Re: [patch] voluntary-preempt-2.6.8-rc4-O7

Lee Revell
2004-08-13T21:34:54Z

On Fri, 2004-08-13 at 06:48, Ingo Molnar wrote:

> http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.8-rc4-O7
>

Here is the trace resulting from the apt-get filemap_sync() issue:

preemption latency trace v1.0
-----------------------------
latency: 3656 us, entries: 4000 (8605)
process: apt-get/21227, uid: 0
nice: 0, policy: 0, rt_priority: 0
=======>
0.000ms (+0.000ms): filemap_sync_pte_range (filemap_sync)
0.000ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.002ms (+0.001ms): set_page_dirty (filemap_sync_pte)
0.002ms (+0.000ms): __set_page_dirty_buffers (set_page_dirty)
0.004ms (+0.001ms): radix_tree_tag_set (__set_page_dirty_buffers)
0.006ms (+0.001ms): __mark_inode_dirty (__set_page_dirty_buffers)
0.008ms (+0.001ms): filemap_sync_pte (filemap_sync_pte_range)
0.009ms (+0.000ms): set_page_dirty (filemap_sync_pte)
0.009ms (+0.000ms): __set_page_dirty_buffers (set_page_dirty)
0.010ms (+0.000ms): radix_tree_tag_set (__set_page_dirty_buffers)
0.011ms (+0.000ms): __mark_inode_dirty (__set_page_dirty_buffers)
0.011ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.012ms (+0.000ms): set_page_dirty (filemap_sync_pte)
0.012ms (+0.000ms): __set_page_dirty_buffers (set_page_dirty)
0.013ms (+0.000ms): radix_tree_tag_set (__set_page_dirty_buffers)
0.013ms (+0.000ms): __mark_inode_dirty (__set_page_dirty_buffers)
0.014ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.014ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.015ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.016ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.016ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.017ms (+0.000ms): set_page_dirty (filemap_sync_pte)
0.017ms (+0.000ms): __set_page_dirty_buffers (set_page_dirty)
0.018ms (+0.000ms): radix_tree_tag_set (__set_page_dirty_buffers)
0.019ms (+0.000ms): __mark_inode_dirty (__set_page_dirty_buffers)
0.019ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.019ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.020ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.020ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.021ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
0.022ms (+0.000ms): set_page_dirty (filemap_sync_pte)
0.022ms (+0.000ms): __set_page_dirty_buffers (set_page_dirty)
0.023ms (+0.000ms): radix_tree_tag_set (__set_page_dirty_buffers)
0.023ms (+0.000ms): __mark_inode_dirty (__set_page_dirty_buffers)

[ zillons of these deleted ]

1.960ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
1.960ms (+0.000ms): set_page_dirty (filemap_sync_pte)
1.961ms (+0.000ms): __set_page_dirty_buffers (set_page_dirty)
1.961ms (+0.000ms): preempt_schedule (__set_page_dirty_buffers)
1.961ms (+0.000ms): radix_tree_tag_set (__set_page_dirty_buffers)
1.962ms (+0.000ms): preempt_schedule (__set_page_dirty_buffers)
1.962ms (+0.000ms): __mark_inode_dirty (__set_page_dirty_buffers)
1.963ms (+0.000ms): filemap_sync_pte (filemap_sync_pte_range)
1.964ms (+0.000ms): set_page_dirty (filemap_sync_pte)
1.964ms (+0.000ms): __set_page_dirty_buffers (set_page_dirty)
1.964ms (+0.000ms): preempt_schedule (__set_page_dirty_buffers)
1.965ms (+0.000ms): radix_tree_tag_set (__set_page_dirty_buffers)

Lee