RE: [SHDCI] Heavy (thousands) DMA leaks

Chen Bough
2015-07-31T06:56:48Z

Hi Jiri,

I will check this issue ASAP, thanks for report this!

Best Regards
Haibo Chen

> -----Original Message-----
> From: Jiri Slaby [mailto:jslaby@suse.cz]
> Sent: Thursday, July 30, 2015 5:32 PM
> To: Chen Haibo-B51421
> Cc: Ulf Hansson; linux-mmc@vger.kernel.org; Linux kernel mailing list
> Subject: [SHDCI] Heavy (thousands) DMA leaks
>
> Hi,
>
> after
> commit 348487cb28e66b032bae1b38424d81bf5b444408
> Author: Haibo Chen <haibo.chen@freescale.com>
> Date: Tue Dec 9 17:04:05 2014 +0800
>
> mmc: sdhci: use pipeline mmc requests to improve performance
>
> I see heavy DMA leaks which result in warnings of the dma api debug code:
> WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:509 add_dma_entry+0x138/0x150()
> DMA-API: exceeded 7 overlapping mappings of cacheline 0x000000000b20ec00
>
>
>
> And mainly this one upon sdhci module removal. It is over 4000 leaked
> mappings during one card transfer.
> mmc0: card e624 removed
> ------------[ cut here ]------------
> WARNING: CPU: 2 PID: 1263 at lib/dma-debug.c:974
> dma_debug_device_change+0x158/0x1c0()
> pci 0000:02:00.0: DMA-API: device driver has pending DMA allocations
> while released from device [count=4041] One of leaked entries details:
> [device address=0x00000000ddff0000]
> [size=65536 bytes] [mapped with DMA_FROM_DEVICE] [mapped as scather-
> gather] Modules linked in:
> CPU: 2 PID: 1263 Comm: bash Tainted: G W 4.2.0-rc4 #12
> Hardware name: LENOVO 23252SG/23252SG, BIOS G2ET33WW (1.13 ) 07/24/2012
> ffffffff81cc5e32 ffff8800d03c3b68 ffffffff81820938 0000000000000000
> ffff8800d03c3bb8 ffff8800d03c3ba8 ffffffff810b827a 0000000100260021
> ffff88030e500000 0000000000000fc9 ffff88030d95aeb8 ffff88030e4ddd68 Call
> Trace:
> [<ffffffff81820938>] dump_stack+0x4c/0x6e [<ffffffff810b827a>]
> warn_slowpath_common+0x8a/0xc0 [<ffffffff810b82f6>]
> warn_slowpath_fmt+0x46/0x50 [<ffffffff813248c8>]
> dma_debug_device_change+0x158/0x1c0
> [<ffffffff810d4e9d>] notifier_call_chain+0x4d/0x80 [<ffffffff810d51fd>]
> __blocking_notifier_call_chain+0x4d/0x70
> [<ffffffff810d5236>] blocking_notifier_call_chain+0x16/0x20
> [<ffffffff814db395>] __device_release_driver+0x105/0x130
> [<ffffffff814db3e3>] device_release_driver+0x23/0x30
> [<ffffffff814d95ca>] unbind_store+0xba/0xe0 [<ffffffff8123c638>] ?
> kernfs_fop_write+0xe8/0x170 [<ffffffff814d8ac4>]
> drv_attr_store+0x24/0x30 [<ffffffff8123ce4a>] sysfs_kf_write+0x3a/0x50
> [<ffffffff8123c670>] kernfs_fop_write+0x120/0x170 [<ffffffff811ce9e8>]
> __vfs_write+0x28/0xe0 [<ffffffff811d1209>] ? __sb_start_write+0x49/0xe0
> [<ffffffff810e3ba5>] ? local_clock+0x25/0x30 [<ffffffff811cf041>]
> vfs_write+0xa1/0x170 [<ffffffff810e43c4>] ? vtime_account_user+0x54/0x60
> [<ffffffff811cfce6>] SyS_write+0x46/0xa0 [<ffffffff81180f83>] ?
> context_tracking_user_exit+0x13/0x20
> [<ffffffff8182a017>] entry_SYSCALL_64_fastpath+0x12/0x6a
> ---[ end trace 398181ad32332b33 ]---
> Mapped at:
> [<ffffffff81324492>] debug_dma_map_sg+0x122/0x140 [<ffffffff81616dd3>]
> sdhci_pre_dma_transfer+0xc3/0x1b0 [<ffffffff81616f02>]
> sdhci_pre_req+0x42/0x70 [<ffffffff81601492>] mmc_pre_req+0x42/0x60
> [<ffffffff8160290e>] mmc_start_req+0x3e/0x400
>
> I already fixed one symptom -- memory corruption. Could you revisit the
> commit once again, as there is surely at least one more bug?
>
> thanks,
> --
> js
> suse labs