From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: [PATCH 3/3] writeback: Add tracing to write_cache_pages Date: Wed, 7 Jul 2010 13:24:08 +1000 Message-ID: <1278473048-31564-4-git-send-email-david@fromorbit.com> References: <1278473048-31564-1-git-send-email-david@fromorbit.com> Cc: linux-fsdevel@vger.kernel.org To: axboe@kernel.dk Return-path: Received: from bld-mail18.adl2.internode.on.net ([150.101.137.103]:57215 "EHLO mail.internode.on.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753534Ab0GGDYZ (ORCPT ); Tue, 6 Jul 2010 23:24:25 -0400 In-Reply-To: <1278473048-31564-1-git-send-email-david@fromorbit.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Dave Chinner 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 Reviewed-by: Christoph Hellwig --- 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 0be26ac..bde92e0 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -148,6 +148,7 @@ 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 d556cd8..3d2111a 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -933,6 +933,7 @@ continue_unlock: if (!clear_page_dirty_for_io(page)) goto continue_unlock; + trace_wbc_writepage(wbc, mapping->backing_dev_info); ret = (*writepage)(page, wbc, data); if (unlikely(ret)) { if (ret == AOP_WRITEPAGE_ACTIVATE) { -- 1.7.1