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Date:   Wed, 4 May 2022 12:56:25 +0530
From:   Jagdish Gediya <jvgediya@linux.ibm.com>
To:     Davidlohr Bueso <dave@stgolabs.net>
Cc:     linux-mm@kvack.org, mhocko@kernel.org, akpm@linux-foundation.org,
        rientjes@google.com, yosryahmed@google.com, hannes@cmpxchg.org,
        shakeelb@google.com, dave.hansen@linux.intel.com,
        tim.c.chen@linux.intel.com, roman.gushchin@linux.dev,
        gthelen@google.com, a.manzanares@samsung.com,
        heekwon.p@samsung.com, gim.jongmin@samsung.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/6] mm/vmscan: use node_is_toptier helper in node_reclaim
Message-ID: <YnIqofjeR+Q5FvgH@li-6e1fa1cc-351b-11b2-a85c-b897023bb5f3.ibm.com>
References: <20220416053902.68517-1-dave@stgolabs.net>
 <20220416053902.68517-3-dave@stgolabs.net>
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On Fri, Apr 15, 2022 at 10:38:58PM -0700, Davidlohr Bueso wrote:
> We have helpers for a reason.
> 
> Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
> ---
>  mm/vmscan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 1678802e03e7..cb583fcbf5bf 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -4750,7 +4750,7 @@ int node_reclaim(struct pglist_data *pgdat, gfp_t gfp_mask, unsigned int order)
>  	 * over remote processors and spread off node memory allocations
>  	 * as wide as possible.
>  	 */
> -	if (node_state(pgdat->node_id, N_CPU) && pgdat->node_id != numa_node_id())
> +	if (node_is_toptier(pgdat->node_id) && pgdat->node_id != numa_node_id())
Currently node_is_toptier returns all N_CPU node as toptier but N_CPU
node will not stay necessarily top tier as per discussions on below
thread.

https://lore.kernel.org/linux-mm/CAAPL-u9sVx94ACSuCVN8V0tKp+AMxiY89cro0japtyB=xNfNBw@mail.gmail.com/

node_is_toptier() definition can change based on the discussion in above
thread.
>  		return NODE_RECLAIM_NOSCAN;
>  
>  	if (test_and_set_bit(PGDAT_RECLAIM_LOCKED, &pgdat->flags))
> -- 
> 2.26.2
> 
>