From: Martin J. B. <mb...@ar...> - 2003-02-17 00:44:56
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OK, so I guess we all know that ext3 doesn't scale well. But by accident, I have some numbers on exactly how bad it really is: Kernbench-2: (make -j N vmlinux, where N = 2 x num_cpus) Elapsed User System CPU 2.5.61-mjb0.1-ext3 48.47 564.13 143.16 1458.67 2.5.61-mjb0.1-ext2 46.06 563.04 115.36 1472.33 (look at system time ... eeek!) diffprofile (+ is worse with ext3, - better) 12702 .text.lock.inode 7786 default_idle 1706 ext3_dirty_inode 1694 start_this_handle 1636 ext3_do_update_inode 1304 .text.lock.dir 983 journal_add_journal_head 903 __find_get_block_slow 797 .text.lock.sem 630 __mark_inode_dirty 567 __brelse 537 __find_get_block 523 __wake_up 459 ext3_get_inode_loc 454 find_get_page 434 __blk_queue_bounce 382 generic_fillattr 360 fd_install 357 do_get_write_access 308 d_lookup 290 vfs_read 289 do_anonymous_page 272 dput 267 file_ra_state_init 249 journal_get_write_access 243 page_remove_rmap 222 link_path_walk 220 may_open 195 vm_enough_memory 189 ext3_readdir 186 journal_stop 185 journal_dirty_metadata 152 __fput 148 update_atime 110 zap_pte_range 105 .text.lock.sched 100 fput 96 buffered_rmqueue 95 filemap_nopage 93 ext3_prepare_write 90 page_add_rmap 86 find_next_usable_block 76 block_write_full_page 71 journal_cancel_revoke 70 bh_lru_install 65 journal_unlock_journal_head 64 .text.lock.namei 63 do_page_cache_readahead 61 log_space_left 61 ext3_check_dir_entry 59 __copy_from_user_ll 58 kfree 58 journal_commit_transaction 54 kmem_cache_free 54 do_sync_read 54 .text.lock.char_dev 50 ext3_get_block_handle ... -52 find_vma -58 page_address -58 get_empty_filp -60 do_generic_mapping_read -74 ext2_readdir -85 generic_file_open -87 atomic_dec_and_lock -109 file_move -513 dentry_open -1468 follow_mount -2091 .text.lock.file_table |
From: Dave H. <hav...@us...> - 2003-02-17 01:19:45
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Martin J. Bligh wrote: > OK, so I guess we all know that ext3 doesn't scale well. But by > accident, I have some numbers on exactly how bad it really is: > > Kernbench-2: (make -j N vmlinux, where N = 2 x num_cpus) > Elapsed User System CPU > 2.5.61-mjb0.1-ext3 48.47 564.13 143.16 1458.67 > 2.5.61-mjb0.1-ext2 46.06 563.04 115.36 1472.33 > > (look at system time ... eeek!) > > diffprofile (+ is worse with ext3, - better) > > 12702 .text.lock.inode # grep -c lock_kernel fs/ext3/inode.c 35 -- Dave Hansen hav...@us... |
From: Andrew M. <ak...@di...> - 2003-02-17 01:29:00
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"Martin J. Bligh" <mb...@ar...> wrote: > > (look at system time ... eeek!) Can we just say that ext3's talents lie elsewhere? I've got some stuff which helps a bit, but nobody has had the time to implement the significant overhaul which is needed here. noatime would help. |