applied to acpi test tree. thanks, -len On Tuesday 11 March 2008, Rafael J. Wysocki wrote: > Hi Len, > > The following patch fixes http://bugzilla.kernel.org/show_bug.cgi?id=9966 . > > Although the problem has been there for quite some time (since before 2.6.22, > apparently), it would be good to have in 2.6.25, because it may fix booting > problems on the affected systems. > > Please note that it doesn't modify the code behavior on the systems which are > not affected by bug #9966 . > > Thanks, > Rafael > > > --- > From: Rafael J. Wysocki <rjw@xxxxxxx> > > There is a problem in the hibernation code that triggers on some NUMA > systems on which pfn_valid() returns 'true' for some PFNs that don't > belong to any zone. Namely, there is a BUG_ON() in > memory_bm_find_bit() that triggers for PFNs not belonging to any > zone and passing the pfn_valid() test. On the affected systems it > triggers when we mark PFNs reported by the platform as not saveable, > because the PFNs in question belong to a region mapped directly using > iorepam() (i.e. the ACPI data area) and they pass the pfn_valid() > test. > > Modify memory_bm_find_bit() so that it returns an error if given PFN > doesn't belong to any zone instead of crashing the kernel and ignore > the result returned by it in mark_nosave_pages(), while marking the > "nosave" memory regions. > > This doesn't affect the hibernation functionality, as we won't touch > the PFNs in question anyway. > > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> > --- > kernel/power/snapshot.c | 41 ++++++++++++++++++++++++++++++++++------- > 1 file changed, 34 insertions(+), 7 deletions(-) > > Index: linux-2.6/kernel/power/snapshot.c > =================================================================== > --- linux-2.6.orig/kernel/power/snapshot.c > +++ linux-2.6/kernel/power/snapshot.c > @@ -447,7 +447,7 @@ static void memory_bm_free(struct memory > * of @bm->cur_zone_bm are updated. > */ > > -static void memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, > +static int memory_bm_find_bit(struct memory_bitmap *bm, unsigned long pfn, > void **addr, unsigned int *bit_nr) > { > struct zone_bitmap *zone_bm; > @@ -461,7 +461,8 @@ static void memory_bm_find_bit(struct me > while (pfn < zone_bm->start_pfn || pfn >= zone_bm->end_pfn) { > zone_bm = zone_bm->next; > > - BUG_ON(!zone_bm); > + if (!zone_bm) > + return -EFAULT; > } > bm->cur.zone_bm = zone_bm; > } > @@ -479,23 +480,40 @@ static void memory_bm_find_bit(struct me > pfn -= bb->start_pfn; > *bit_nr = pfn % BM_BITS_PER_CHUNK; > *addr = bb->data + pfn / BM_BITS_PER_CHUNK; > + return 0; > } > > static void memory_bm_set_bit(struct memory_bitmap *bm, unsigned long pfn) > { > void *addr; > unsigned int bit; > + int error; > > - memory_bm_find_bit(bm, pfn, &addr, &bit); > + error = memory_bm_find_bit(bm, pfn, &addr, &bit); > + BUG_ON(error); > set_bit(bit, addr); > } > > +static int mem_bm_set_bit_check(struct memory_bitmap *bm, unsigned long pfn) > +{ > + void *addr; > + unsigned int bit; > + int error; > + > + error = memory_bm_find_bit(bm, pfn, &addr, &bit); > + if (!error) > + set_bit(bit, addr); > + return error; > +} > + > static void memory_bm_clear_bit(struct memory_bitmap *bm, unsigned long pfn) > { > void *addr; > unsigned int bit; > + int error; > > - memory_bm_find_bit(bm, pfn, &addr, &bit); > + error = memory_bm_find_bit(bm, pfn, &addr, &bit); > + BUG_ON(error); > clear_bit(bit, addr); > } > > @@ -503,8 +521,10 @@ static int memory_bm_test_bit(struct mem > { > void *addr; > unsigned int bit; > + int error; > > - memory_bm_find_bit(bm, pfn, &addr, &bit); > + error = memory_bm_find_bit(bm, pfn, &addr, &bit); > + BUG_ON(error); > return test_bit(bit, addr); > } > > @@ -709,8 +729,15 @@ static void mark_nosave_pages(struct mem > region->end_pfn << PAGE_SHIFT); > > for (pfn = region->start_pfn; pfn < region->end_pfn; pfn++) > - if (pfn_valid(pfn)) > - memory_bm_set_bit(bm, pfn); > + if (pfn_valid(pfn)) { > + /* > + * It is safe to ignore the result of > + * mem_bm_set_bit_check() here, since we won't > + * touch the PFNs for which the error is > + * returned anyway. > + */ > + mem_bm_set_bit_check(bm, pfn); > + } > } > } > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
