From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <39D87F3A.7D21E18@mountain.net> Date: Mon, 02 Oct 2000 08:27:38 -0400 From: Tom Leete MIME-Version: 1.0 Subject: Re: [PATCH] fix for VM test9-pre7 References: Content-Type: multipart/mixed; boundary="------------96615B0CFDE1A7CCE0AD6CE6" Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: linux-mm@kvack.org, Linus Torvalds List-ID: This is a multi-part message in MIME format. --------------96615B0CFDE1A7CCE0AD6CE6 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Rik van Riel wrote: > > Hi, > > The attached patch seems to fix all the reported deadlock > problems with the new VM. Basically they could be grouped > into 2 categories: > > 1) __GFP_IO related locking issues > 2) something sleeps on a free/clean/inactive page goal > that isn't worked towards > > The patch has survived some heavy stresstesting on both > SMP and UP machines. I hope nobody will be able to find > a way to still crash this one ;) > > A second change is a more dynamic free memory target > (now freepages.high + inactive_target / 3), this seems > to help a little bit in some loads. > Hi, I ran lmbench on test9-pre7 with and without the patch. Test machine was a slow medium memory UP box: Cx586@120Mhz, no optimizations, 56M I still experience instability on this machine with both the patched and vanilla kernel. It usually takes the form of sudden total lockups, but on occasion I have seen oops + panic at boot. This summary doesn't show any performance advantage to the patch, but the detailed plots show that memory access latency degrades more gracefully wrt array size. For bandwidth, I'm only including the summary. Vanilla is listed first in each entry. Full lmbench report files on request. Tom --------------96615B0CFDE1A7CCE0AD6CE6 Content-Type: text/plain; charset=us-ascii; name="vanilla-vs-riel" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="vanilla-vs-riel" L M B E N C H 1 . 9 S U M M A R Y ------------------------------------ (Alpha software, do not distribute) Processor, Processes - times in microseconds - smaller is better ---------------------------------------------------------------- Host OS Mhz null null open selct sig sig fork exec sh call I/O stat clos inst hndl proc proc proc --------- ------------- ---- ---- ---- ---- ---- ----- ---- ---- ---- ---- ---- i486-linu Linux 2.4.0-t 119 1.8 4.0 51 62 0.33K 9.2 19 4.3K 16K 54K i486-linu Linux 2.4.0-p 119 1.8 4.1 51 64 0.35K 9.2 19 4.5K 16K 55K Context switching - times in microseconds - smaller is better ------------------------------------------------------------- Host OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw --------- ------------- ----- ------ ------ ------ ------ ------- ------- i486-linu Linux 2.4.0-t 2 388 1054 296 1733 439 1854 i486-linu Linux 2.4.0-p 5 308 1062 268 1650 416 1822 *Local* Communication latencies in microseconds - smaller is better ------------------------------------------------------------------- Host OS 2p/0K Pipe AF UDP RPC/ TCP RPC/ TCP ctxsw UNIX UDP TCP conn --------- ------------- ----- ----- ---- ----- ----- ----- ----- ---- i486-linu Linux 2.4.0-t 2 44 131 352 628 2267 i486-linu Linux 2.4.0-p 5 47 109 401 649 2186 File & VM system latencies in microseconds - smaller is better -------------------------------------------------------------- Host OS 0K File 10K File Mmap Prot Page Create Delete Create Delete Latency Fault Fault --------- ------------- ------ ------ ------ ------ ------- ----- ----- i486-linu Linux 2.4.0-t 110 18 337 39 2702 5 0.0K i486-linu Linux 2.4.0-p 111 20 340 42 2829 4 0.0K *Local* Communication bandwidths in MB/s - bigger is better ----------------------------------------------------------- Host OS Pipe AF TCP File Mmap Bcopy Bcopy Mem Mem UNIX reread reread (libc) (hand) read write --------- ------------- ---- ---- ---- ------ ------ ------ ------ ---- ----- i486-linu Linux 2.4.0-t 15 6 6 9 32 14 14 32 39 i486-linu Linux 2.4.0-p 14 7 6 10 32 14 14 32 39 Memory latencies in nanoseconds - smaller is better (WARNING - may not be correct, check graphs) --------------------------------------------------- Host OS Mhz L1 $ L2 $ Main mem Guesses --------- ------------- --- ---- ---- -------- ------- i486-linu Linux 2.4.0-t 119 25 419 452 No L2 cache? i486-linu Linux 2.4.0-p 119 25 365 459 --------------96615B0CFDE1A7CCE0AD6CE6-- -- 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.eu.org/Linux-MM/