operator-sparse Fibonacci hashing of waitqueues
PATCH 1/1 operator-sparse Fibonacci hashing of waitqueues
Quoted 2 lines
Randy, any chance you could benchmark -rmap with this on top for comparison against standard -rmap to ensure there is no regression?
System is k6-2 475 mhz and 384 MB ram with IDE disks. Here it is with a few notes on things I looked at more closely. I also have the output of readprofile between each test.
dbench 128 processes
2.4.17-rmap12f ********** 5.0 MB/sec 2.4.17-rmap12f-wli ********** 5.1 MB/sec
unixbench-4.1.0 2.4.17-rmap12f-wli 2.4.17-rmap12f
Execl Throughput 293.5 303.7 lps (3 samples) Pipe Throughput 395378.4 391759.4 lps (10 samples) Pipe-based Context Switching 78095.8 117697.0 lps (10 samples) Process Creation 1181.5 1143.0 lps (3 samples) System Call Overhead 335203.8 335211.1 lps (10 samples) Shell Scripts (1 concurrent) 586.9 591.0 lpm (3 samples)
pipe context switching in unixbench results initially looked concerning, but looking at how the test varies, and context switch and pipe tests in lmbench suggest that the lower number may not be significant.
LMbench-2.0p2 average of 9 samples.
-------------
Processor, Processes - times in microseconds - smaller is better
OS null null open slct sig sig fork exec sh
call I/O stat clos TCP inst hndl proc proc proc
2.4.17-rmap12f 0.43 0.71 3.43 5.47 49.3 1.46 3.25 904 3606 14035
2.4.17-rmap12f-wli 0.43 0.71 3.20 5.32 44.9 1.44 3.35 951 3671 13960Context switching - times in microseconds - smaller is better
OS 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K
ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw
2.4.17-rmap12f 0.91 24.52 195.18 58.21 211.57 60.72 227.85
2.4.17-rmap12f-wli 1.07 22.21 189.00 56.71 206.15 60.90 226.34*Local* Communication latencies in microseconds - smaller is better
OS Pipe AF UDP RPC/ TCP RPC/ TCP
UNIX UDP TCP conn
2.4.17-rmap12f 10.52 20.22 40.52 147.4 68.74 198.0 279.52
2.4.17-rmap12f-wli 11.06 19.85 40.39 142.1 66.52 191.3 274.65File & VM system latencies in microseconds - smaller is better
OS 0K File 10K File Mmap Prot Page
Create Delete Create Delete Latency Fault Fault
2.4.17-rmap12f 121.02 164.96 566.05 248.88 3300.3 1.18 3.8
2.4.17-rmap12f-wli 134.03 171.19 690.52 254.61 3314.6 1.17 4.0*Local* Communication bandwidths in MB/s - bigger is better
OS Pipe AF TCP File Mmap Bcopy Bcopy Mem
UNIX reread reread (libc) (hand) read
2.4.17-rmap12f 64.04 48.73 60.15 58.62 237.62 58.48 59.62 237.43 2.4.17-rmap12f-wli 64.93 41.48 42.89 62.43 237.59 58.43 59.57 237.42
The TCP and AF bandwdith numbers vary a lot between tests. Oddly, the TCP test appears to vary by almost 100% between iterations. Here are the individual test results;
OS AF TCP
UNIX
-------------------------- ----- ----- Linux 2.4.17-rmap12f 46.47 39.43 Linux 2.4.17-rmap12f 51.26 78.44 Linux 2.4.17-rmap12f 51.31 77.34 Linux 2.4.17-rmap12f 50.52 74.49 Linux 2.4.17-rmap12f 47.49 40.32 Linux 2.4.17-rmap12f 48.20 79.06 Linux 2.4.17-rmap12f 44.00 38.66 Linux 2.4.17-rmap12f 48.65 38.14 Linux 2.4.17-rmap12f 50.63 75.50 Linux 2.4.17-rmap12f-wli 43.24 39.72 Linux 2.4.17-rmap12f-wli 42.92 82.14 Linux 2.4.17-rmap12f-wli 40.96 38.19 Linux 2.4.17-rmap12f-wli 42.46 37.77 Linux 2.4.17-rmap12f-wli 44.61 38.10 Linux 2.4.17-rmap12f-wli 40.86 37.15 Linux 2.4.17-rmap12f-wli 39.26 40.63 Linux 2.4.17-rmap12f-wli 38.35 36.27 Linux 2.4.17-rmap12f-wli 40.63 36.04
The tbench test below doesn't show a large variation between the two kernels.
Memory latencies in nanoseconds - smaller is better
OS Mhz L1 $ L2 $ Main mem 2.4.17-rmap12f 476 4.20 190.41 261.95 2.4.17-rmap12f-wli 476 4.20 186.52 262.02
tiobench Average of 3 samples.
--------
2048 MB worth of files on ext2 fs. (filesize = 2048MB / num_threads) Read, write, and seek rates in MB/sec.
Latency in milliseconds.
