| Message ID | 20200703031828.14645-1-richard.weiyang@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] mm/sparse: only sub-section aligned range would be populated | expand |
On 03.07.20 05:18, Wei Yang wrote: > There are two code path which invoke __populate_section_memmap() > > * sparse_init_nid() > * sparse_add_section() > > For both case, we are sure the memory range is sub-section aligned. > > * we pass PAGES_PER_SECTION to sparse_init_nid() > * we check range by check_pfn_span() before calling > sparse_add_section() > > Also, the counterpart of __populate_section_memmap(), we don't do such > calculation and check since the range is checked by check_pfn_span() in > __remove_pages(). > > Clear the calculation and check to keep it simple and comply with its > counterpart. > > Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> > > --- > v2: > * add a warn on once for unaligned range, suggested by David > --- > mm/sparse-vmemmap.c | 20 ++++++-------------- > 1 file changed, 6 insertions(+), 14 deletions(-) > > diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c > index 0db7738d76e9..8d3a1b6287c5 100644 > --- a/mm/sparse-vmemmap.c > +++ b/mm/sparse-vmemmap.c > @@ -247,20 +247,12 @@ int __meminit vmemmap_populate_basepages(unsigned long start, > struct page * __meminit __populate_section_memmap(unsigned long pfn, > unsigned long nr_pages, int nid, struct vmem_altmap *altmap) > { > - unsigned long start; > - unsigned long end; > - > - /* > - * The minimum granularity of memmap extensions is > - * PAGES_PER_SUBSECTION as allocations are tracked in the > - * 'subsection_map' bitmap of the section. > - */ > - end = ALIGN(pfn + nr_pages, PAGES_PER_SUBSECTION); > - pfn &= PAGE_SUBSECTION_MASK; > - nr_pages = end - pfn; > - > - start = (unsigned long) pfn_to_page(pfn); > - end = start + nr_pages * sizeof(struct page); > + unsigned long start = (unsigned long) pfn_to_page(pfn); > + unsigned long end = start + nr_pages * sizeof(struct page); > + > + if (WARN_ON_ONCE(!IS_ALIGNED(pfn, PAGES_PER_SUBSECTION) || > + !IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION))) > + return NULL; Nit: indentation of both IS_ALIGNED should match. Acked-by: David Hildenbrand <david@redhat.com> > > if (vmemmap_populate(start, end, nid, altmap)) > return NULL; >
On Fri, Jul 03, 2020 at 11:18:28AM +0800, Wei Yang wrote: >There are two code path which invoke __populate_section_memmap() > > * sparse_init_nid() > * sparse_add_section() > >For both case, we are sure the memory range is sub-section aligned. > > * we pass PAGES_PER_SECTION to sparse_init_nid() > * we check range by check_pfn_span() before calling > sparse_add_section() > >Also, the counterpart of __populate_section_memmap(), we don't do such >calculation and check since the range is checked by check_pfn_span() in >__remove_pages(). > >Clear the calculation and check to keep it simple and comply with its >counterpart. > >Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> > Hi, Andrew, Is this one picked up? >--- >v2: > * add a warn on once for unaligned range, suggested by David >--- > mm/sparse-vmemmap.c | 20 ++++++-------------- > 1 file changed, 6 insertions(+), 14 deletions(-) > >diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c >index 0db7738d76e9..8d3a1b6287c5 100644 >--- a/mm/sparse-vmemmap.c >+++ b/mm/sparse-vmemmap.c >@@ -247,20 +247,12 @@ int __meminit vmemmap_populate_basepages(unsigned long start, > struct page * __meminit __populate_section_memmap(unsigned long pfn, > unsigned long nr_pages, int nid, struct vmem_altmap *altmap) > { >- unsigned long start; >- unsigned long end; >- >- /* >- * The minimum granularity of memmap extensions is >- * PAGES_PER_SUBSECTION as allocations are tracked in the >- * 'subsection_map' bitmap of the section. >- */ >- end = ALIGN(pfn + nr_pages, PAGES_PER_SUBSECTION); >- pfn &= PAGE_SUBSECTION_MASK; >- nr_pages = end - pfn; >- >- start = (unsigned long) pfn_to_page(pfn); >- end = start + nr_pages * sizeof(struct page); >+ unsigned long start = (unsigned long) pfn_to_page(pfn); >+ unsigned long end = start + nr_pages * sizeof(struct page); >+ >+ if (WARN_ON_ONCE(!IS_ALIGNED(pfn, PAGES_PER_SUBSECTION) || >+ !IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION))) >+ return NULL; > > if (vmemmap_populate(start, end, nid, altmap)) > return NULL; >-- >2.20.1 (Apple Git-117)
