On Mon, Jul 26, 2010 at 11:28:18AM +0200, Andre Przywara wrote: > When the mbind() syscall implementation processes the node mask > provided by the user, the last node is accidentally masked out. > This is present since the dawn of time (aka Before Git), I guess > nobody realized that because libnuma as the most prominent user of > mbind() uses large masks (sizeof(long)) and nobody cared if the > 64th node is not handled properly. But if the user application > defers the masking to the kernel and provides the number of valid bits > in maxnodes, there is always the last node missing. > However this also affect the special case with maxnodes=0, the manpage > reads that mbind(ptr, len, MPOL_DEFAULT, &some_long, 0, 0); should > reset the policy to the default one, but in fact it returns EINVAL. > This patch just removes the decrease-by-one statement, I hope that > there is no workaround code in the wild that relies on the bogus > behavior. Actually libnuma and likely most existing users rely on it. The only way to change it would be to add new system calls. -Andi -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>