mirror of
https://github.com/freebsd/freebsd-src
synced 2024-07-23 19:28:36 +00:00
20f8814cd3
Measure the total deferred time (from the time we decide to defer until we try again) for busdma_load requests. On systems that don't ever defer, there is no performnce change. Add new sysctl hw.busdma.zoneX.total_deferred_time to report this (in microseconds). Normally, deferrals don't happen in modern hardware... Except there's a lot of buggy hardware that can't cope with memory > 4GB or that can't cross a 4GB boundary (or even more restrictive values), necessitating bouncing. This will measure the effect on the I/Os of this deferral. Sponsored by: Netflix Reviewed by: gallatin, mav Differential Revision: https://reviews.freebsd.org/D42550 |
||
|---|---|---|
| .. | ||
| acpica | ||
| bios | ||
| conf | ||
| cpufreq | ||
| include | ||
| iommu | ||
| isa | ||
| linux | ||
| pci | ||
| x86 | ||
| xen | ||