On Sat, Oct 12, 2013 at 05:58:51PM -0400, Santosh Shilimkar wrote: > From: Grygorii Strashko <grygorii.strashko@xxxxxx> > > Now the Nobootmem allocator will always try to free memory allocated for > reserved memory regions (free_low_memory_core_early()) without taking > into to account current memblock debugging configuration > (CONFIG_ARCH_DISCARD_MEMBLOCK and CONFIG_DEBUG_FS state). > As result if: > - CONFIG_DEBUG_FS defined > - CONFIG_ARCH_DISCARD_MEMBLOCK not defined; > - reserved memory regions array have been resized during boot > > then: > - memory allocated for reserved memory regions array will be freed to > buddy allocator; > - debug_fs entry "sys/kernel/debug/memblock/reserved" will show garbage > instead of state of memory reservations. like: > 0: 0x98393bc0..0x9a393bbf > 1: 0xff120000..0xff11ffff > 2: 0x00000000..0xffffffff > > Hence, do not free memory allocated for reserved memory regions if > defined(CONFIG_DEBUG_FS) && !defined(CONFIG_ARCH_DISCARD_MEMBLOCK). > > Cc: Yinghai Lu <yinghai@xxxxxxxxxx> > Cc: Tejun Heo <tj@xxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > > Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx> > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> > --- > mm/memblock.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/mm/memblock.c b/mm/memblock.c > index d903138..1bb2cc0 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -169,6 +169,10 @@ phys_addr_t __init_memblock get_allocated_memblock_reserved_regions_info( > if (memblock.reserved.regions == memblock_reserved_init_regions) > return 0; > Please add comment explaining why the following test exists. It's pretty difficult to deduce the reason only from the code. > + if (IS_ENABLED(CONFIG_DEBUG_FS) && > + !IS_ENABLED(CONFIG_ARCH_DISCARD_MEMBLOCK)) > + return 0; > + Also, as this is another fix patch, can you please move this to the head of the series? Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>