On 25.06.19 10:01, David Hildenbrand wrote: > On 25.06.19 09:52, Oscar Salvador wrote: >> remove_memory_block_devices() checks for the range to be aligned >> to memory_block_size_bytes, which is our current memory block size, >> and WARNs_ON and bails out if it is not. >> >> This is the right to do, but we do already do that in try_remove_memory(), >> where remove_memory_block_devices() gets called from, and we even are >> more strict in try_remove_memory, since we directly BUG_ON in case the range >> is not properly aligned. >> >> Since remove_memory_block_devices() is only called from try_remove_memory(), >> we can safely drop the check here. >> >> To be honest, I am not sure if we should kill the system in case we cannot >> remove memory. >> I tend to think that WARN_ON and return and error is better. > > I failed to parse this sentence. > >> >> Signed-off-by: Oscar Salvador <osalvador@xxxxxxx> >> --- >> drivers/base/memory.c | 4 ---- >> 1 file changed, 4 deletions(-) >> >> diff --git a/drivers/base/memory.c b/drivers/base/memory.c >> index 826dd76f662e..07ba731beb42 100644 >> --- a/drivers/base/memory.c >> +++ b/drivers/base/memory.c >> @@ -771,10 +771,6 @@ void remove_memory_block_devices(unsigned long start, unsigned long size) >> struct memory_block *mem; >> int block_id; >> >> - if (WARN_ON_ONCE(!IS_ALIGNED(start, memory_block_size_bytes()) || >> - !IS_ALIGNED(size, memory_block_size_bytes()))) >> - return; >> - >> mutex_lock(&mem_sysfs_mutex); >> for (block_id = start_block_id; block_id != end_block_id; block_id++) { >> mem = find_memory_block_by_id(block_id, NULL); >> > > As I said when I introduced this, I prefer to have such duplicate checks > in place in case we have dependent code splattered over different files. > (especially mm/ vs. drivers/base). Such simple checks avoid to document > "start and size have to be aligned to memory blocks". Lol, I even documented it as well. So yeah, if you're going to drop this once, also drop the one in create_memory_block_devices(). > > If you still insist, then also remove the same sequence from > create_memory_block_devices(). > -- Thanks, David / dhildenb