Hi,

 I'm using btrfs as rootfs on my Fedora 12 (rawhide) test system.
Every yum activity is very slow, like 15 minutes for installation of 11
packages 25MB in size. Kernel is 2.6.31.1-48.fc12.x86_64, btrfs-progs-0.19-7.fc12.x86_64.
Hardware is pentium 4 3.0 GHz (Hyperthreading, 64 bit), with single IDE disk 
on Intel ICH controller.

/dev/sda2 on / type btrfs (rw)

/dev/sda2              19G  6,7G   13G  36% /

  Attached is output from vmstat 1 during yum transaction. I also
have 200MB of "perf record" output, which I can drill down. First screen
of profile is below:

# Samples: 9024736
#
# Overhead          Command                                         Shared Object  Symbol
# ........  ...............  ....................................................  ......
#
    15.44%  perf.2.6.31-33.  [kernel]                                              [k] kmem_cache_open
     9.74%  perf.2.6.31-33.  [kernel]                                              [k] print_lock_contention_bug
     6.34%  perf.2.6.31-33.  [kernel]                                              [k] free_kmem_cache_cpus
     4.49%  perf.2.6.31-33.  [kernel]                                              [k] is_module_text_address
     4.01%  perf.2.6.31-33.  [kernel]                                              [k] lock_set_class
     3.45%  yum-complete-tr  [kernel]                                              [k] print_lock_contention_bug
     2.50%  perf.2.6.31-33.  [kernel]                                              [k] _spin_lock
     2.48%  yum-complete-tr  [kernel]                                              [k] kmem_cache_open
     2.47%  perf.2.6.31-33.  [kernel]                                              [k] zlib_tr_flush_block      [zlib_deflate]
     1.65%  yum-complete-tr  [kernel]                                              [k] lock_set_class
     1.62%  perf.2.6.31-33.  [kernel]                                              [k] schedule_hrtimeout_range
     1.53%  perf.2.6.31-33.  [kernel]                                              [k] sysfs_slab_add
     1.50%  yum-complete-tr  [kernel]                                              [k] zlib_tr_flush_block      [zlib_deflate]
     1.46%  yum-complete-tr  [kernel]                                              [k] free_kmem_cache_cpus
     1.40%  yum-complete-tr  [kernel]                                              [k] _spin_lock
     1.34%  perf.2.6.31-33.  [kernel]                                              [k] __mutex_lock_common
     1.27%  perf.2.6.31-33.  [kernel]                                              [k] btrfs_getxattr   [btrfs]
     1.06%  perf.2.6.31-33.  [kernel]                                              [k] lock_contended
     0.78%  perf.2.6.31-33.  [kernel]                                              [k] _raw_read_unlock
     0.75%  perf.2.6.31-33.  [kernel]                                              [k] btrfs_listxattr  [btrfs]
     0.74%  perf.2.6.31-33.  [kernel]                                              [k] run_scheduled_bios       [btrfs]
     0.62%  perf.2.6.31-33.  [kernel]                                              [k] lockdep_count_backward_deps
     0.61%  perf.2.6.31-33.  [kernel]                                              [k] show_slab_objects
     0.58%  yum-complete-tr  [kernel]                                              [k] sysfs_slab_add
     0.48%  yum-complete-tr  /usr/lib64/libpython2.6.so.1.0                        [.] 0x0000000005dab0
     0.46%  yum-complete-tr  [kernel]                                              [k] btrfs_listxattr  [btrfs]
     0.45%  yum-complete-tr  /usr/lib64/librpm.so.0.0.0                            [.] 0x0000000004877f
     0.44%  perf.2.6.31-33.  [kernel]                                              [k] idr_for_each
     0.44%  perf.2.6.31-33.  [kernel]                                              [k] clear_lock_stats
     0.44%  yum-complete-tr  [kernel]                                              [k] lock_contended
     0.43%  perf.2.6.31-33.  [kernel]                                              [k] btrfs_iget       [btrfs]
     0.41%  yum-complete-tr  [kernel]                                              [k] is_module_text_address
     0.37%  yum-complete-tr  /usr/lib64/libpython2.6.so.1.0                        [.] PyEval_EvalFrameEx
     0.36%  yum-complete-tr  [kernel]                                              [k] run_scheduled_bios       [btrfs]
     0.36%  yum-complete-tr  [kernel]                                              [k] show_slab_objects
     0.33%  perf.2.6.31-33.  [kernel]                                              [k] lock_acquire
     0.33%  perf.2.6.31-33.  [kernel]                                              [k] __module_text_address
     0.29%  yum-complete-tr  [kernel]                                              [k] btrfs_getxattr   [btrfs]
     0.28%         ldconfig  [kernel]                                              [k] free_kmem_cache_cpus
     0.27%  perf.2.6.31-33.  [kernel]                                              [k] btrfs_set_device_sector_size     [btrfs]
     0.26%  yum-complete-tr  [kernel]                                              [k] _raw_read_unlock
     0.25%  perf.2.6.31-33.  [kernel]                                              [k] _spin_lock_bh
     0.25%  yum-complete-tr  [kernel]                                              [k] btrfs_drop_extents       [btrfs]
     0.23%  perf.2.6.31-33.  [kernel]                                              [k] btrfs_comp_cpu_keys      [btrfs]
     0.23%  yum-complete-tr  /lib64/libc-2.10.90.so                                [.] __GI_memcpy



-- 
Tomasz Torcz                                                       72->|   80->|
xmpp: zdzichubg@chrome.pl                                          72->|   80->|