From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: [PATCH 3/6] writeback: Add tracing to write_cache_pages Date: Fri, 4 Jun 2010 09:55:25 +1000 Message-ID: <1275609328-12514-4-git-send-email-david@fromorbit.com> References: <1275609328-12514-1-git-send-email-david@fromorbit.com> Cc: linux-kernel@vger.kernel.org, xfs@oss.sgi.com, akpm@linux-foundation.org To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1275609328-12514-1-git-send-email-david@fromorbit.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org 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 --- 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