2012/7/17 Michal Nazarewicz <[email protected]>: > Joonsoo Kim <[email protected]> writes: > >> migrate_pages() would return positive value in some failure case, >> so 'ret > 0 ? 0 : ret' may be wrong. >> This fix it and remove one dead statement. >> >> Signed-off-by: Joonsoo Kim <[email protected]> >> Cc: Michal Nazarewicz <[email protected]> >> Cc: Marek Szyprowski <[email protected]> >> Cc: Minchan Kim <[email protected]> >> Cc: Christoph Lameter <[email protected]> > > Have you actually encountered this problem? If migrate_pages() fails > with a positive value, the code that you are removing kicks in and > -EBUSY is assigned to ret (now that I look at it, I think that in the > current code the "return ret > 0 ? 0 : ret;" statement could be reduced > to "return ret;"). Your code seems to be cleaner, but the commit > message does not look accurate to me. >
I don't encounter this problem yet. If migrate_pages() with offlining false meets KSM page, then migration failed. In this case, failed page is removed from cc.migratepage list and return failed count. So it can be possible exiting loop without testing ++tries == 5 and ret is over the zero. Is there any point which I missing? Is there any possible scenario "migrate_pages return > 0 and cc.migratepages is empty"? I'm not expert for MM, so please comment my humble opinion. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
