Re: [PATCH v1 2/3] scsi: ufs: Optimize host lock on transfer requests send/compl paths

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2021-06-29 06:58, Bart Van Assche wrote:
On 5/24/21 1:36 AM, Can Guo wrote:
Current UFS IRQ handler is completely wrapped by host lock, and because
ufshcd_send_command() is also protected by host lock, when IRQ handler
fires, not only the CPU running the IRQ handler cannot send new requests, the rest CPUs can neither. Move the host lock wrapping the IRQ handler into specific branches, i.e., ufshcd_uic_cmd_compl(), ufshcd_check_errors(), ufshcd_tmc_handler() and ufshcd_transfer_req_compl(). Meanwhile, to further reduce occpuation of host lock in ufshcd_transfer_req_compl(), host lock is no longer required to call __ufshcd_transfer_req_compl(). As per test, the optimization can bring considerable gain to random read/write performance.

Hi Can,

Since this patch has been applied on the AOSP kernel we see 100%
reproducible lockups appearing on multiple test setups. Examples of call
traces:

blk_execute_rq()
__scsi_execute()
sd_sync_cache()
sd_suspend_common()
sd_suspend_system()
scsi_bus_suspend()
__device_suspend()

blk_execute_rq()
__scsi_execute()
ufshcd_clear_ua_wlun()
ufshcd_err_handling_unprepare()
ufshcd_err_handler()
process_one_work()

Reverting this patch and the next patch from this series solved the
lockups. Do you prefer to revert this patch or do you perhaps want us to
test a potential fix?


Hi Bart,

I am waiting for more infos/logs/dumps on Buganizor to look into it.
With above calltrace snippet, it is hard to figure out what is happening.
Besides, we've tested this series before go upstream and we didn't
see such problem.

Thanks,

Can Guo.

Thanks,

Bart.



[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [SCSI Target Devel]     [Linux SCSI Target Infrastructure]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Linux IIO]     [Samba]     [Device Mapper]

  Powered by Linux