Hi,
On Sun, Oct 27, 2013 at 07:51:15PM +0800, Ming Lei wrote:
> On Sat, 26 Oct 2013 15:36:17 +0100
> Will Deacon <will.deacon@xxxxxxx> wrote:
>
> > On Thu, Oct 24, 2013 at 09:07:30PM +0100, Aaro Koskinen wrote:
> >
> > > [ 36.477203] Backtrace:
> > > [ 36.535603] [<c009237c>] (page_mapping+0x0/0x50) from [<c0010dd8>] (flush_kernel_dcache_page+0x14/0x98)
> > > [ 36.661070] [<c0010dc4>] (flush_kernel_dcache_page+0x0/0x98) from [<c0172b60>] (sg_miter_stop+0xc8/0x10c)
> > > [ 36.792813] r4:df8a9a64 r3:00000003
> > > [ 36.857524] [<c0172a98>] (sg_miter_stop+0x0/0x10c) from [<c0172f20>] (sg_miter_next+0x14/0x13c)
> >
> > ... assumedly for scatter/gather DMA. How is your block driver allocating
> > its buffers? If you're using the DMA API, I can't see how this would happen.
>
> Lots of SCSI commands(inquiry, ...) pass kmalloc buffer to block layer,
> then the sg buffer copy helpers and flush_kernel_dcache_page() may see
> slab page.
>
> That has been here from commit b1adaf65ba03( [SCSI] block: add sg buffer copy
> helper functions).
On ARM v3.9 or older kernels do not trigger this BUG, at seems it only
started to appear with the following commit (bisected):
commit 1bc39742aab09248169ef9d3727c9def3528b3f3
Author: Simon Baatz <gmbnomis@xxxxxxxxx>
Date: Mon Jun 10 21:10:12 2013 +0100
ARM: 7755/1: handle user space mapped pages in flush_kernel_dcache_page
A.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>