| Message ID | 20230315113133.11326-7-kirill.shutemov@linux.intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Fix confusion around MAX_ORDER | expand |
On 3/15/23 12:31, Kirill A. Shutemov wrote: > MAX_ORDER is not inclusive: the maximum allocation order buddy allocator > can deliver is MAX_ORDER-1. > > Fix MAX_ORDER usage in rb_alloc_aux_page(). > > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Arnaldo Carvalho de Melo <acme@kernel.org> > Cc: Mark Rutland <mark.rutland@arm.com> > Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> > Cc: Jiri Olsa <jolsa@kernel.org> > Cc: Namhyung Kim <namhyung@kernel.org> > Cc: Ian Rogers <irogers@google.com> > Cc: Adrian Hunter <adrian.hunter@intel.com> > --- > kernel/events/ring_buffer.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c > index 273a0fe7910a..d6bbdb7830b2 100644 > --- a/kernel/events/ring_buffer.c > +++ b/kernel/events/ring_buffer.c > @@ -609,8 +609,8 @@ static struct page *rb_alloc_aux_page(int node, int order) > { > struct page *page; > > - if (order > MAX_ORDER) > - order = MAX_ORDER; > + if (order >= MAX_ORDER) > + order = MAX_ORDER - 1; > > do { > page = alloc_pages_node(node, PERF_AUX_GFP, order);
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c index 273a0fe7910a..d6bbdb7830b2 100644 --- a/kernel/events/ring_buffer.c +++ b/kernel/events/ring_buffer.c @@ -609,8 +609,8 @@ static struct page *rb_alloc_aux_page(int node, int order) { struct page *page; - if (order > MAX_ORDER) - order = MAX_ORDER; + if (order >= MAX_ORDER) + order = MAX_ORDER - 1; do { page = alloc_pages_node(node, PERF_AUX_GFP, order);
MAX_ORDER is not inclusive: the maximum allocation order buddy allocator can deliver is MAX_ORDER-1. Fix MAX_ORDER usage in rb_alloc_aux_page(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> --- kernel/events/ring_buffer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)