On Sun, 1 Aug 2021, Stan Johnson wrote: > > > >> Could you try without CONFIG_VMAP_STACK > >> > > > > Stan, would you please test the following build: > > > > $ git checkout v5.13 > > $ cp ../dot-config-powermac-5.13 .config > > $ scripts/config -d CONFIG_VMAP_STACK > > $ make ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu- -j4 clean olddefconfig > > vmlinux > > > Please see the attached serial console log (four boots): > 1) v5.13-mac, CONFIG_VMAP_STACK=y, mem=512M (fails) > 2) v5.13-mac, CONFIG_VMAP_STACK=y, mem=384M (works) > 3) v5.13-mac, CONFIG_VMAP_STACK=n, mem=512M (works) > 4) v5.13-mac, CONFIG_VMAP_STACK=n, mem=384M (works) > > My apologies if the extra boots were not needed (due to the time > difference, I'm trying to anticipate future requests). > > Cutting and pasting Finn's commands above builds a new kernel > (5.13.0-pmac) with the following in .config: > > $ fgrep VMAP .config > CONFIG_HAVE_ARCH_VMAP_STACK=y > CONFIG_VMAP_STACK=y >
That's odd. It works correctly here: $ cp ../dot-config-powermac-5.13 .config $ grep CONFIG_VMAP_STACK .config CONFIG_VMAP_STACK=y $ scripts/config -d CONFIG_VMAP_STACK $ grep CONFIG_VMAP_STACK .config # CONFIG_VMAP_STACK is not set Anyway, I see that you resolved the problem: > ... > > $ fgrep VMAP .config > CONFIG_HAVE_ARCH_VMAP_STACK=y > # CONFIG_VMAP_STACK is not set > > 3) Same as 1 (512M) but with CONFIG_VMAP_STACK not set in v5.13. > Everything works (no problems with X, no errors logged). > > 4) Same as 2 (384M) but with CONFIG_VMAP_STACK not set in v5.13. > Everything works (no problems with X, no errors logged). > Thanks for collecting those results. It appears that Christophe was right. Disabling CONFIG_VMAP_STACK avoids the crashes in v5.13. (Enabling CONFIG_VMAP_STACK worked fine in v5.12.)