Percent of requests that took longer than 2 and 10 seconds.
Sequential Reads Num Avg Maximum Lat% Lat% CPU Kernel Thr Rate (CPU%) Latency Latency >2s >0s Eff ------------------ --- ---------------------------------------------------- 2.4.17-rmap12f 8 9.37 13.97% 9.788 980.34 0.00000 0.00000 67 2.4.17-rmap12f-wli 8 9.38 13.74% 9.759 886.07 0.00000 0.00000 68
2.4.17-rmap12f 16 9.90 14.99% 18.234 1301.80 0.00000 0.00000 66 2.4.17-rmap12f-wli 16 9.89 14.72% 18.311 1330.12 0.00000 0.00000 67
2.4.17-rmap12f 32 10.05 16.46% 35.398 2455.18 0.00000 0.00000 61 2.4.17-rmap12f-wli 32 10.14 16.61% 35.303 2483.88 0.00000 0.00000 61
2.4.17-rmap12f 64 9.65 18.54% 71.995 4745.45 0.00000 0.00000 52 2.4.17-rmap12f-wli 64 9.65 18.29% 71.986 4792.92 0.00000 0.00000 53
2.4.17-rmap12f 128 9.25 26.66% 148.095 136165.27 4.71210 0.02498 35 2.4.17-rmap12f-wli 128 9.31 27.08% 146.307 111566.57 4.54960 0.01964 34
Random Reads Num Avg Maximum Lat% Lat% CPU Kernel Thr Rate (CPU%) Latency Latency >2s >10s Eff ------------------ --- ---------------------------------------------------- 2.4.17-rmap12f 8 0.42 1.058% 217.323 852.61 0.00000 0.00000 40 2.4.17-rmap12f-wli 8 0.42 1.073% 217.232 1016.86 0.00000 0.00000 39
2.4.17-rmap12f 16 0.48 1.406% 375.897 1485.76 0.00000 0.00000 34 2.4.17-rmap12f-wli 16 0.47 1.296% 375.872 1537.88 0.00000 0.00000 37
2.4.17-rmap12f 32 0.52 1.760% 667.107 3468.37 0.00000 0.00000 30 2.4.17-rmap12f-wli 32 0.53 1.640% 655.669 3331.63 0.00000 0.00000 32
2.4.17-rmap12f 64 0.53 2.176% 1283.121 8672.69 0.75605 0.00000 24 2.4.17-rmap12f-wli 64 0.54 1.784% 1288.162 7699.61 0.90726 0.00000 30
2.4.17-rmap12f 128 0.54 3.198% 2508.958 16549.40 5.24697 0.00000 17 2.4.17-rmap12f-wli 128 0.54 3.071% 2492.784 17542.43 5.80141 0.00000 18
Sequential Writes Num Avg Maximum Lat% Lat% CPU Kernel Thr Rate (CPU%) Latency Latency >2s >10s Eff ------------------ --- ---------------------------------------------------- 2.4.17-rmap12f 8 18.11 82.47% 4.542 4140.63 0.00000 0.00000 22 2.4.17-rmap12f-wli 8 18.06 82.49% 4.553 5403.78 0.00306 0.00000 22
2.4.17-rmap12f 16 18.04 81.69% 8.921 7486.25 0.00744 0.00000 22 2.4.17-rmap12f-wli 16 17.99 82.15% 8.893 5086.09 0.00076 0.00000 22
2.4.17-rmap12f 32 17.31 76.08% 17.610 10609.26 0.02595 0.00000 23 2.4.17-rmap12f-wli 32 17.31 77.04% 17.808 11199.52 0.03033 0.00000 22
2.4.17-rmap12f 64 15.07 60.04% 40.287 15381.66 0.39444 0.00000 25 2.4.17-rmap12f-wli 64 15.18 61.79% 40.052 20057.21 0.37003 0.00000 25
2.4.17-rmap12f 128 12.52 47.48% 95.497 31261.15 1.64452 0.00095 26 2.4.17-rmap12f-wli 128 12.62 46.73% 94.113 29901.54 1.50032 0.00114 27
Random Writes Num Avg Maximum Lat% Lat% CPU Kernel Thr Rate (CPU%) Latency Latency >2s >10s Eff ------------------ --- ---------------------------------------------------- 2.4.17-rmap12f 8 0.67 4.278% 0.490 666.50 0.00000 0.00000 16 2.4.17-rmap12f-wli 8 0.66 4.322% 0.659 688.43 0.00000 0.00000 15
2.4.17-rmap12f 16 0.68 4.492% 1.941 578.57 0.00000 0.00000 15 2.4.17-rmap12f-wli 16 0.68 4.419% 2.249 632.19 0.00000 0.00000 15
2.4.17-rmap12f 32 0.67 4.467% 0.818 835.38 0.00000 0.00000 15 2.4.17-rmap12f-wli 32 0.68 4.550% 0.663 562.35 0.00000 0.00000 15
2.4.17-rmap12f 64 0.69 4.668% 1.076 621.97 0.00000 0.00000 15 2.4.17-rmap12f-wli 64 0.69 4.585% 0.980 861.52 0.00000 0.00000 15
2.4.17-rmap12f 128 0.71 4.973% 0.975 917.19 0.00000 0.00000 14 2.4.17-rmap12f-wli 128 0.70 4.990% 0.803 940.80 0.00000 0.00000 14
bonnie++ average of 3 samples
1024MB file
Version 1.02a --------------------Sequential Output-------------------
-----Per Char----- ------Block------- -----Rewrite------ Kernel MB/sec %CPU Eff MB/sec %CPU Eff MB/sec %CPU Eff 2.4.17-rmap12f 3.38 99.0 3.41 15.12 97.0 15.58 5.14 40.7 12.64 2.4.17-rmap12f-wli 3.38 99.0 3.42 15.16 97.0 15.63 5.66 45.3 12.48
