RE: What is bufwaits (onstat -p)

>===== Original Message From "Mark D. Stock" <mdstock@mydas.freeserve.co.uk> ===== >"Art S. Kagel" wrote: >> >> The bufwaits indicates when a thread has to wait to read a page into a >> buffer from disk usually this is caused by the LRU Queue to which the thread >> has hashed to acquire a buffer being locked by another thread trying to do >> the same thing or needing to move a buffer from the 'clean' part of the >> queue to the 'dirty' part so it can modify the page it contains. Sometimes >> the condition is caused by buffer flushing activities for the same reason. >> Another cause is the need to latch a buffer that already contains data to >> move it to the MRU end of the queue. >> >> Increasing BUFFERS CAN help somewhat but the most effect is obtained by >> increasing LRUS which reduces the probability that there will be contention >> for the LRU that the thread hashes to (or the ones that it rehashes to >> after spinning for too long). If there is still LRU contention even after >> maxing LRUS out (128 in 7.[123]x) > >I thought the max LRUS was 256 for 32 bit? The max LRUS is certainly 512 >for 64 bit. :-) > >The maximum number of page cleaners is 128. Perhaps this is were you got >128? You configure LRU's to 128, but if you count the FLRU's and MLRU's separately you end up with 256... Will ------------------------------------------------------------ This e-mail has been sent to you courtesy of OperaMail, as a free service from Opera Software, makers of the award-winning Web Browser, Opera. Visit us at http://www.opera.com/ or our portal at: http://www.myopera.com/ Your free e-mail account is waiting at: http://www.operamail.com/ ------------------------------------------------------------