Messages in this thread | | | Date | Mon, 18 Nov 2002 09:53:24 -0800 | From | Dave Hansen <> | Subject | Re: unusual scheduling performance |
| |
William Lee Irwin III wrote: > On Mon, Nov 18, 2002 at 08:34:34AM -0800, Martin J. Bligh wrote: > >>1. make -j <what?> >>2. profiles? >>3. Can you try the latest set of NUMA sched patches posted by Eric Focht? > > (1) make -j64 bzImage > (2) doesn't sound useful for load balancing > (3) sure
I'm seeing the same thing. In my pagecache warmup test, I do 20 greps to pull in a 10-gig fileset. Each grep works on 1/20th of the files.
For a long, long time, one the file set was warmed up, the time to do the test took ~14 secdonds: Average Real: 14.0824 Average User: 0.94055 Average Sys: 5.20875 Full profile here: http://www.sr71.net/prof/grep/run-grep-warm-2.5.47-11-15-2002-15.21.31/
As of 2.5.47, it looks like this: Average Real: 18.9168 Average User: 1.0073 Average Sys: 4.9918 Full profile here: http://www.sr71.net/prof/grep/run-grep-warm-2.5.47-11-15-2002-15.58.02/
readprofile ticks ------------------ fast slow diff page_cache_readahead: 93 82 -11 __generic_file_aio_read: 73 83 10 file_move: 52 86 34 dget_locked: 57 87 30 proc_pid_stat: 149 88 -61 ep_notify_file_close: 59 89 30 get_pid_list: 21 91 70 update_atime: 100 93 -7 get_unused_fd: 23 105 82 fget: 120 113 -7 dput: 100 120 20 get_empty_filp: 105 121 16 system_call: 113 129 16 rwsem_down_write_failed: 133 133 vfs_follow_link: 116 164 48 file_read_actor: 198 227 29 __fput: 178 241 63 radix_tree_lookup: 324 293 -31 atomic_dec_and_lock: 229 307 78 .text.lock.dec_and_lock: 111 331 220 try_to_wake_up: 374 374 kmap_atomic: 346 398 52 kunmap_atomic: 379 409 30 vfs_read: 440 431 -9 .text.lock.namei: 149 482 333 __d_lookup: 456 518 62 link_path_walk: 533 710 177 schedule: 1 1060 1059 do_generic_mapping_read: 1880 1846 -34 poll_idle: 2059 33416 31357 __copy_to_user: 94208 87678 -6530 total: 104173 132206 28033
So, schedule() is being called a _lot_ more. But, for some reason, the slower one wasn't caught doing __copy_to_user() as much.
Bill, does this look like what you're seeing? -- Dave Hansen haveblue@us.ibm.com
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |