Re: [PATCH v2 0/5] x86/mm/pat: CPA fixes
"Lorenzo Stoakes (ARM)" <[email protected]>
| Newsgroups | org.kernel.vger.stable,dev.linux.lists.iommu,org.kernel.vger.linux-kernel,org.kvack.linux-mm |
|---|---|
| Message-ID | <ao1EtJG_Gj8f90WQ@gremlin> |
On Tue, Aug 25, 2026 at 12:12:32AM -0700, Atish Patra wrote: > Reproduced and verified this series (patches 1-3) on 4vcpu guest running two different kernels > 1. mainline (commit: 77ae27fd98f3) > 2. Ubuntu Resolute 7.0.0-26 (production kernel hitting the issue in a VM) > > The Reproducer consisted of > 1. A debug patch a cmdline-gated stall between the two *pmd reads in vmalloc_to_page() > 2. One taskset-pinned insmod/rmmod worker per module over stock cfg80211/dummy/veth modules > > With the above reproducer, both BUG within seconds in unpatched kernel. > 1. Resolute in 0.71s at alternative.c:2564 (BUG_ON(!pages[0] ...), RAX=0) > 2. mainline at alternative.c:2473 (BUG_ON(memcmp(addr, src, len))). > > With patches 1-3: zero splats across 10 runs each (600s/11,378 module load/unload cycles on mainline and 1200s/55,980 module load/unload cycles on Resolute). Amazing, thanks! > > > Tested-by: Atish Patra<[email protected]> I guess should be applied to patches 1-3 only strictly? Or perhaps 3/5? > > > -- > > Sincerely yours, > > Mike. > > -- Cheers, Lorenzo