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Date:   Thu, 10 Dec 2020 09:18:02 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Randy Dunlap <rdunlap@infradead.org>
Cc:     Christoph Hellwig <hch@infradead.org>,
        linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
        Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
        Ley Foon Tan <ley.foon.tan@intel.com>,
        Mark Salter <msalter@redhat.com>,
        Aurelien Jacquiot <jacquiot.aurelien@gmail.com>,
        linux-c6x-dev@linux-c6x.org
Subject: Re: [PATCH] block: blk-iocost: fix build for ARCH with missing
 local64.h files
Message-ID: <20201210081802.GS3040@hirez.programming.kicks-ass.net>
References: <20201209204657.6676-1-rdunlap@infradead.org>
 <20201210060742.GA19263@infradead.org>
 <04828b4e-8791-6f3e-8984-9de06f40c85a@infradead.org>
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On Wed, Dec 09, 2020 at 10:16:20PM -0800, Randy Dunlap wrote:
> On 12/9/20 10:07 PM, Christoph Hellwig wrote:
> > On Wed, Dec 09, 2020 at 12:46:57PM -0800, Randy Dunlap wrote:
> >> When building block/blk-iocost.c on arch/x6x/ or arch/nios2/, the
> >> build fails due to missing the <asm/local64.h> file.
> > 
> > Please mark it mandatory-y if the asm-generic version is suitable
> > for everyone and random pieces of kernel code are supposed to include
> > it.
> 
> include/asm-generic/local64.h has comments about some $arch could do
> its things better/faster instead of using asm-generic, but no $arch has
> done that since 2010 when it was added.

Yeah, it's only 32bit archs, and of those I'm only sure i386 could do it
better, very maybe arm-v7. But nobody cares enough to make it happen.

All the 64bit archs are already good, because local_t is long and
local64_t defaults to local_t.