On Thu, Mar 26, 2020 at 2:47 PM Waiman Long <longman@xxxxxxxxxx> wrote: > > On 3/26/20 4:05 PM, Sonny Rao wrote: > >> I think Tejun is concerned about a change in the default behavior of > >> cpuset v1. > >> > >> There is a special v2 mode for cpuset that is enabled by the mount > >> option "cpuset_v2_mode". This causes the cpuset v1 to adopt some of the > >> v2 behavior. I introduced this v2 mode a while back to address, I think, > >> a similar concern. Could you try that to see if it is able to address > >> your problem? If not, you can make some code adjustment within the > >> framework of the v2 mode. As long as it is an opt-in, I think we are > >> open to further change. > > I am surprised if anyone actually wants this behavior, we (Chrome OS) > > found out about it accidentally, and then found that Android had been > > carrying a patch to fix it. And if it were a desirable behavior then > > why isn't it an option in v2? > > > I am a bit confused. The v2 mode make cpuset v1 behaves more like cpuset > v2. The original v1 behavior has some obvious issue that was fixed in > v2. So what v2 option are you talking about? I was merely pointing out the behavior of the v1 implementation is so undesirable that it wasn't kept at all in v2. IMHO, it's a bug that should be fixed, and I think it's possible to keep the old behavior if all cpus are offlined, but since you've added this option we can use it instead. > > Regards, > Longman >
