Messages in this thread Patch in this message | | | From | Dave Chinner <> | Subject | [PATCH 3/6] writeback: Add tracing to write_cache_pages | Date | Fri, 4 Jun 2010 09:55:25 +1000 |
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Add a trace event to the ->writepage loop in write_cache_pages to give visibility into how the ->writepage call is changing variables within the writeback control structure. Of most interest is how wbc->nr_to_write changes from call to call, especially with filesystems that write multiple pages in ->writepage.
Signed-off-by: Dave Chinner <dchinner@redhat.com> --- include/trace/events/writeback.h | 1 + mm/page-writeback.c | 1 + 2 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index 72c1a12..5dda40e 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -244,6 +244,7 @@ DEFINE_WBC_EVENT(wbc_writeback_wait); DEFINE_WBC_EVENT(wbc_balance_dirty_start); DEFINE_WBC_EVENT(wbc_balance_dirty_written); DEFINE_WBC_EVENT(wbc_balance_dirty_wait); +DEFINE_WBC_EVENT(wbc_writepage); #endif /* _TRACE_WRITEBACK_H */ diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 68eb727..caaf954 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -921,6 +921,7 @@ continue_unlock: if (!clear_page_dirty_for_io(page)) goto continue_unlock; + trace_wbc_writepage(wbc); ret = (*writepage)(page, wbc, data); if (unlikely(ret)) { if (ret == AOP_WRITEPAGE_ACTIVATE) { -- 1.7.1
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