Re: [PATCH] SLUB use cmpxchg_local

[Mathieu Desnoyers <compudj@krystal.dyndns.org>]

Reformatting...

* Mathieu Desnoyers (compudj@krystal.dyndns.org) wrote:
> Hi Christoph,
> 
> If you are interested in the raw numbers:
> 
> The (very basic) test module follows. Make sure you change get_cycles()
> for get_cycles_sync() if you plan to run this on x86_64.
> 
> (tests taken on a 3GHz Pentium 4)
> 

(Note: test 1 uses the kfree slow path, as figured out by
instrumentation)

SLUB Performance testing
========================
1. Kmalloc: Repeatedly allocate then free test

* slub HEAD, test 1
kmalloc(8) = 201 cycles	    kfree = 351 cycles
kmalloc(16) = 198 cycles	  kfree = 359 cycles
kmalloc(32) = 200 cycles	  kfree = 381 cycles
kmalloc(64) = 224 cycles	  kfree = 394 cycles
kmalloc(128) = 285 cycles	  kfree = 424 cycles
kmalloc(256) = 411 cycles	  kfree = 546 cycles
kmalloc(512) = 480 cycles	  kfree = 619 cycles
kmalloc(1024) = 623 cycles	kfree = 750 cycles
kmalloc(2048) = 686 cycles	kfree = 811 cycles
kmalloc(4096) = 482 cycles	kfree = 538 cycles
kmalloc(8192) = 680 cycles	kfree = 734 cycles
kmalloc(16384) = 713 cycles	kfree = 843 cycles

* Slub HEAD, test 2
kmalloc(8) = 190 cycles	    kfree = 351 cycles
kmalloc(16) = 195 cycles	  kfree = 360 cycles
kmalloc(32) = 201 cycles	  kfree = 370 cycles
kmalloc(64) = 245 cycles	  kfree = 389 cycles
kmalloc(128) = 283 cycles	  kfree = 413 cycles
kmalloc(256) = 409 cycles	  kfree = 547 cycles
kmalloc(512) = 476 cycles	  kfree = 616 cycles
kmalloc(1024) = 628 cycles	kfree = 753 cycles
kmalloc(2048) = 684 cycles	kfree = 811 cycles
kmalloc(4096) = 480 cycles	kfree = 539 cycles
kmalloc(8192) = 661 cycles	kfree = 746 cycles
kmalloc(16384) = 741 cycles	kfree = 856 cycles

* cmpxchg_local Slub test
kmalloc(8) = 83 cycles	    kfree = 363 cycles
kmalloc(16) = 85 cycles	    kfree = 372 cycles
kmalloc(32) = 92 cycles	    kfree = 377 cycles
kmalloc(64) = 115 cycles	  kfree = 397 cycles
kmalloc(128) = 179 cycles	  kfree = 438 cycles
kmalloc(256) = 314 cycles	  kfree = 564 cycles
kmalloc(512) = 398 cycles	  kfree = 615 cycles
kmalloc(1024) = 573 cycles	kfree = 745 cycles
kmalloc(2048) = 629 cycles	kfree = 816 cycles
kmalloc(4096) = 473 cycles	kfree = 548 cycles
kmalloc(8192) = 659 cycles	kfree = 745 cycles
kmalloc(16384) = 724 cycles	kfree = 843 cycles



2. Kmalloc: alloc/free test

* slub HEAD, test 1
kmalloc(8)/kfree = 322 cycles
kmalloc(16)/kfree = 318 cycles
kmalloc(32)/kfree = 318 cycles
kmalloc(64)/kfree = 325 cycles
kmalloc(128)/kfree = 318 cycles
kmalloc(256)/kfree = 328 cycles
kmalloc(512)/kfree = 328 cycles
kmalloc(1024)/kfree = 328 cycles
kmalloc(2048)/kfree = 328 cycles
kmalloc(4096)/kfree = 678 cycles
kmalloc(8192)/kfree = 1013 cycles
kmalloc(16384)/kfree = 1157 cycles

* Slub HEAD, test 2
kmalloc(8)/kfree = 323 cycles
kmalloc(16)/kfree = 318 cycles
kmalloc(32)/kfree = 318 cycles
kmalloc(64)/kfree = 318 cycles
kmalloc(128)/kfree = 318 cycles
kmalloc(256)/kfree = 328 cycles
kmalloc(512)/kfree = 328 cycles
kmalloc(1024)/kfree = 328 cycles
kmalloc(2048)/kfree = 328 cycles
kmalloc(4096)/kfree = 648 cycles
kmalloc(8192)/kfree = 1009 cycles
kmalloc(16384)/kfree = 1105 cycles

* cmpxchg_local Slub test
kmalloc(8)/kfree = 112 cycles
kmalloc(16)/kfree = 103 cycles
kmalloc(32)/kfree = 103 cycles
kmalloc(64)/kfree = 103 cycles
kmalloc(128)/kfree = 112 cycles
kmalloc(256)/kfree = 111 cycles
kmalloc(512)/kfree = 111 cycles
kmalloc(1024)/kfree = 111 cycles
kmalloc(2048)/kfree = 121 cycles
kmalloc(4096)/kfree = 650 cycles
kmalloc(8192)/kfree = 1042 cycles
kmalloc(16384)/kfree = 1149 cycles

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68