Re: [PATCH 5.15.y 0/2] fix softlockups in stage2_apply_range()

On Tue, Mar 05, 2024 at 11:41:38AM -0800, Krister Johansen wrote:

Hi Stable Team, In 5.15, unmapping large kvm vms on arm64 can generate softlockups. My team has been hitting this when tearing down VMs > 100Gb in size.

Oliver fixed this with the attached patches. They've been in mainline since 6.1.

I tested on 5.15.150 with these patches applied. When they're present, both the dirty_log_perf_test detailed in the second patch, and kvm_page_table_test no longer generate softlockups when unmapping VMs with large memory configurations.

Would you please consider these patches for inclusion in an upcoming 5.15 release?

Backport looks fine, and I have no issues with this going to stable if it helps folks.

Acked-by: Oliver Upton oliver.upton@linux.dev