Helge Deller <deller@xxxxxx> writes: > * Sven Schnelle <svens@xxxxxxxxxxxxxx>: >> John David Anglin <dave.anglin@xxxxxxxx> writes: >> >> > On 2021-10-17 12:30 p.m., Helge Deller wrote: >> >> It seems the warnings are gone if I remove the irq masking. >> >> I see the options: >> >> a) revert the irq masking in syscall.S. Not sure if it really hurts performance. >> >> b) revert the patch from Sven. >> >> c) insert code to turn back irq on in the fault handler if we are on the gateway page. >> >> What is your thought? >> > >> > After some thought, I believe option a) is the best. I no longer think interrupts can be >> > disabled in the futex and cmpxchg operations because of COW breaks. This not ideal but >> > I suspect it's the best we can do. >> > >> > For the cmpxchg operations in syscall.S, we rely on the code to not schedule off the gateway >> > page. For the futex, I added code to disable preemption. >> > >> > So far, I haven't seen the warnings with the attached change but the change is only lightly tested. >> >> Thanks Dave. I just applied it to my tree and will give it a spin. > > Sven, did you had some outcome? The outcome is that i haven't seen any problems yet. > I've cleaned up Daves patch and applied it to my for-next tree: > https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git/commit/?h=for-next&id=b7cd8a368c986abf184e609772b083f43e5d522d > together with this patch from Sven ("parisc: don't enable irqs > unconditionally in handle_interruption()"): > https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git/commit/?h=for-next&id=493f84fcb3a791350ffaa2fa2984a0815a924e39 > > When not applying to master branch from Linus, this patch is needed as well: > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1030d681319b43869e0d5b568b9d0226652d1a6f > > All is in my for-next tree. > Testing seems that those are OK and I don't see any > "BUG: using __this_cpu_add() in preemptible [00000000] code" warnings > any more. > > Any objections if I push those patches to Linus soon? No objections. Sven
