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Subject: Re: [PATCH v3] swiotlb: Make SWIOTLB_NO_FORCE perform no allocation
To:     Christoph Hellwig <hch@lst.de>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc:     linux-kernel@vger.kernel.org,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Robin Murphy <robin.murphy@arm.com>,
        "open list:SWIOTLB SUBSYSTEM" <iommu@lists.linux-foundation.org>
References: <20210321033740.312500-1-f.fainelli@gmail.com>
 <20210323015350.399493-1-f.fainelli@gmail.com> <20210324084250.GA4474@lst.de>
From:   Florian Fainelli <f.fainelli@gmail.com>
Message-ID: <2ad22811-24e8-0776-3e55-ea2a4ac55f55@gmail.com>
Date:   Thu, 8 Apr 2021 20:13:07 -0700
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On 3/24/2021 1:42 AM, Christoph Hellwig wrote:
> On Mon, Mar 22, 2021 at 06:53:49PM -0700, Florian Fainelli wrote:
>> When SWIOTLB_NO_FORCE is used, there should really be no allocations of
>> default_nslabs to occur since we are not going to use those slabs. If a
>> platform was somehow setting swiotlb_no_force and a later call to
>> swiotlb_init() was to be made we would still be proceeding with
>> allocating the default SWIOTLB size (64MB), whereas if swiotlb=noforce
>> was set on the kernel command line we would have only allocated 2KB.
>>
>> This would be inconsistent and the point of initializing default_nslabs
>> to 1, was intended to allocate the minimum amount of memory possible, so
>> simply remove that minimal allocation period.
>>
>> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> 
> Looks good,
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> 

Thanks! Konrad, can you apply this patch to your for-linus-5.13 branch
if you are also happy with it?
-- 
Florian