On Thu, 22 Sep 2016, zijun_hu wrote: > >> correct a few logic error for __insert_vmap_area() since the else > >> if condition is always true and meaningless > >> > >> in order to fix this issue, if vmap_area inserted is lower than one > >> on rbtree then walk around left branch; if higher then right branch > >> otherwise intersects with the other then BUG_ON() is triggered > >> > > > > Under normal operation, you're right that the "else if" conditional should > > always succeed: we don't want to BUG() unless there's a bug. The original > > code can catch instances when va->va_start == tmp_va->va_end where we > > should BUG(). Your code silently ignores it. > > > Hmm, the BUG_ON() appears in the original code, i don't introduce it. > it maybe be better to consider va->va_start == tmp_va->va_end as normal case > and should not BUG_ON() it since the available range of vmap_erea include > the start boundary but the end, BTW, represented as [start, end) > We don't support inserting when va->va_start == tmp_va->va_end, plain and simple. There's no reason to do so. NACK to the patch. -- 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>