On Tue, 2 Aug 2022 19:55:02 +0200 (CEST)
Mark Kettenis <mark.kette...@xs4all.nl> wrote:
> > Date: Tue, 2 Aug 2022 11:56:59 -0500
> > From: Scott Cheloha <scottchel...@gmail.com>
> >
> > At what point do we consider the patch safe? Have you seen any hangs?
> >
> > Wanna run with it another week?
>
> Sorry. I'm not set up to run my powerpc64 machine for extended
> periods of time. But I'm fine with this going in if George can
> confirm that this diff builds.
Yes, it builds. ok gkoehler@
I have been running this version of the diff for a few hours, after
switching from the previous version (which had modified trap.c).
> > Index: include/cpu.h
> > ===================================================================
> > RCS file: /cvs/src/sys/arch/powerpc64/include/cpu.h,v
> > retrieving revision 1.31
> > diff -u -p -r1.31 cpu.h
> > --- include/cpu.h 6 Jul 2021 09:34:07 -0000 1.31
> > +++ include/cpu.h 25 Jul 2022 23:43:47 -0000
> > @@ -74,9 +74,9 @@ struct cpu_info {
> > uint64_t ci_lasttb;
> > uint64_t ci_nexttimerevent;
> > uint64_t ci_nextstatevent;
> > - int ci_statspending;
> >
> > volatile int ci_cpl;
> > + volatile int ci_dec_deferred;
> > uint32_t ci_ipending;
> > uint32_t ci_idepth;
> > #ifdef DIAGNOSTIC
> > Index: powerpc64/clock.c
> > ===================================================================
> > RCS file: /cvs/src/sys/arch/powerpc64/powerpc64/clock.c,v
> > retrieving revision 1.3
> > diff -u -p -r1.3 clock.c
> > --- powerpc64/clock.c 23 Feb 2021 04:44:31 -0000 1.3
> > +++ powerpc64/clock.c 25 Jul 2022 23:43:47 -0000
> > @@ -98,6 +98,17 @@ decr_intr(struct trapframe *frame)
> > int s;
> >
> > /*
> > + * If the clock interrupt is masked, postpone all work until
> > + * it is unmasked in splx(9).
> > + */
> > + if (ci->ci_cpl >= IPL_CLOCK) {
> > + ci->ci_dec_deferred = 1;
> > + mtdec(UINT32_MAX >> 1); /* clear DEC exception */
> > + return;
> > + }
> > + ci->ci_dec_deferred = 0;
> > +
> > + /*
> > * Based on the actual time delay since the last decrementer reload,
> > * we arrange for earlier interrupt next time.
> > */
> > @@ -130,30 +141,23 @@ decr_intr(struct trapframe *frame)
> > mtdec(nextevent - tb);
> > mtdec(nextevent - mftb());
> >
> > - if (ci->ci_cpl >= IPL_CLOCK) {
> > - ci->ci_statspending += nstats;
> > - } else {
> > - nstats += ci->ci_statspending;
> > - ci->ci_statspending = 0;
> > -
> > - s = splclock();
> > - intr_enable();
> > -
> > - /*
> > - * Do standard timer interrupt stuff.
> > - */
> > - while (ci->ci_lasttb < prevtb) {
> > - ci->ci_lasttb += tick_increment;
> > - clock_count.ec_count++;
> > - hardclock((struct clockframe *)frame);
> > - }
> > + s = splclock();
> > + intr_enable();
> >
> > - while (nstats-- > 0)
> > - statclock((struct clockframe *)frame);
> > -
> > - intr_disable();
> > - splx(s);
> > + /*
> > + * Do standard timer interrupt stuff.
> > + */
> > + while (ci->ci_lasttb < prevtb) {
> > + ci->ci_lasttb += tick_increment;
> > + clock_count.ec_count++;
> > + hardclock((struct clockframe *)frame);
> > }
> > +
> > + while (nstats-- > 0)
> > + statclock((struct clockframe *)frame);
> > +
> > + intr_disable();
> > + splx(s);
> > }
> >
> > void
> > Index: powerpc64/intr.c
> > ===================================================================
> > RCS file: /cvs/src/sys/arch/powerpc64/powerpc64/intr.c,v
> > retrieving revision 1.9
> > diff -u -p -r1.9 intr.c
> > --- powerpc64/intr.c 26 Sep 2020 17:56:54 -0000 1.9
> > +++ powerpc64/intr.c 25 Jul 2022 23:43:47 -0000
> > @@ -139,6 +139,11 @@ splx(int new)
> > {
> > struct cpu_info *ci = curcpu();
> >
> > + if (ci->ci_dec_deferred && new < IPL_CLOCK) {
> > + mtdec(0);
> > + mtdec(UINT32_MAX); /* raise DEC exception */
> > + }
> > +
> > if (ci->ci_ipending & intr_smask[new])
> > intr_do_pending(new);
> >
> >
