Re: [PATCH] block: fix splitting segments

Ming Lei
2020-01-10T02:58:16Z

On Thu, Jan 09, 2020 at 08:18:04AM -0700, Jens Axboe wrote:
> On 1/9/20 12:16 AM, Christoph Hellwig wrote:
> > On Thu, Jan 09, 2020 at 10:03:41AM +0800, Ming Lei wrote:
> >> It has been addressed in:
> >>
> >> https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/commit/?h=block-5.5&id=ecd255974caa45901d0b8fab03626e0a18fbc81a
> >
> > That is probably correct, but still highly suboptimal for most 32-bit
> > architectures where physical addresses are 32 bits wide. To fix that
> > the proper phys_addr_t type should be used.
>
> I'll swap it for phys_addr_t - we used to use dma_address_t or something
> like that, but I missed this type.

Guenter mentioned that 'page_to_phys(start_page) as well as offset are
sometimes 0'[1].

If that(zero page physical address) can happen when phys_addr_t is 32bit,
I guess phys_addr_t may not work too.

Guener, could you test the patch in link[2] again?

[1] https://lore.kernel.org/linux-block/20200108023822.GB28075@ming.t460p/T/#m5862216b960454fc41a85204defbb887983bfd75
[2] https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git/commit/?h=block-5.5&id=b6a89c4a9590663f80486662fe9a9c1f4cee31f4

Thanks,
Ming