From: Michal Hocko <mhocko@kernel.org>
To: Vinayak Menon <vinmenon@codeaurora.org>
Cc: akpm@linux-foundation.org, hannes@cmpxchg.org,
mgorman@techsingularity.net, vbabka@suse.cz, riel@redhat.com,
vdavydov.dev@gmail.com, anton.vorontsov@linaro.org,
minchan@kernel.org, shashim@codeaurora.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2 RESEND] mm: vmpressure: fix sending wrong events on underflow
Date: Mon, 6 Feb 2017 13:40:37 +0100 [thread overview]
Message-ID: <20170206124037.GA10298@dhcp22.suse.cz> (raw)
In-Reply-To: <1486383850-30444-2-git-send-email-vinmenon@codeaurora.org>
On Mon 06-02-17 17:54:10, Vinayak Menon wrote:
[...]
> diff --git a/mm/vmpressure.c b/mm/vmpressure.c
> index 149fdf6..3281b34 100644
> --- a/mm/vmpressure.c
> +++ b/mm/vmpressure.c
> @@ -112,8 +112,10 @@ static enum vmpressure_levels vmpressure_calc_level(unsigned long scanned,
> unsigned long reclaimed)
> {
> unsigned long scale = scanned + reclaimed;
> - unsigned long pressure;
> + unsigned long pressure = 0;
>
> + if (reclaimed >= scanned)
> + goto out;
This deserves a comment IMHO. Besides that, why shouldn't we normalize
the result already in vmpressure()? Please note that the tree == true
path will aggregate both scanned and reclaimed and that already skews
numbers.
--
Michal Hocko
SUSE Labs
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next prev parent reply other threads:[~2017-02-06 12:40 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-06 12:24 [PATCH 1/2 v4] mm: vmscan: do not pass reclaimed slab to vmpressure Vinayak Menon
2017-02-06 12:24 ` [PATCH 2/2 RESEND] mm: vmpressure: fix sending wrong events on underflow Vinayak Menon
2017-02-06 12:40 ` Michal Hocko [this message]
2017-02-06 13:09 ` vinayak menon
2017-02-06 13:24 ` Michal Hocko
2017-02-06 14:35 ` vinayak menon
2017-02-06 15:12 ` Michal Hocko
2017-02-07 11:17 ` vinayak menon
2017-02-07 12:09 ` Michal Hocko
2017-02-06 12:52 ` [PATCH 1/2 v4] mm: vmscan: do not pass reclaimed slab to vmpressure Michal Hocko
2017-02-06 15:10 ` vinayak menon
2017-02-07 8:10 ` Michal Hocko
2017-02-07 11:09 ` vinayak menon
2017-02-07 12:17 ` Michal Hocko
2017-02-07 13:16 ` vinayak menon
2017-02-07 14:52 ` Michal Hocko
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