Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Fri, 10 Sep 2021 13:43:55 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Feng Tang <feng.tang@intel.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        David Rientjes <rientjes@google.com>,
        Mel Gorman <mgorman@techsingularity.net>,
        Vlastimil Babka <vbabka@suse.cz>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/page_alloc: detect allocation forbidden by cpuset and
 bail out early
Message-ID: <YTtE+/w1I/6uj70f@dhcp22.suse.cz>
References: <1631003150-96935-1-git-send-email-feng.tang@intel.com>
 <YTcmcEUmtO++WeBk@dhcp22.suse.cz>
 <20210908015014.GA28091@shbuild999.sh.intel.com>
 <YThg8Mp42b194k0/@dhcp22.suse.cz>
 <20210910074400.GA18707@shbuild999.sh.intel.com>
 <YTsYxbMhGIunUPZr@dhcp22.suse.cz>
 <20210910092132.GA54659@shbuild999.sh.intel.com>
 <YTs01sPa5MojLGqO@dhcp22.suse.cz>
 <20210910112953.GB54659@shbuild999.sh.intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210910112953.GB54659@shbuild999.sh.intel.com>
Precedence: bulk

On Fri 10-09-21 19:29:53, Feng Tang wrote:
[...]
> > Sorry I didn't really get to read this previously. The implementation
> > works but I find it harder to read than really necessary. Why don't you
> > use first_zones_zonelist here as well?
> 
> The concern I had was which zonelist to use, local node or the first node
> of nodemask's node_zonelists[ZONELIST_FALLBACK],

I am not sure I see your concern. Either of the two should work just
fine because all nodes should be reachable from the zonelist. But why
don't you simply do the same kind of check as in the page allocator?
-- 
Michal Hocko
SUSE Labs