2022 09:57:56 +0000

This ticket separates out patch http://review.whamcloud.com/#/c/19106/ from ~~LU-6285~~ was already resolved when the new issue was identified (as noted in ~~LU-6285~~)

It addresses the following:

There is still an issue which could cause the assert.

cpu_pattern can sepcify exactly 1 cpu in a partition:
"0[0]". That means CPT0 will have CPU 0. CPU 0 can have
hyperthreading enabled. This combination would result in

weight = cfs_cpu_ht_nsiblings(0);
hrp->hrp_nthrs = cfs_cpt_weight(ptlrpc_hr.hr_cpt_table, i);
hrp->hrp_nthrs /= weight;

evaluating to 0. Where

cfs_cpt_weight(ptlrpc_hr.hr_cpt_table, i) == 1
weight == 2

Therefore only divide out with weight if

hrp->hrp_nthrs >= weight

This will avoid the assert:

LASSERT(hrp->hrp_nthrs > 0);

Whamcloud Community JIRA

[LU-8492] ptlrpc: Correctly calculate hrp->hrp_nthrs