| Message ID | 20210209133854.17399-6-osalvador@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Allocate memmap from hotadded memory (per device) | expand |
On 09.02.21 14:38, Oscar Salvador wrote: > Many places expects us to pass a pageblock aligned range. > E.g: memmap_init_zone() needs a pageblock aligned range in order > to set the proper migrate type for it. > online_pages() needs to operate on a pageblock aligned range for > isolation purposes. > > Make sure we disable the feature in case we cannot guarantee the > right alignment. > > Signed-off-by: Oscar Salvador <osalvador@suse.de> > --- > mm/memory_hotplug.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index d3fb036d33fd..1a4d5dd1a2c8 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -56,12 +56,16 @@ static int memmap_on_memory_show(char *buffer, const struct kernel_param *kp) > static __meminit int memmap_on_memory_store(const char *val, > const struct kernel_param *kp) > { > + unsigned long pageblock_size = PFN_PHYS(pageblock_nr_pages); > + > /* > * Fail silently in case we cannot enable it due to system constraints. > * User can always check whether it is enabled or not via /sys/module. > */ > if (!IS_ENABLED(CONFIG_ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE) || > - (PMD_SIZE % sizeof(struct page))) > + (PMD_SIZE % sizeof(struct page)) || > + !(MIN_MEMORY_BLOCK_SIZE - PMD_SIZE) || > + !(MIN_MEMORY_BLOCK_SIZE - PMD_SIZE) % pageblock_size) > return 0; > > return param_set_bool(val, kp); > Dito, rather squash in #1 and add a comment explaining what's happening there.
On Thu, Feb 25, 2021 at 07:27:33PM +0100, David Hildenbrand wrote: > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > > index d3fb036d33fd..1a4d5dd1a2c8 100644 > > --- a/mm/memory_hotplug.c > > +++ b/mm/memory_hotplug.c > > @@ -56,12 +56,16 @@ static int memmap_on_memory_show(char *buffer, const struct kernel_param *kp) > > static __meminit int memmap_on_memory_store(const char *val, > > const struct kernel_param *kp) > > { > > + unsigned long pageblock_size = PFN_PHYS(pageblock_nr_pages); > > + > > /* > > * Fail silently in case we cannot enable it due to system constraints. > > * User can always check whether it is enabled or not via /sys/module. > > */ > > if (!IS_ENABLED(CONFIG_ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE) || > > - (PMD_SIZE % sizeof(struct page))) > > + (PMD_SIZE % sizeof(struct page)) || > > + !(MIN_MEMORY_BLOCK_SIZE - PMD_SIZE) || > > + !(MIN_MEMORY_BLOCK_SIZE - PMD_SIZE) % pageblock_size) > > return 0; > > return param_set_bool(val, kp); > > > > Dito, rather squash in #1 and add a comment explaining what's happening > there. I was not sure about putting this and the PMD aligned patch as a standalone patch, but I thought it might ease the review. But I have no problem in placing them in patch#1 and put some more detail into the changelog.
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index d3fb036d33fd..1a4d5dd1a2c8 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -56,12 +56,16 @@ static int memmap_on_memory_show(char *buffer, const struct kernel_param *kp) static __meminit int memmap_on_memory_store(const char *val, const struct kernel_param *kp) { + unsigned long pageblock_size = PFN_PHYS(pageblock_nr_pages); + /* * Fail silently in case we cannot enable it due to system constraints. * User can always check whether it is enabled or not via /sys/module. */ if (!IS_ENABLED(CONFIG_ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE) || - (PMD_SIZE % sizeof(struct page))) + (PMD_SIZE % sizeof(struct page)) || + !(MIN_MEMORY_BLOCK_SIZE - PMD_SIZE) || + !(MIN_MEMORY_BLOCK_SIZE - PMD_SIZE) % pageblock_size) return 0; return param_set_bool(val, kp);
Many places expects us to pass a pageblock aligned range. E.g: memmap_init_zone() needs a pageblock aligned range in order to set the proper migrate type for it. online_pages() needs to operate on a pageblock aligned range for isolation purposes. Make sure we disable the feature in case we cannot guarantee the right alignment. Signed-off-by: Oscar Salvador <osalvador@suse.de> --- mm/memory_hotplug.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)