From: Andrew Morton <akpm@linux-foundation.org>
To: skseofh@gmail.com
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Mel Gorman <mgorman@techsingularity.net>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>
Subject: Re: [PATCH] mm/vmscan.c: no need to double-check if free pages are under high-watermark
Date: Wed, 5 Jan 2022 16:17:06 -0800 [thread overview]
Message-ID: <20220105161706.625b7b58d79eddaf38567568@linux-foundation.org> (raw)
In-Reply-To: <20220102033129.12913-1-skseofh@gmail.com>
On Sun, 2 Jan 2022 12:31:29 +0900 skseofh@gmail.com wrote:
> From: Daero Lee <skseofh@gmail.com>
>
> In kswapd_try_to_sleep function, to check whether kswapd can sleep,
> the prepare_kswapd_sleep function is called twice.
>
> If free pages are below high-watermark in the first call,
> the @remaining variable is not updated at 0 and the
> prepare_kswapd_sleep function is called for the second time.
>
> I think it is necessary to set the initial value of the
> @remaining to a non-zero value to prevent consecutive calls
> to the same function.
Seems right. Mel & Joonsoo, could you please check?
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -4331,7 +4331,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int highest_zoneidx)
> /*
> * Return the order kswapd stopped reclaiming at as
> * prepare_kswapd_sleep() takes it into account. If another caller
> - * entered the allocator slow path while kswapd was awake, order will
> + * entered the allqocator slow path while kswapd was awake, order will
whoops.
> * remain at the higher level.
> */
> return sc.order;
> @@ -4355,7 +4355,7 @@ static enum zone_type kswapd_highest_zoneidx(pg_data_t *pgdat,
> static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_order,
> unsigned int highest_zoneidx)
> {
> - long remaining = 0;
> + long remaining = ~0;
> DEFINE_WAIT(wait);
>
> if (freezing(current) || kthread_should_stop())
next prev parent reply other threads:[~2022-01-06 0:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-02 3:31 [PATCH] mm/vmscan.c: no need to double-check if free pages are under high-watermark skseofh
2022-01-06 0:17 ` Andrew Morton [this message]
2022-01-06 9:46 ` Mel Gorman
2022-01-06 12:03 ` DaeRo Lee
2022-01-06 12:57 ` Mel Gorman
2022-03-26 15:50 ` Wei Yang
2022-04-07 13:56 ` Mel Gorman
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