With the ATI bug I was hitting earlier fixed, only my btrfs partition
continues to show high cpu usage for some operations.
Rsync, git pull, git checkout and svn up are typicall operations which
trigger the high cpu usage.
As an example, this perf report is from using git checkout to change to
a new branch; the change needed to checkout 208 files out of about 1600
total files. du(1) reports that the checkout is about 14 megs; the
alternates for that tree have about 60 megs of git packs.
As you can see btrfs_find_space_cluster(), find_next_bit() and
find_next_zero_bit() use most of the sys cpu. That patterns seems to
hold whenever I run perf top during such operations.
Box is x86_32, pentium3m.
# Samples: 11372
#
# Overhead Command Shared Object Symbol
# ........ ....... .................. ......
#
42.75% git [kernel] [k] btrfs_find_space_cluster
34.59% git [kernel] [k] find_next_bit
14.01% git [kernel] [k] find_next_zero_bit
0.76% git libz.so.1.2.3 [.] inflate_fast
0.42% git [kernel] [k] find_extent_buffer
0.34% git [kernel] [k] find_free_extent
0.28% git git [.] blk_SHA1_Block
0.26% git libz.so.1.2.3 [.] adler32
0.26% git [kernel] [k] test_range_bit
0.23% git [kernel] [k] scsi_dispatch_cmd
0.22% git [kernel] [k] div64_u64
0.21% git [kernel] [k] generic_bin_search
0.20% git [kernel] [k] __do_softirq
0.16% git [kernel] [k] get_page_from_freelist
0.16% git [ehci_hcd] [k] 0x00000000003c25
0.15% git [kernel] [k] read_extent_buffer
0.14% git [kernel] [k] btrfs_return_cluster_to_free_space
0.12% git [kernel] [k] btrfs_search_slot
0.12% git [kernel] [k] map_private_extent_buffer
0.11% git [kernel] [k] btrfs_clear_path_blocking
0.11% git [kernel] [k] set_extent_bit
0.11% git [kernel] [k] tree_search_offset
0.11% git [kernel] [k] __copy_from_user_ll
0.11% git git [.] patch_delta
0.08% git [kernel] [k] kmem_cache_alloc
0.08% git [kernel] [k] btrfs_alloc_from_cluster
0.08% git [kernel] [k] memmove
0.07% git [kernel] [k] __queue_work
0.07% git [kernel] [k] __extent_read_full_page
0.07% git [kernel] [k] alloc_extent_buffer
0.07% git [kernel] [k] scsi_request_fn
0.06% git libz.so.1.2.3 [.] inflate_table
0.06% git [kernel] [k] btrfs_unlock_up_safe
0.06% git [kernel] [k] memcpy_extent_buffer
0.06% git [kernel] [k] tree_insert
0.06% git [kernel] [k] __make_request
0.05% git [kernel] [k] block_group_cache_tree_search
0.05% git [kernel] [k] verify_parent_transid
0.05% git [kernel] [k] map_extent_buffer
0.04% git [kernel] [k] btrfs_header_nritems
0.04% git [kernel] [k] btrfs_tree_unlock
0.04% git [kernel] [k] do_page_fault
0.04% git libz.so.1.2.3 [.] .L207
0.04% git libz.so.1.2.3 [.] .L213
0.04% git git [.] cache_name_compare
0.04% git [kernel] [k] __rcu_process_callbacks
0.04% git [kernel] [k] __set_page_dirty_nobuffers
0.04% git [kernel] [k] kmem_cache_alloc_notrace
0.04% git [kernel] [k] bin_search
0.04% git [kernel] [k] unlock_up
0.04% git [kernel] [k] btrfs_reserve_extent
0.04% git [kernel] [k] btrfs_item_offset
0.04% git [kernel] [k] unmap_extent_buffer
0.04% git [kernel] [k] radix_tree_lookup_slot
0.04% git [kernel] [k] __lookup
0.04% git [kernel] [k] rb_erase
0.04% git [kernel] [k] tcp_transmit_skb
0.03% git libc-2.11.so [.] _int_malloc
0.03% git git [.] make_traverse_path
0.03% git [kernel] [k] __wake_up_bit
0.03% git [kernel] [k] handle_IRQ_event
0.03% git [kernel] [k] filemap_fault
0.03% git [kernel] [k] __remove_mapping
0.03% git [kernel] [k] __d_lookup
0.03% git [kernel] [k] btrfs_release_path
0.03% git [kernel] [k] btrfs_lock_root_node
0.03% git [kernel] [k] btrfs_put_block_group
0.03% git [kernel] [k] __btrfs_free_extent
0.03% git [kernel] [k] btrfs_mark_buffer_dirty
0.03% git [kernel] [k] inode_tree_add
