From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Ryabinin Subject: Re: [PATCH v2 3/4] mm/vmscan: Don't change pgdat state on base of a single LRU list state. Date: Fri, 6 Apr 2018 20:25:10 +0300 Message-ID: <312906df-80c4-aaaf-3d0f-caaeeceb9f39@virtuozzo.com> References: <20180323152029.11084-1-aryabinin@virtuozzo.com> <20180323152029.11084-4-aryabinin@virtuozzo.com> <20180406162835.GD20806@cmpxchg.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=virtuozzo.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=5R3zq4IZ6J0W6STusX0nl8ua2fLRXkNcuFoH4SLlnSE=; b=SzBpXbkaN5+71ckFijNN7pNY6hzP5ocjghpmkoPAEaln7L6L8piYU5yBQbW637EhlTZUbSAZ3cwo9qDauEbC4GLsTn/JvGBH162ozkRBt62VHuDn0v1NZzfqCtfNwrFXuZkd+MIHU8Yp8O8J5Dw9PKfzHBOLvztNEJuvmSCsD7I= In-Reply-To: <20180406162835.GD20806@cmpxchg.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Johannes Weiner Cc: Andrew Morton , Mel Gorman , Tejun Heo , Michal Hocko , Shakeel Butt , Steven Rostedt , linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org On 04/06/2018 07:28 PM, Johannes Weiner wrote: > > This isn't quite equivalent to what we have right now. > > Yes, nr_dirty, nr_unqueued_dirty and nr_congested apply to file pages > only. That part is about waking the flushers and avoiding writing > files in 4k chunks from reclaim context. So those numbers do need to > be compared against scanned *file* pages. > > But nr_writeback and nr_immediate is about throttling reclaim when we > hit too many pages under writeout, and that applies to both file and > anonymous/swap pages. We do want to throttle on swapout, too. > > So nr_writeback needs to check against all nr_taken, not just file. > Agreed, the fix bellow. It causes conflict in the next 4/4 patch, so I'll just send v3 with all fixes folded. --- mm/vmscan.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 4d848b8df01f..c45497475e84 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -124,6 +124,7 @@ struct scan_control { unsigned int writeback; unsigned int immediate; unsigned int file_taken; + unsigned int taken; } nr; }; @@ -1771,6 +1772,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct lruvec *lruvec, sc->nr.unqueued_dirty += stat.nr_unqueued_dirty; sc->nr.writeback += stat.nr_writeback; sc->nr.immediate += stat.nr_immediate; + sc->nr.taken += nr_taken; if (file) sc->nr.file_taken += nr_taken; @@ -2553,7 +2555,7 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) * number of pages under pages flagged for immediate reclaim and * stall if any are encountered in the nr_immediate check below. */ - if (sc->nr.writeback && sc->nr.writeback == sc->nr.file_taken) + if (sc->nr.writeback && sc->nr.writeback == sc->nr.taken) set_bit(PGDAT_WRITEBACK, &pgdat->flags); /* -- 2.16.1