Hello, On Fri, Sep 30, 2016 at 01:38:35AM +0800, zijun_hu wrote: > 1) the simpler way don't work because it maybe free many memory block twice Right, the punched holes. Forgot about them. Yeah, that's why the later failure just leaks memory. > 2) as we seen, pcpu_setup_first_chunk() doesn't cause a failure, it return 0 > always or panic by BUG_ON(), even if it fails, we can conclude the allocated > memory based on information recorded by it, such as pcpu_base_addr and many of > static variable, we can complete the free operations; but we can't if we > fail in the case pointed by this patch So, being strictly correct doesn't matter that much here. These things failing indicates that something is very wrong with either the code or configuration and we might as well trigger BUG. That said, yeah, it's nicer to recover without leaking anything. > 3) my test way is simple, i force "if (max_distance > VMALLOC_TOTAL * 3 / 4)" > to if (1) and print which memory i allocate before the jumping, then print which memory > i free after the jumping and before returning, then check whether i free the memory i > allocate in this function, the result is okay Can you please include what has been discussed into the patch description? 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>