12% improvement in fork load from mm3 to mm4
Quoted 7 lines
autoconf build test creates about 1.2 million processes in 35 minutes. On quad xeon, there was an improvement of ~ 12% between 2.5.70-mm3 and 2.5.70-mm4.
Avg of 3 runs
2.5.70-mm3 829.0
2.5.70-mm4 737.9
profile shows the biggest change is in do_page_fault.
2.5.70-mm4 2.5.70-mm3
total 478507 521921
default_idle 229230 231410
do_page_fault 53727 103744
pte_alloc_one 22227 21114
system_call 21589 21750
kunmap_atomic 17231 17091
copy_mm 14913 13690
copy_process 14514 12789
flush_tlb_page 10946 11092
sigprocmask 9478 9038
release_task 7553 7243
exit_notify 5923 5257
copy_files 5473 5143
do_sigaction 5249 5200
sys_rt_sigprocmask 4831 4596
current_kernel_time 4729 4428
kmap_atomic 4566 4309
schedule 4430 3903
dup_task_struct 3741 3281
get_signal_to_deliver 2255 2177
do_exit 2096 1985
schedule_tail 2002 1852
ret_from_intr 1511 2298
sys_rt_sigaction 1473 1367
flush_tlb_mm 1419 1060
old_mmap 1186 1096
sys_wait4 1115 1332
setup_frame 982 550
del_timer_sync 963 968
do_flush_tlb_all 950 879
do_fork 912 768
sys_mmap2 906 844
mm_init 889 909
syscall_exit 888 951
__wake_up 886 814
flush_signal_handlers 855 758
wake_up_forked_process 845 826
mmput 842 879
put_files_struct 818 899
.text.lock.fault 808 1489
release_x86_irqs 754 505
handle_signal 677 424
wait_task_zombie 654 684
setup_sigcontext 569 285
count_open_files 525 399
copy_thread 474 407
mm_alloc 473 483
syscall_call 453 524
remove_wait_queue 449 463
error_code 446 713
restore_sigcontext 435 286
sys_sigreturn 431 373
init_new_context 424 327
get_jiffies_64 412 344
add_wait_queue 388 325
eligible_child 374 378
mm_release 369 316Signature · 2 lines
Randy Hron http://home.earthlink.net/~rwhron/kernel/bigbox.html
Quoted 10 lines · [email protected] wrote:
Quoted 8 lines
autoconf build test creates about 1.2 million processes in 35 minutes. On quad xeon, there was an improvement of ~ 12% between 2.5.70-mm3 and 2.5.70-mm4.
Avg of 3 runs
2.5.70-mm3 829.0
2.5.70-mm4 737.9profile shows the biggest change is in
do_page_fault.
Well that's amusing. In mm4 I replaced the patch which runs remap_file_pages() against all prot_exec mappings with a patch which just prefaults those mappings into pagecache.
The difference _should_ be that in mm3, all pte's are set up at mmap time. So -mm4 should have more pagefaults, not less.
Something fishy is going on there. Makes one wonder if remap_file_pages() is successfully avoiding the minor fault.