From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 26 Oct 2006 12:08:32 -0700 (PDT) From: Christoph Lameter Subject: RE: [PATCH 3/3] hugetlb: fix absurd HugePages_Rsvd In-Reply-To: <000001c6f8b3$1d4bd020$a389030a@amr.corp.intel.com> Message-ID: References: <000001c6f8b3$1d4bd020$a389030a@amr.corp.intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: "Chen, Kenneth W" Cc: 'David Gibson' , Hugh Dickins , Andrew Morton , Bill Irwin , Adam Litke , linux-mm@kvack.org List-ID: On Wed, 25 Oct 2006, Chen, Kenneth W wrote: > I used to argue dearly on how important it is to allow parallel hugetlb > faults for scalability, but somehow lost my ground in the midst of flurry > development. Glad to see it is coming back. I wish someone would have cced me before allowing performance atrocities such as this. Performance before the "fixes" (March, 2.6.16): hsz=256M thr=100 pgs=10 min= 1370ms max=1746ms avg= 1554ms wall=1995ms cpu=155473ms hsz=256M thr=100 pgs=10 min= 1936ms max=3706ms avg= 2610ms wall=4085ms cpu=261076ms hsz=256M thr=100 pgs=10 min= 1375ms max=1988ms avg= 1600ms wall=2241ms cpu=160084ms Performance now: hsz=256M thr=10 pgs=3 min= 2965ms max=4091ms avg= 3471ms wall=4232ms cpu=34715ms hsz=256M thr=100 pgs=3 min=16268ms max=43856ms avg=35927ms wall=44561ms cpu=3592702ms hsz=256M thr=250 pgs=3 min=38348ms max=91242ms avg=74077ms wall=97071ms cpu=18519284ms Note the performance now is only using 3 instead of 10 pages. Still factor 10 down! Meaning we are now much worse than that. With David's latest parallelization attempt: hsz=256M thr=100 pgs=10 min= 1373ms max=9604ms avg= 6311ms wall=10787ms cpu=631164ms hsz=256M thr=100 pgs=10 min= 1442ms max=9115ms avg= 6386ms wall=10078ms cpu=638645ms hsz=256M thr=100 pgs=10 min= 1451ms max=10788ms avg= 7430ms wall=11357ms cpu=743070ms hsz=256M thr=100 pgs=10 min= 1439ms max=11876ms avg= 8396ms wall=13091ms cpu=839642ms Still down by a factor of 3 to 4. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org