0.03% git [kernel] [k] __tree_search
0.03% git [kernel] [k] btrfs_key_blockptr
0.03% git [kernel] [k] try_release_extent_buffer
0.03% git [kernel] [k] btrfs_tree_lock
0.03% git [kernel] [k] spin_unlock
0.03% git [kernel] [k] find_ref_head
0.03% git [kernel] [k] rb_next
0.02% git libc-2.11.so [.] _IO_vfprintf_internal
0.02% git libc-2.11.so [.] _IO_default_xsputn_internal
0.02% git git [.] git_checkattr
0.02% git git [.] df_name_compare
0.02% git git [.] write_index
0.02% git git [.] unpack_callback
0.02% git git [.] twoway_merge
0.02% git [vdso] [.] 0x000000ffffe425
0.02% git [kernel] [k] check_for_new_grace_period
0.02% git [kernel] [k] __rcu_read_unlock
0.02% git [kernel] [k] unlock_page
0.02% git [kernel] [k] add_to_page_cache_locked
0.02% git [kernel] [k] release_pages
0.02% git [kernel] [k] unmap_vmas
0.02% git [kernel] [k] find_vma
0.02% git [kernel] [k] kfree
0.02% git [kernel] [k] fd_install
0.02% git [kernel] [k] pipe_read
0.02% git [kernel] [k] do_lookup
0.02% git [kernel] [k] link_path_walk
0.02% git [kernel] [k] dput
0.02% git [kernel] [k] inode_init_always
0.02% git [kernel] [k] find_inode
0.02% git [kernel] [k] __btrfs_cow_block
0.02% git [kernel] [k] btrfs_reduce_alloc_profile
0.02% git [kernel] [k] lookup_inline_extent_backref
0.02% git [kernel] [k] btree_read_extent_buffer_pages
0.02% git [kernel] [k] btrfs_inode_sequence
0.02% git [kernel] [k] free_extent_buffer
0.02% git [kernel] [k] merge_state
0.02% git [kernel] [k] insert_state
0.02% git [kernel] [k] clear_extent_bit
0.02% git [kernel] [k] write_extent_buffer
0.02% git [kernel] [k] btrfs_clear_lock_blocking
0.02% git [kernel] [k] security_inode_alloc
0.02% git [kernel] [k] chksum_update
0.02% git [kernel] [k] generic_make_request
0.02% git [kernel] [k] get_request
0.02% git [kernel] [k] yenta_interrupt
0.02% git [kernel] [k] acpi_pm_read
0.01% git libz.so.1.2.3 [.] .L212
0.01% git libz.so.1.2.3 [.] .L211
0.01% git libc-2.11.so [.] __GI_getenv
0.01% git libc-2.11.so [.] _itoa_word
0.01% git libc-2.11.so [.] __GI_fflush
0.01% git libc-2.11.so [.] __fopen_internal
0.01% git libc-2.11.so [.] __calloc
0.01% git libc-2.11.so [.] __GI_strlen
0.01% git ld-2.11.so [.] _dl_relocate_object
0.01% git git [.] convert_to_working_tree
0.01% git git [.] checkout_entry
0.01% git git [.] add_name_hash
0.01% git git [.] display
0.01% git git [.] verify_path
0.01% git git [.] ce_write
0.01% git git [.] read_index_from
0.01% git git [.] add_entry
0.01% git git [.] git_inflate
0.01% git [kernel] [k] ptregs_execve
0.01% git [kernel] [k] run_timer_softirq
0.01% git [kernel] [k] mod_timer
0.01% git [kernel] [k] wake_up_bit
0.01% git [kernel] [k] prepare_to_wait
0.01% git [kernel] [k] __rcu_read_lock
0.01% git [kernel] [k] rcu_start_gp
0.01% git [kernel] [k] rcu_process_callbacks
0.01% git [kernel] [k] mempool_alloc
0.01% git [kernel] [k] __alloc_pages_nodemask
0.01% git [kernel] [k] free_hot_cold_page
0.01% git [kernel] [k] activate_page
0.01% git [kernel] [k] mark_page_accessed
0.01% git [kernel] [k] ____pagevec_lru_add
0.01% git [kernel] [k] __lru_cache_add
0.01% git [kernel] [k] lru_add_drain
0.01% git [kernel] [k] put_page
0.01% git [kernel] [k] invalidate_mapping_pages
0.01% git [kernel] [k] page_add_new_anon_rmap
0.01% git [kernel] [k] generic_fillattr
0.01% git [kernel] [k] cp_new_stat64
0.01% git [kernel] [k] path_init
0.01% git [kernel] [k] path_put
0.01% git [kernel] [k] path_to_nameidata
0.01% git [kernel] [k] path_walk
0.01% git [kernel] [k] do_unlinkat
0.01% git [kernel] [k] _d_rehash
0.01% git [kernel] [k] d_alloc
0.01% git [kernel] [k] hash
0.01% git [kernel] [k] iput
0.01% git [kernel] [k] inode_init_once
0.01% git [kernel] [k] clear_inode
