Messages in this thread | | | From | Tim Chen <> | Subject | Re: [RFC PATCH v4 00/19] Core scheduling v4 | Date | Wed, 5 Feb 2020 16:28:18 -0800 |
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On 1/14/20 7:40 AM, Vineeth Remanan Pillai wrote: > On Mon, Jan 13, 2020 at 8:12 PM Tim Chen <tim.c.chen@linux.intel.com> wrote: > >> I also encountered kernel panic with the v4 code when taking cpu offline or online >> when core scheduler is running. I've refreshed the previous patch, along >> with 3 other patches to fix problems related to CPU online/offline. >> >> As a side effect of the fix, each core can now operate in core-scheduling >> mode or non core-scheduling mode, depending on how many online SMT threads it has. >> >> Vineet, are you guys planning to refresh v4 and update it to v5? Aubrey posted >> a port to the latest kernel earlier. >> > Thanks for the updated patch Tim. > > We have been testing with v4 rebased on 5.4.8 as RC kernels had given us > trouble in the past. v5 is due soon and we are planning to release v5 when > 5.5 comes out. As of now, v5 has your crash fixes and Aubrey's changes > related to load balancing. We are investigating a performance issue with > high overcommit io intensive workload and also we are trying to see if > we can add synchronization during VMEXITs so that a guest vm cannot run > run alongside with host kernel. We also need to think about the userland > interface for corescheduling in preparation for upstreaming work. >
Vineet,
Have you guys been able to make progress on the issues with I/O intensive workload?
Can you explain a bit further what the problem is? Is the VM doing lots of I/O, causing frequent VMEXITs? And the the host thread doing the I/O cannot run along side with vcpu thread, resulting in extra forced idle? So you are trying not to put vcpu on the same core with such host thread?
Tim
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