From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wu Fengguang <fengguang.wu@intel.com>
Subject: Re: [PATCH] writeback: trace global_dirty_state
Date: Tue, 14 Jun 2011 21:46:55 +0800
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Cc: Andrew Morton <akpm@linux-foundation.org>,
	Dave Chinner <david@fromorbit.com>,
	Christoph Hellwig <hch@infradead.org>,
	Linux Memory Management List <linux-mm@kvack.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
To: Jan Kara <jack@suse.cz>
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On Mon, Jun 13, 2011 at 10:33:56PM +0800, Jan Kara wrote:
> On Fri 10-06-11 22:48:05, Wu Fengguang wrote:
> > [It seems beneficial to queue this simple trace event for
> >  next/upstream after the review?]
> > 
> > Add trace event balance_dirty_state for showing the global dirty page
> > counts and thresholds at each global_dirty_limits() invocation.  This
> > will cover the callers throttle_vm_writeout(), over_bground_thresh()
> > and each balance_dirty_pages() loop.
>   OK, this might be useful. But shouldn't we also add similar trace point
> for bdi limits? Otherwise the information is of limited use...

Good point. The bdi limits will be exported in another
balance_dirty_pages trace point.

Thanks,
Fengguang