From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wu Fengguang Subject: Re: [PATCH 4/5] writeback: per task dirty rate limit Date: Wed, 10 Aug 2011 11:29:54 +0800 Message-ID: <20110810032954.GC24486@localhost> References: <20110806084447.388624428@intel.com> <20110806094527.002914580@intel.com> <20110809174621.GF6482@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "linux-fsdevel@vger.kernel.org" , Andrew Morton , Jan Kara , Christoph Hellwig , Dave Chinner , Greg Thelen , Minchan Kim , Andrea Righi , linux-mm , LKML To: Vivek Goyal Return-path: Content-Disposition: inline In-Reply-To: <20110809174621.GF6482@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Aug 10, 2011 at 01:46:21AM +0800, Vivek Goyal wrote: > On Sat, Aug 06, 2011 at 04:44:51PM +0800, Wu Fengguang wrote: > > [..] > > * balance_dirty_pages() must be called by processes which are generating dirty > > * data. It looks at the number of dirty pages in the machine and will force > > * the caller to perform writeback if the system is over `vm_dirty_ratio'. > > @@ -1008,6 +1005,9 @@ static void balance_dirty_pages(struct a > > if (clear_dirty_exceeded && bdi->dirty_exceeded) > > bdi->dirty_exceeded = 0; > > > > + current->nr_dirtied = 0; > > + current->nr_dirtied_pause = ratelimit_pages(nr_dirty, dirty_thresh); > > + > > if (writeback_in_progress(bdi)) > > return; > > > > @@ -1034,8 +1034,6 @@ void set_page_dirty_balance(struct page > > } > > } > > > > -static DEFINE_PER_CPU(unsigned long, bdp_ratelimits) = 0; > > - > > /** > > * balance_dirty_pages_ratelimited_nr - balance dirty memory state > > * @mapping: address_space which was dirtied > > @@ -1055,30 +1053,17 @@ void balance_dirty_pages_ratelimited_nr( > > { > > struct backing_dev_info *bdi = mapping->backing_dev_info; > > unsigned long ratelimit; > > - unsigned long *p; > > > > if (!bdi_cap_account_dirty(bdi)) > > return; > > > > - ratelimit = ratelimit_pages; > > - if (mapping->backing_dev_info->dirty_exceeded) > > + ratelimit = current->nr_dirtied_pause; > > + if (bdi->dirty_exceeded) > > ratelimit = 8; > > Should we make sure that ratelimit is more than 8? It could be that > ratelimit is 1 and we set it higher (just reverse of what we wanted?) Good catch! I actually just fixed it in that direction :) if (bdi->dirty_exceeded) - ratelimit = 8; + ratelimit = min(ratelimit, 32 >> (PAGE_SHIFT - 10)); Thanks, Fengguang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org