On Thu, 31 Jul 2014 14:58:58 +0530 Chintan Pandya <cpandya@xxxxxxxxxxxxxx> wrote: > > > > I think Andrew's comment earlier was referring to the changelog only and > > not the patch, which looked correct. > > I think Andrew asked for a BUG case details also to justify the > overhead. But we have never encountered that BUG case. Present patch is > only logical fix to the code. However, in the fast path, if such > overhead is allowed, I can move BUG_ON out of any debug configs. > Otherwise, as per Andrew's suggestion, I will convert DEBUG_HIGHMEM into > DEBUG_VM which is used more frequently. The v1 patch added a small amount of overhead to kmap_atomic() for what is evidently a very small benefit. Yes, I suggest we remove CONFIG_DEBUG_HIGHMEM from the kernel entirely and switch all CONFIG_DEBUG_HIGHMEM sites to use CONFIG_DEBUG_VM. That way the BUG_ON which you believe is useful will be tested by more people more often. -- 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>