Re: [PATCH] anobjrmap 9 priority mjb tree

["Martin J. Bligh" <mbligh@aracnet.com>]

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

M.

> 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
>> 
>> 
> 
>