Subject: [3.15-rc1] a huge number of warnings produced by xhci &

From: [email-masked] (Grygorii Strashko)
Date: Tue, 15 Apr 2014 13:00:19 +0300

On 04/14/2014 08:12 PM, Christoph Lameter wrote:
> n Mon, 14 Apr 2014, Grygorii Strashko wrote:
>
>> Hi All,
>>
>> I'm observing a huge number of warnings produced during the boot of my Keystone 2 board
>> when USB is enabled.
>>
>> [    2.496460] BUG: using __this_cpu_read() in preemptible [00000000] code: khubd/202
>> [    2.504030] caller is __mod_zone_page_state+0x20/0xc8
>> [    2.509094] CPU: 1 PID: 202 Comm: khubd Not tainted 3.15.0-rc1-00015-ge521fa3-dirty #55
>> [    2.517122] [<c0013788>] (unwind_backtrace) from [<c001129c>] (show_stack+0x10/0x14)
>> [    2.524854] [<c001129c>] (show_stack) from [<c049f800>] (dump_stack+0x68/0xb8)
>> [    2.532086] [<c049f800>] (dump_stack) from [<c02731c0>] (check_preemption_disabled+0xe8/0x10c)
>> [    2.540708] [<c02731c0>] (check_preemption_disabled) from [<c00bc944>] (__mod_zone_page_state+0x20/0xc8)
>> [    2.550187] [<c00bc944>] (__mod_zone_page_state) from [<c00b50c8>] (reclaim_clean_pages_from_list+0x16c/0x178)
>> [    2.560193] [<c00b50c8>] (reclaim_clean_pages_from_list) from [<c00ac8f0>] (alloc_contig_range+0x10c/0x2d0)
>> [    2.569932] [<c00ac8f0>] (alloc_contig_range) from [<c02b0e58>] (dma_alloc_from_contiguous+0x70/0x118)
>> [    2.579241] [<c02b0e58>] (dma_alloc_from_contiguous) from [<c0017d24>] (__alloc_from_contiguous+0x34/0x160)
>> [    2.588974] [<c0017d24>] (__alloc_from_contiguous) from [<c0018760>] (__dma_alloc+0x18c/0x294)
>> [    2.597582] [<c0018760>] (__dma_alloc) from [<c00189f0>] (arm_dma_alloc+0xac/0xd8)
>> [    2.605140] [<c00189f0>] (arm_dma_alloc) from [<c00d84a8>] (dma_pool_alloc+0xc8/0x1b8)
>> [    2.613067] [<c00d84a8>] (dma_pool_alloc) from [<c0317120>] (xhci_alloc_container_ctx+0x70/0xe0)
>> [    2.621851] [<c0317120>] (xhci_alloc_container_ctx) from [<c03194e8>] (xhci_alloc_virt_device+0x98/0x220)
>> [    2.631418] [<c03194e8>] (xhci_alloc_virt_device) from [<c0315d28>] (xhci_alloc_dev+0x158/0x1f0)
>> [    2.640207] [<c0315d28>] (xhci_alloc_dev) from [<c02f6310>] (usb_alloc_dev+0x1d4/0x27c)
>> [    2.648217] [<c02f6310>] (usb_alloc_dev) from [<c02fb204>] (hub_thread+0x670/0x1204)
>> [    2.655943] [<c02fb204>] (hub_thread) from [<c003d8d8>] (kthread+0xcc/0xe8)
>> [    2.662906] [<c003d8d8>] (kthread) from [<c000e2f8>] (ret_from_fork+0x14/0x3c)
>>
>> Anyone else sees the same thing?
>
> Either disable interrupts or use mod_zone_page_state instead.
>
> This should fix it:
>
>
>
>
> Subject: vmscan: reclaim_clean_pages_from_list must use mod_zone_page_state
>
> Seems to be called with preemption enabled. Therefore it must use
> mod_zone_page_state instead.
>
> Signed-off-by: Christoph Lameter <[email-masked]>

This patch fixes issue for me on Keystone 2, thanks.
Tested-by: Grygorii Strashko <[email-masked]>

>
> Index: linux/mm/vmscan.c
> ===================================================================
> --- linux.orig/mm/vmscan.c	2014-04-09 11:35:43.917930976 -0500
> +++ linux/mm/vmscan.c	2014-04-14 12:09:48.070745938 -0500
> @@ -1158,7 +1158,7 @@ unsigned long reclaim_clean_pages_from_l
>   			TTU_UNMAP|TTU_IGNORE_ACCESS,
>   			&dummy1, &dummy2, &dummy3, &dummy4, &dummy5, true);
>   	list_splice(&clean_pages, page_list);
> -	__mod_zone_page_state(zone, NR_ISOLATED_FILE, -ret);
> +	mod_zone_page_state(zone, NR_ISOLATED_FILE, -ret);
>   	return ret;
>   }
>