0.01% git [kernel] [k] ifind
0.01% git [kernel] [k] bio_alloc_bioset
0.01% git [kernel] [k] locks_remove_posix
0.01% git [kernel] [k] dtSearch
0.01% git [kernel] [k] metapage_get_blocks
0.01% git [kernel] [k] check_block
0.01% git [kernel] [k] btrfs_set_path_blocking
0.01% git [kernel] [k] btrfs_alloc_path
0.01% git [kernel] [k] read_block_for_search
0.01% git [kernel] [k] update_ref_for_cow
0.01% git [kernel] [k] read_node_slot
0.01% git [kernel] [k] btrfs_leaf_free_space
0.01% git [kernel] [k] btrfs_insert_empty_items
0.01% git [kernel] [k] pin_down_bytes
0.01% git [kernel] [k] update_block_group
0.01% git [kernel] [k] run_one_delayed_ref
0.01% git [kernel] [k] btrfs_free_extent
0.01% git [kernel] [k] btrfs_find_block_group
0.01% git [kernel] [k] btrfs_lookup_dir_index_item
0.01% git [kernel] [k] btrfs_lookup_inode
0.01% git [kernel] [k] btrfs_find_tree_block
0.01% git [kernel] [k] btrfs_set_buffer_uptodate
0.01% git [kernel] [k] btrfs_find_create_tree_block
0.01% git [kernel] [k] btrfs_buffer_uptodate
0.01% git [kernel] [k] clean_tree_block
0.01% git [kernel] [k] wait_current_trans
0.01% git [kernel] [k] __btrfs_end_transaction
0.01% git [kernel] [k] start_transaction
0.01% git [kernel] [k] btrfs_set_page_dirty
0.01% git [kernel] [k] init_btrfs_i
0.01% git [kernel] [k] btrfs_merge_bio_hook
0.01% git [kernel] [k] btrfs_get_extent
0.01% git [kernel] [k] btrfs_add_link
0.01% git [kernel] [k] btrfs_delete_inode
0.01% git [kernel] [k] btrfs_clear_bit_hook
0.01% git [kernel] [k] lookup_extent_mapping
0.01% git [kernel] [k] btrfs_file_extent_num_bytes
0.01% git [kernel] [k] btrfs_dir_name_len
0.01% git [kernel] [k] btrfs_dir_data_len
0.01% git [kernel] [k] btrfs_key_generation
0.01% git [kernel] [k] btrfs_timespec_nsec
0.01% git [kernel] [k] btrfs_timespec_sec
0.01% git [kernel] [k] btrfs_inode_mode
0.01% git [kernel] [k] btrfs_inode_nbytes
0.01% git [kernel] [k] btrfs_set_item_size
0.01% git [kernel] [k] btrfs_set_item_offset
0.01% git [kernel] [k] btrfs_set_extent_flags
0.01% git [kernel] [k] btrfs_set_timespec_sec
0.01% git [kernel] [k] btrfs_set_inode_block_group
0.01% git [kernel] [k] extent_io_tree_init
0.01% git [kernel] [k] set_page_extent_mapped
0.01% git [kernel] [k] free_extent_state
0.01% git [kernel] [k] split_state
0.01% git [kernel] [k] spin_unlock
0.01% git [kernel] [k] memset_extent_buffer
0.01% git [kernel] [k] memcmp_extent_buffer
0.01% git [kernel] [k] extent_buffer_uptodate
0.01% git [kernel] [k] set_extent_buffer_uptodate
0.01% git [kernel] [k] __btrfs_map_block
0.01% git [kernel] [k] btrfs_map_bio
0.01% git [kernel] [k] bitmap_clear_bits
0.01% git [kernel] [k] btrfs_find_space_for_alloc
0.01% git [kernel] [k] btrfs_find_ref_cluster
0.01% git [kernel] [k] add_delayed_tree_ref
0.01% git [kernel] [k] cap_d_instantiate
0.01% git [kernel] [k] blk_rq_init
0.01% git [kernel] [k] radix_tree_lookup
0.01% git [kernel] [k] rb_insert_color
0.01% git [kernel] [k] rb_prev
0.01% git [kernel] [k] sha_transform
0.01% git [kernel] [k] strncpy_from_user
0.01% git [kernel] [k] copy_to_user
0.01% git [kernel] [k] tty_write
0.01% git [kernel] [k] __scsi_release_buffers
0.01% git [kernel] [k] scsi_io_completion
0.01% git [kernel] [k] ata_sff_interrupt
0.01% git [kernel] [k] mdio_ctrl_hw
0.01% git [kernel] [k] sock_alloc_send_pskb
0.01% git [kernel] [k] tcp_event_data_recv
0.01% git [kernel] [k] __tcp_select_window
0.01% git [kernel] [k] tcp_v4_send_check
0.01% git [kernel] [k] tcp_v4_rcv
0.01% git [kernel] [k] _cond_resched
0.01% git [kernel] [k] mutex_trylock
#
# (For a higher level overview, try: perf report --sort comm,dso)
#
-JimC
--
James Cloos <cl...@jhcloos.com> OpenPGP: 1024D/ED7DAEA6
