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SubjectRe: [PATCH] anobjrmap 9 priority mjb tree

> > Does SDET use mremap a lot ? Hugh added i_shared_sem in mremap -> move_vma
> > -> move_page_tables path to avoid orphaned ptes due to mremap vs. truncate
> > race. That may be the reason for the slowdown, I am not sure.
>
> I don't think so .... I presume you're just holding the sem for longer
> during normal operations due to the more complex data structure.

I haven't done any benchmarks with prio_tree. I just tried kernel compile
which was not bad. I tried rmap-test.c and test-mmap3.c. The results were
not bad on UP. I didn't try them on SMP, so you can be right.

> This was just with vs without the prio tree patch, so Hughs's changes
> were in both sets ...

The change I mentioned above was added only in Hugh's prio_tree patch,
it was not there before. However, I was just guessing that the mremap
change can be a reason. It can very well be due to prio_tree complexity.
I don't have any data to prove or disprove either way.

Rajesh


> > On Fri, 9 Apr 2004, Martin J. Bligh wrote:
> >
> >> > This anobjrmap 9 (or anon_mm9) patch adds Rajesh's radix priority search
> >> > tree on top of Martin's 2.6.5-rc3-mjb2 tree, making a priority mjb tree!
> >> > Approximately equivalent to Andrea's 2.6.5-aa1, but using anonmm instead
> >> > of anon_vma, and of course each tree has its own additional features.
> >>
> >> This slows down kernel compile a little, but worse, it slows down SDET
> >> by about 25% (on the 16x). I think you did something horrible to sem
> >> contention ... presumably i_shared_sem, which SDET was fighting with
> >> as it was anyway ;-(
> >>
> >> Diffprofile shows:
> >>
> >>
> >> 122626 15.7% total
> >> 44129 790.0% __down
> >> 20988 4.1% default_idle
> >> 12101 550.3% __wake_up
> >> 11723 489.1% finish_task_switch
> >> 6988 77.4% do_wp_page
> >> 3983 21.7% copy_page_range
> >> 2683 19.2% zap_pte_range
> >> 2325 54.3% do_anonymous_page
> >> 2293 73.1% copy_mm
> >> 1787 68.3% remove_shared_vm_struct
> >> 1768 101.6% pte_alloc_one
> >> 1564 40.0% do_no_page
> >> 1520 50.8% do_page_fault
> >> 1376 39.2% clear_page_tables
> >> 1282 63.4% __copy_user_intel
> >> 926 9.4% page_remove_rmap
> >> 878 13.1% __copy_to_user_ll
> >> 835 46.8% __block_prepare_write
> >> 788 35.8% copy_process
> >> 777 0.0% __vma_prio_tree_remove
> >> 761 48.8% buffered_rmqueue
> >> 740 48.6% free_hot_cold_page
> >> 674 128.4% vma_link
> >> 641 0.0% __vma_prio_tree_insert
> >> 612 941.5% sched_clock
> >> 585 0.0% prio_tree_insert
> >> 563 60.4% exit_notify
> >> 547 225.1% split_vma
> >> 539 6.4% release_pages
> >> 534 464.3% schedule
> >> 495 32.0% release_task
> >> 422 148.1% flush_signal_handlers
> >> 421 66.6% find_vma
> >> 420 79.5% set_page_dirty
> >> 409 60.1% fput
> >> 359 44.5% __copy_from_user_ll
> >> 319 47.6% do_mmap_pgoff
> >> 290 254.4% find_vma_prepare
> >> 270 167.7% rb_insert_color
> >> 254 61.7% pte_alloc_map
> >> 251 91.3% exit_mmap
> >> 229 23.2% __read_lock_failed
> >> 228 9.9% filemap_nopage
> >> ...
> >> -100 -29.3% group_reserve_blocks
> >> -107 -53.5% .text.lock.namespace
> >> -107 -18.4% render_sigset_t
> >> -126 -18.7% mmgrab
> >> -146 -10.9% generic_file_open
> >> -166 -9.5% ext2_new_inode
> >> -166 -38.1% d_path
> >> -166 -20.1% __find_get_block_slow
> >> -173 -20.7% proc_pid_status
> >> -182 -19.3% update_atime
> >> -185 -25.8% fd_install
> >> -202 -13.8% .text.lock.highmem
> >> -221 -14.5% __fput
> >> -225 -14.3% number
> >> -257 -14.2% proc_pid_stat
> >> -284 -21.6% file_kill
> >> -290 -35.3% proc_root_link
> >> -300 -36.5% ext2_new_block
> >> -349 -61.7% .text.lock.base
> >> -382 -48.0% proc_check_root
> >> -412 -19.4% path_release
> >> -454 -20.0% file_move
> >> -462 -32.2% lookup_mnt
> >> -515 -4.5% find_get_page
> >> -547 -34.5% .text.lock.dcache
> >> -689 -31.2% follow_mount
> >> -940 -33.8% .text.lock.dec_and_lock
> >> -1043 -51.6% .text.lock.file_table
> >> -1115 -9.9% __d_lookup
> >> -1226 -20.1% path_lookup
> >> -1305 -61.5% grab_block
> >> -2101 -29.8% atomic_dec_and_lock
> >> -2554 -40.3% .text.lock.filemap
> >>
> >>
> >
> >
>
>
>
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