Alpha kernel has been exhibiting rare and random memory corruptions/segaults in user space since the 5.9.y kernel. First seen on the Debian Ports build daemon when running 5.10.y kernel resulting in the occasional (one or two a day) build failures with gcc ICEs either due to self detected corrupt memory structures or segfaults. Have been running 5.8.y kernel without such problems for over six months. Tried bisecting last year but went off track with incorrect good/bad determinations due to rare nature of bug. After trying a 5.16.y kernel early this year and seen the bug is still present retried the bisection and have got to: aae466b0052e1888edd1d7f473d4310d64936196 is the first bad commit commit aae466b0052e1888edd1d7f473d4310d64936196 Author: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Date: Tue Aug 11 18:30:50 2020 -0700 mm/swap: implement workingset detection for anonymous LRU Pretty confident this is the bad commit as the kernel built to the parent commit (3852f6768ede54...) has not failed in four days running. Always have seen the failure within one day of running in past. Cheers, Michael.