Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Thu, 11 Aug 2022 10:25:16 +0200
From:   Michal Hocko <mhocko@suse.com>
To:     Christoph Hellwig <hch@lst.de>
Cc:     Baoquan He <bhe@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        John Donnelly <john.p.donnelly@oracle.com>,
        David Hildenbrand <david@redhat.com>, linux-mm@kvack.org,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] dma/pool: do not complain if DMA pool is not allocated
Message-ID: <YvS87E6Vx/3PvMPr@dhcp22.suse.cz>
References: <YuqNToCACD8kKBG+@MiWiFi-R3L-srv>
 <YuqOrJKcgfamdXkk@dhcp22.suse.cz>
 <YuqU87SDwP0zg+c7@MiWiFi-R3L-srv>
 <YuqX0OAItlMDfRUV@dhcp22.suse.cz>
 <YuunCO2lsLDWTGw+@MiWiFi-R3L-srv>
 <Yuu1EyC95XL98XNI@dhcp22.suse.cz>
 <Yu0OWLbzLxCkSGVJ@MiWiFi-R3L-srv>
 <Yu1VTAxd9/jP/iEk@dhcp22.suse.cz>
 <YvJ/V2bor9Q3P6ov@dhcp22.suse.cz>
 <20220811073840.GE13886@lst.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220811073840.GE13886@lst.de>
Precedence: bulk

On Thu 11-08-22 09:38:40, Christoph Hellwig wrote:
> On Tue, Aug 09, 2022 at 05:37:59PM +0200, Michal Hocko wrote:
> > Here we go again.
> 
> And just as last time I think this is the wrong thing to do.
> IFF we actually need the pool and we can't allocate it we want this
> warning.
> 
> But order-10 seems very larger for the 31-bit ISA DMA zone, so we might
> want to look into calculating the pool size based on the zone size
> instead.

No objection for a better size tuning from my side. I find it 
I suspect you will need __GFP_NOWARN to be used for downsizing the
request size for all attempts anyway.

-- 
Michal Hocko
SUSE Labs