Messages in this thread | | | Subject | Re: Serious Kernel slowdown with HIMEM (4Gig) in 2.6.7 | Date | Sat, 14 Aug 2004 12:43:11 -0400 | From | "Lawrence E. Freil" <> |
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On Sat Aug 14th, Martin J. Bligh wrote: >Does time indicate more systime or user time? If it's systime (probably is) >please take a kernel profile of each (see Documentation/basic_profiling.txt). >That'll give us a much better clue what's going on. > >M.
Martin, the time is almost exclusively listed as "user" in the the "time" results:
FAST (with mem=800M): time ls -laR /home/groups/sysmbase >/dev/null
real 0m0.122s user 0m0.101s sys 0m0.021s
SLOW (without mem=800M): time ls -laR /home/groups/sysmbase >/dev/null real 0m5.175s user 0m5.145s sys 0m0.030s
Though there is a consistant sys component that is slightly higher. I ran profiles three times for "fast" and three times for "slow". Here they are
FAST profile 1: 33 __do_softirq 0.2578 1 groups_search 0.0094 1 in_group_p 0.0085 1 do_mmap_pgoff 0.0006 5 __d_lookup 0.0208 1 xfs_dir2_leaf_getdents 0.0003 1 xfs_trans_brelse 0.0035 6 strncpy_from_user 0.0606 49 total 0.0000
FAST profile 2: 3 system_call 0.0682 1 do_page_fault 0.0008 1 groups_search 0.0094 1 sys_lstat64 0.0175 1 follow_mount 0.0073 1 do_lookup 0.0062 3 link_path_walk 0.0015 5 __d_lookup 0.0208 2 write_profile 0.0312 1 xfs_dir2_put_dirent64_direct 0.0067 1 xfs_dir2_put_dirent64_uio 0.0049 1 xfs_dir2_leaf_getdents 0.0003 4 strncpy_from_user 0.0404 1 __copy_user_intel 0.0058 1 __copy_to_user_ll 0.0093 27 total 0.0000
FAST profile 3: 2 system_call 0.0455 1 groups_search 0.0094 1 in_group_p 0.0085 1 buffered_rmqueue 0.0028 1 find_vma_prev 0.0123 1 cp_new_stat64 0.0037 2 follow_mount 0.0146 4 link_path_walk 0.0020 2 dput 0.0058 4 __d_lookup 0.0167 1 de_put 0.0097 3 write_profile 0.0469 2 strncpy_from_user 0.0202 1 __copy_user_intel 0.0058 26 total 0.0000
And here are the three "SLOW" profiles:
SLOW profile 1: 4 system_call 0.0909 2 groups_search 0.0189 1 free_hot_cold_page 0.0043 1 kmem_cache_alloc 0.0089 1 kmem_cache_free 0.0132 1 __pagevec_lru_add_active 0.0060 1 do_wp_page 0.0013 1 do_anonymous_page 0.0027 3 do_no_page 0.0040 1 vfs_getattr 0.0065 2 follow_mount 0.0146 2 do_lookup 0.0124 5 link_path_walk 0.0024 1 path_lookup 0.0030 1 dput 0.0029 6 __d_lookup 0.0250 3 write_profile 0.0469 1 xfs_bmapi 0.0002 1 xfs_dir2_block_getdents 0.0012 2 strncpy_from_user 0.0202 2 __copy_user_intel 0.0116 7 __copy_to_user_ll 0.0648 49 total 0.0000
SLOW profile 2: 2 system_call 0.0455 2 do_page_fault 0.0015 1 zap_pte_range 0.0017 1 do_anonymous_page 0.0027 2 do_no_page 0.0027 1 follow_mount 0.0073 1 do_lookup 0.0062 4 link_path_walk 0.0020 1 filldir64 0.0043 10 __d_lookup 0.0417 3 write_profile 0.0469 1 linvfs_getattr 0.0159 4 strncpy_from_user 0.0404 1 __copy_user_intel 0.0058 3 __copy_to_user_ll 0.0278 1 ata_interrupt 0.0037 38 total 0.0000
SLOW profile 3: 4 system_call 0.0909 1 __might_sleep 0.0063 1 in_group_p 0.0085 1 wake_up_page 0.0175 1 prep_new_page 0.0123 1 kmem_cache_free 0.0132 2 do_no_page 0.0027 1 sys_llseek 0.0051 1 vfs_getattr 0.0065 1 getname 0.0041 3 link_path_walk 0.0015 1 path_lookup 0.0030 10 __d_lookup 0.0417 2 write_profile 0.0312 1 xfs_da_brelse 0.0034 1 xfs_dir2_put_dirent64_direct 0.0067 4 strncpy_from_user 0.0404 4 __copy_user_intel 0.0233 2 __copy_to_user_ll 0.0185 42 total 0.0000
Hope this helps.
-- Lawrence Freil Email:lef@freil.com 1768 Old Country Place Phone:(770) 667-9274 Woodstock, GA 30188
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