From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: Re: [RFC PATCH 1/2] vfs: tracepoints for buffer flag updates
Date: Thu, 12 Nov 2009 00:09:36 +0530
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References: <1257964260-14020-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>
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This patchset when enabled with stacktrace will give output like the below

              dd-1905  [003]    26.445155: set_buffer_uptodate: bh = df5c28c0 device = vda block = 34817 new state= 0x23
              dd-1905  [003]    26.445156: <stack trace>
 => set_buffer_uptodate
 => __block_commit_write
 => block_write_end
 => ext3_writeback_write_end
 => generic_file_buffered_write
 => __generic_file_aio_write
 => generic_file_aio_write
 => do_sync_write
              dd-1905  [003]    26.445168: clear_buffer_new: bh = df5c28c0 device = vda block = 34817 new state = 0x23
              dd-1905  [003]    26.445169: <stack trace>
 => clear_buffer_new
 => __block_commit_write
 => block_write_end
 => ext3_writeback_write_end
 => generic_file_buffered_write
 => __generic_file_aio_write
 => generic_file_aio_write
 => do_sync_write
              dd-1905  [003]    26.445182: set_buffer_revokevalid: bh = df406540 device = vda block = 32835 new state= 0x310029
              dd-1905  [003]    26.445183: <stack trace>
 => journal_cancel_revoke
 => do_get_write_access
 => journal_get_write_access
 => __ext3_journal_get_write_access
 => ext3_reserve_inode_write
 => ext3_mark_inode_dirty
 => ext3_dirty_inode
 => __mark_inode_dirty
              dd-1905  [003]    26.445197: clear_buffer_revoked: bh = df406540 device = vda block = 32835 new state = 0x310029
              dd-1905  [003]    26.445198: <stack trace>
 => journal_cancel_revoke
 => do_get_write_access
 => journal_get_write_access
 => __ext3_journal_get_write_access
 => ext3_reserve_inode_write
 => ext3_mark_inode_dirty
 => ext3_dirty_inode
 => __mark_inode_dirty


-aneesh