Re: I915 CI-run with kfence enabled, issues found

2021-03-29 Thread Andy Lutomirski
> On Mar 29, 2021, at 2:55 PM, Marco Elver wrote: > > On Mon, 29 Mar 2021 at 23:47, Andy Lutomirski wrote: >> >> On Mar 29, 2021, at 2:34 PM, Marco Elver wrote: >>> >>> On Mon, 29 Mar 2021 at 23:03, Dave Hansen wrote: > On 3/29/21 10:45 AM, Marco Elver wrote: >> On Mon, 29

Re: I915 CI-run with kfence enabled, issues found

2021-03-29 Thread Marco Elver
On Mon, 29 Mar 2021 at 23:47, Andy Lutomirski wrote: > > > > On Mar 29, 2021, at 2:34 PM, Marco Elver wrote: > > > > On Mon, 29 Mar 2021 at 23:03, Dave Hansen wrote: > >>> On 3/29/21 10:45 AM, Marco Elver wrote: > On Mon, 29 Mar 2021 at 19:32, Dave Hansen wrote: > >>> Doing it to all

Re: I915 CI-run with kfence enabled, issues found

2021-03-29 Thread Andy Lutomirski
> On Mar 29, 2021, at 2:34 PM, Marco Elver wrote: > > On Mon, 29 Mar 2021 at 23:03, Dave Hansen wrote: >>> On 3/29/21 10:45 AM, Marco Elver wrote: On Mon, 29 Mar 2021 at 19:32, Dave Hansen wrote: >>> Doing it to all CPUs is too expensive, and we can tolerate this being >>> approximate

Re: I915 CI-run with kfence enabled, issues found

2021-03-29 Thread Marco Elver
On Mon, 29 Mar 2021 at 23:03, Dave Hansen wrote: > On 3/29/21 10:45 AM, Marco Elver wrote: > > On Mon, 29 Mar 2021 at 19:32, Dave Hansen wrote: > > Doing it to all CPUs is too expensive, and we can tolerate this being > > approximate (nothing bad will happen, KFENCE might just miss a bug and > >

Re: I915 CI-run with kfence enabled, issues found

2021-03-29 Thread Dave Hansen
On 3/29/21 10:45 AM, Marco Elver wrote: > On Mon, 29 Mar 2021 at 19:32, Dave Hansen wrote: > Doing it to all CPUs is too expensive, and we can tolerate this being > approximate (nothing bad will happen, KFENCE might just miss a bug and > that's ok). ... >> BTW, the preempt checks in

Re: I915 CI-run with kfence enabled, issues found

2021-03-29 Thread Marco Elver
On Mon, 29 Mar 2021 at 19:32, Dave Hansen wrote: > > On 3/29/21 9:40 AM, Marco Elver wrote: > > It looks like the code path from flush_tlb_one_kernel() to > > invalidate_user_asid()'s this_cpu_ptr() has several feature checks, so > > probably some feature difference between systems where it

Re: I915 CI-run with kfence enabled, issues found

2021-03-29 Thread Dave Hansen
On 3/29/21 9:40 AM, Marco Elver wrote: > It looks like the code path from flush_tlb_one_kernel() to > invalidate_user_asid()'s this_cpu_ptr() has several feature checks, so > probably some feature difference between systems where it triggers and > it doesn't. > > As far as I'm aware, there is no

Re: I915 CI-run with kfence enabled, issues found

2021-03-29 Thread Marco Elver
[+Cc x86 maintainers] On Mon, Mar 29, 2021 at 11:11AM +, Sarvela, Tomi P wrote: > Hello, > > I'm Tomi Sarvela, maintainer and original creator of linux i915-CI: > https://intel-gfx-ci.01.org/ > > I got a hint from Martin Peres about kfence functionality in kernel, and it > looked >