-----------Sequential Input----------- -----Random-----
-----Per Char----- ------Block------- -----Seeks------
Kernel MB/sec %CPU Eff MB/sec %CPU Eff /sec %CPU Eff
2.4.17-rmap12f 3.55 85.0 4.17 19.07 23.7 80.57 122 2.0 6096
2.4.17-rmap12f-wli 3.56 85.0 4.19 19.14 23.7 80.87 123 2.0 614016384 small files
-------------Sequential Create-------
------Create----- -----Delete-----
/sec %CPU Eff /sec %CPU Eff
2.4.17-rmap12f 4395 95.7 4594 4548 99.3 4578
2.4.17-rmap12f-wli 4214 98.3 4286 4268 91.7 4655 -------------Random Create------------
------Create----- -----Delete-----
/sec %CPU Eff /sec %CPU Eff
2.4.17-rmap12f 4460 99.0 4504 3927 93.3 4207
2.4.17-rmap12f-wli 4154 97.7 4253 4109 96.3 4265Time in seconds to build/run things.
kernel autoconf perl kernel updatedb updatedb 5x 2.4.17-rmap12f 1217 1589 1295 29 44 2.4.17-rmap12f-wli 1218 1609 1270 28 45
tbench 32 processes (average of 3 runs)
2.4.17-rmap12f ******************************** 16.3 MB/sec 2.4.17-rmap12f-wli ******************************** 16.2 MB/sec
More details on testing method and other kernels tested at
http://home.earthlink.net/~rwhron/kernel/k6-2-475.html
Signature · 1 line
Randy Hron
Quoted 2 lines · At some point in the past, I wrote:
Quoted 2 lines
Randy, any chance you could benchmark -rmap with this on top for comparison against standard -rmap to ensure there is no regression?
Quoted 3 lines · On Sun, Feb 17, 2002 at 06:01:59PM -0500, [email protected] wrote:
System is k6-2 475 mhz and 384 MB ram with IDE disks. Here it is with a few notes on things I looked at more closely. I also have the output of readprofile between each test.
Excellent! Thank you very much.
Quoted 3 lines · On Sun, Feb 17, 2002 at 06:01:59PM -0500, [email protected] wrote:
pipe context switching in unixbench results initially looked concerning, but looking at how the test varies, and context switch and pipe tests in lmbench suggest that the lower number may not be significant.
It's unclear what effect, if any, the waitqueue hashing should have on pipes and context switching in general. There are waitqueues involved but they are not associated with pages.
Quoted 3 lines · On Sun, Feb 17, 2002 at 06:01:59PM -0500, [email protected] wrote:
The TCP and AF bandwdith numbers vary a lot between tests. Oddly, the TCP test appears to vary by almost 100% between iterations. Here are the individual test results;
I'm not sure why this would be affected either, but again, it's certainly useful to check these things for unanticipated effects.
Dave, Rik, Dan, do you know of any reason why there would be an effect here (or with pipes)?
Quoted 2 lines · On Sun, Feb 17, 2002 at 06:01:59PM -0500, [email protected] wrote:
The tbench test below doesn't show a large variation between the two kernels.
This is excellent, and largely the desired result. This sort of benchmark is what I believe what would demonstrate any degradation in performance during a real workload.
More detailed analysis could show that I need to adjust the multipliers to eliminate the ones I've chosen as one of the occasional poor multipliers chosen by this process, but I have a steady and large supply of these multipliers, and these macro-throughput results seem to indicate it is almost certainly not one of those (bad ones should cause noticeable degradation, especially with the wake-all then sleep if wrong object semantics), so it's already fairly unlikely it's one of those. I'll try to get whatever hash table profiling I can on this thing as well.
Anton, Rusty, I could use help on extracting hash table stats here, I can compute confidernce intervals etc. at will but extraction...
Dave, it would be useful to hear from you on this issue as you have closer connections to machines where multiplication is expensive.
Cheers,
Bill