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From:   "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To:     Davidlohr Bueso <dave@stgolabs.net>, linux-mm@kvack.org,
        Wei Xu <weixugc@google.com>, Huang Ying <ying.huang@intel.com>
Cc:     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, dave@stgolabs.net,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/6] mm/vmscan: use node_is_toptier helper in node_reclaim
In-Reply-To: <20220416053902.68517-3-dave@stgolabs.net>
References: <20220416053902.68517-1-dave@stgolabs.net>
 <20220416053902.68517-3-dave@stgolabs.net>
Date:   Tue, 31 May 2022 17:20:42 +0530
Message-ID: <87h755dip9.fsf@linux.ibm.com>
MIME-Version: 1.0
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Davidlohr Bueso <dave@stgolabs.net> writes:

> 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())
>  		return NODE_RECLAIM_NOSCAN;
>  
>  	if (test_and_set_bit(PGDAT_RECLAIM_LOCKED, &pgdat->flags))


Are we really looking at the top tier in a tiered memory hierarchy here?
The comment seems to suggest we are looking at local NUMA node?


-aneesh