Hi > > rmap: try_to_unmap_file() required new cond_resched_rwlock(). > > To reduce code duplication, I recast cond_resched_lock() as a > > [static inline] wrapper around reworked cond_sched_lock() => > > __cond_resched_lock(void *lock, int type). > > New cond_resched_rwlock() implemented as another wrapper. > > Reader/writer locks really suck in terms of fairness and starvation, > especially when the read-side is common and frequent. (also, single > threaded performance of the read-side is worse).
Agreed. rwlock got bad performance some case. (especially on many cpu machine) if many cpu grab read-lock on and off on many cpu system. then at least 1 cpu always grab read lock and the cpu of waiting write-lock never get lock. threrefore, rwlock often make performance weakness of stress. I want know testcase for this patch and run it. Do you have it? /kosaki -- 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/