Herbert Poetzl <[EMAIL PROTECTED]> writes: > > Linux-VServer does the accounting with atomic counters, > so that works quite fine, just do the checks at the > beginning of whatever resource allocation and the > accounting once the resource is acquired ...
Atomic operations versus locks is only a granularity thing. You still need the cache line which is the cost on SMP. Are you using atomic_add_return or atomic_add_unless or are you performing you actions in two separate steps which is racy? What I have seen indicates you are using a racy two separate operation form. >> If we'll remove failcnt this would look like >> while (atomic_cmpxchg(...)) >> which is also not that good. >> >> Moreover - in RSS accounting patches I perform page list >> manipulations under this lock, so this also saves one atomic op. > > it still hasn't been shown that this kind of RSS limit > doesn't add big time overhead to normal operations > (inside and outside of such a resource container) > > note that the 'usual' memory accounting is much more > lightweight and serves similar purposes ... Perhaps.... Eric - 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/
