From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [PATCH] mm: vmpressure: fix scan window after SWAP_CLUSTER_MAX increase Date: Wed, 21 Oct 2015 15:38:52 -0400 Message-ID: <20151021193852.GA13511@cmpxchg.org> References: <1445278381-21033-1-git-send-email-hannes@cmpxchg.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <1445278381-21033-1-git-send-email-hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Andrew Morton Cc: Vladimir Davydov , linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org On Mon, Oct 19, 2015 at 02:13:01PM -0400, Johannes Weiner wrote: > mm-increase-swap_cluster_max-to-batch-tlb-flushes.patch changed > SWAP_CLUSTER_MAX from 32 pages to 256 pages, inadvertantly switching > the scan window for vmpressure detection from 2MB to 16MB. Revert. > > Signed-off-by: Johannes Weiner > --- > mm/vmpressure.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmpressure.c b/mm/vmpressure.c > index c5afd57..74f206b 100644 > --- a/mm/vmpressure.c > +++ b/mm/vmpressure.c > @@ -38,7 +38,7 @@ > * TODO: Make the window size depend on machine size, as we do for vmstat > * thresholds. Currently we set it to 512 pages (2MB for 4KB pages). > */ > -static const unsigned long vmpressure_win = SWAP_CLUSTER_MAX * 16; > +static const unsigned long vmpressure_win = SWAP_CLUSTER_MAX; Argh, Mel's patch sets SWAP_CLUSTER_MAX to 256, so this should be SWAP_CLUSTER_MAX * 2 to retain the 512 pages scan window. Andrew could you please update this fix in-place? Otherwise I'll resend a corrected version. Thanks, and sorry about that.