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

[Can Guo]

Hi Stanley,

On 2021-06-03 10:54, Stanley Chu wrote:
> Hi Can,
>
> On Mon, 2021-05-24 at 01:36 -0700, 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.
> >
> > Cc: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
> > Co-developed-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> > Signed-off-by: Asutosh Das <asutoshd@xxxxxxxxxxxxxx>
> > Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
>
> According to my test, the performance indeed has impressive improvement
> with this series!

Thanks a lot for your time and review. :)

Regards,
Can Guo.

> Reviewed-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
>
>
>
>
> >  #endif
> >
> >  	bool req_abort_skip;
> > -	bool in_use;
> >  };
> >
> >  /**