8d04284281
For interrupt coalescing, cv_timedwait_hires() uses a 100us slack/delta for calls to schedule_hrtimeout_range(). This 100us slack can be costly for small writes. This change improves small write performance by passing resolution `res` parameter to schedule_hrtimeout_range() to be used as delta/slack. A new tunable `spl_schedule_hrtimeout_slack_us` is added to preserve old behavior when desired. Performance observations on 8K recordsize filesystem: - 8K random writes at 1-64 threads, up to 60% improvement for one thread and smaller gains as thread count increases. At >64 threads, 2-5% decrease in performance was observed. - 8K sequential writes, similar 60% improvement for one thread and leveling out around 64 threads. At >64 threads, 5-10% decrease in performance was observed. - 128K sequential write sees 1-5 for the 128K. No observed regression at high thread count. Testing done on Ubuntu 18.04 with 4.15 kernel, 8vCPUs and SSD storage on VMware ESX. Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com> Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Matt Ahrens <mahrens@delphix.com> Signed-off-by: Tony Nguyen <tony.nguyen@delphix.com> Closes #9217
The Solaris Porting Layer, SPL, is a Linux kernel module which provides a compatibility layer used by the ZFS on Linux project.
Installation
The latest version of the SPL is maintained as part of this repository. Only when building ZFS version 0.7.x or earlier must an external SPL release be used. These releases can be found at:
- Version 0.7.x: https://github.com/zfsonlinux/spl/tree/spl-0.7-release
- Version 0.6.5.x: https://github.com/zfsonlinux/spl/tree/spl-0.6.5-release
Release
The SPL is released under a GPLv2 license.
For more details see the NOTICE and THIRDPARTYLICENSE files; UCRL-CODE-235197