On 05.08.20 23:49, Wei Yang wrote: > On Fri, Jul 03, 2020 at 11:18:28AM +0800, Wei Yang wrote: >> There are two code path which invoke __populate_section_memmap() >> >> * sparse_init_nid() >> * sparse_add_section() >> >> For both case, we are sure the memory range is sub-section aligned. >> >> * we pass PAGES_PER_SECTION to sparse_init_nid() >> * we check range by check_pfn_span() before calling >> sparse_add_section() >> >> Also, the counterpart of __populate_section_memmap(), we don't do such >> calculation and check since the range is checked by check_pfn_span() in >> __remove_pages(). >> >> Clear the calculation and check to keep it simple and comply with its >> counterpart. >> >> Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> >> > > Hi, Andrew, > > Is this one picked up? I can spot it in -next via the -mm tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=68ad9becb23be14622e39ed36e5b0621a90a41d9
On Thu, Aug 06, 2020 at 09:29:36AM +0200, David Hildenbrand wrote: >On 05.08.20 23:49, Wei Yang wrote: >> On Fri, Jul 03, 2020 at 11:18:28AM +0800, Wei Yang wrote: >>> There are two code path which invoke __populate_section_memmap() >>> >>> * sparse_init_nid() >>> * sparse_add_section() >>> >>> For both case, we are sure the memory range is sub-section aligned. >>> >>> * we pass PAGES_PER_SECTION to sparse_init_nid() >>> * we check range by check_pfn_span() before calling >>> sparse_add_section() >>> >>> Also, the counterpart of __populate_section_memmap(), we don't do such >>> calculation and check since the range is checked by check_pfn_span() in >>> __remove_pages(). >>> >>> Clear the calculation and check to keep it simple and comply with its >>> counterpart. >>> >>> Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> >>> >> >> Hi, Andrew, >> >> Is this one picked up? > >I can spot it in -next via the -mm tree: > >https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=68ad9becb23be14622e39ed36e5b0621a90a41d9 > Thanks ;-) Next time I would refer to this repo first. > >-- >Thanks, > >David / dhildenb
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 0db7738d76e9..8d3a1b6287c5 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -247,20 +247,12 @@ int __meminit vmemmap_populate_basepages(unsigned long start, struct page * __meminit __populate_section_memmap(unsigned long pfn, unsigned long nr_pages, int nid, struct vmem_altmap *altmap) { - unsigned long start; - unsigned long end; - - /* - * The minimum granularity of memmap extensions is - * PAGES_PER_SUBSECTION as allocations are tracked in the - * 'subsection_map' bitmap of the section. - */ - end = ALIGN(pfn + nr_pages, PAGES_PER_SUBSECTION); - pfn &= PAGE_SUBSECTION_MASK; - nr_pages = end - pfn; - - start = (unsigned long) pfn_to_page(pfn); - end = start + nr_pages * sizeof(struct page); + unsigned long start = (unsigned long) pfn_to_page(pfn); + unsigned long end = start + nr_pages * sizeof(struct page); + + if (WARN_ON_ONCE(!IS_ALIGNED(pfn, PAGES_PER_SUBSECTION) || + !IS_ALIGNED(nr_pages, PAGES_PER_SUBSECTION))) + return NULL; if (vmemmap_populate(start, end, nid, altmap)) return NULL;
There are two code path which invoke __populate_section_memmap() * sparse_init_nid() * sparse_add_section() For both case, we are sure the memory range is sub-section aligned. * we pass PAGES_PER_SECTION to sparse_init_nid() * we check range by check_pfn_span() before calling sparse_add_section() Also, the counterpart of __populate_section_memmap(), we don't do such calculation and check since the range is checked by check_pfn_span() in __remove_pages(). Clear the calculation and check to keep it simple and comply with its counterpart. Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com> --- v2: * add a warn on once for unaligned range, suggested by David --- mm/sparse-vmemmap.c | 20 ++++++-------------- 1 file changed, 6 insertions(+), 14 deletions(-)