Bug 221974
| Summary: | cam iosched: The iops limiter should enforce limits below the quanta value and should not discard 'unspent' ios | ||||||
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| Product: | Base System | Reporter: | Fabian Keil <fk> | ||||
| Component: | kern | Assignee: | Warner Losh <imp> | ||||
| Status: | Closed FIXED | ||||||
| Severity: | Affects Some People | CC: | emaste, imp | ||||
| Priority: | --- | Keywords: | patch | ||||
| Version: | CURRENT | Flags: | fk:
mfc-stable11?
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| Hardware: | Any | ||||||
| OS: | Any | ||||||
| Attachments: |
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A commit references this bug: Author: imp Date: Fri Sep 22 02:36:32 UTC 2017 New revision: 323893 URL: https://svnweb.freebsd.org/changeset/base/323893 Log: cam iosched: Enforce iop limits below the quanta value Previously the iops limiter would always allow at least quanta ios per second as cam_iosched_iops_tick() never set ios->l_value1 below 1. Submitted by: Fabian Keil <fk@fabiankeil.de> Obtained from: ElectroBSD PR: 221974 Changes: head/sys/cam/cam_iosched.c A commit references this bug: Author: imp Date: Fri Sep 22 02:36:36 UTC 2017 New revision: 323894 URL: https://svnweb.freebsd.org/changeset/base/323894 Log: cam iosched: Bettar account IOPS for smoother performance Prevent cam_iosched_iops_tick() from discarding 'unspent' ios unless it's a new accounting interval. Previously ios that weren't used between ticks were lost, as a result the iops limiter could enforce a limit below the configured maximum. Obtained from: ElectroBSD Submitted by: Fabian Keil PR: 221974 Changes: head/sys/cam/cam_iosched.c imp, MFC plans? ^Triage: Assign to committer resolving With bugmeister hat, I think any possible MFCs from 3 years ago are OBE. |
Created attachment 185971 [details] cam iosched: Enforce iop limits below the quanta value and preserve "unspent" ios Currently the iops limiter allows at least one iop per tick, as a result limits below the quanta value aren't enforced. ios that aren't used between ticks are lost, as a result the iops limiter can enforce a limit significantly below the configured maximum. The attached patch set fixes both issues. Obtained from: ElectroBSD