RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-24 Thread Finn Thain
On Wed, 24 Feb 2021, Song Bao Hua (Barry Song) wrote: > > Realtime requirement is definitely a true requirement on ARM Linux. > > I once talked/worked with some guys who were using ARM for realtime > system. > The feasible approaches include: > 1. Dual OS(RTOS + Linux): e.g. QNX+Linux XENOMAI+

Re: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-24 Thread Xiaofei Tan
Hi Geert, On 2021/2/24 17:41, Geert Uytterhoeven wrote: Hi Xiaofei, On Sun, Feb 7, 2021 at 12:46 PM Xiaofei Tan wrote: Replace spin_lock_irqsave with spin_lock in hard IRQ of SCSI drivers. There are no function changes, but may speed up if interrupt happen too often. I'll bite: how much doe

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-24 Thread Song Bao Hua (Barry Song)
> -Original Message- > From: Finn Thain [mailto:fth...@telegraphics.com.au] > Sent: Wednesday, February 24, 2021 6:21 PM > To: Song Bao Hua (Barry Song) > Cc: tanxiaofei ; j...@linux.ibm.com; > martin.peter...@oracle.com; linux-s...@vger.kernel.org; > linux-kernel@vger.kernel.org; linux.

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-23 Thread Finn Thain
On Tue, 23 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > Regarding m68k, your analysis overlooks the timing issue. E.g. patch > > 11/32 could be a problem because removing the irqsave would allow PDMA > > transfers to be interrupted. Aside from the timing issues, I agree > > with your ana

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-22 Thread Song Bao Hua (Barry Song)
ger.kernel.org; linux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > On Mon, 22 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > On Thu, 18 Feb 2021, Xiaof

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-22 Thread Finn Thain
On Mon, 22 Feb 2021, Song Bao Hua (Barry Song) wrote: > > On Thu, 18 Feb 2021, Xiaofei Tan wrote: > > > > > On 2021/2/9 13:06, Finn Thain wrote: > > > > On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > > > > > On Sun, 7 Feb 2021, Xiaofei Tan wrote: > > > > > > > > > > > > > Replac

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-21 Thread Song Bao Hua (Barry Song)
x-kernel@vger.kernel.org; linux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: Re: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > On Thu, 18 Feb 2021, Xiaofei Tan wrote: > > > On 2021/2/9 13:06, Finn Thain wrote:

Re: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-19 Thread Finn Thain
On Thu, 18 Feb 2021, Xiaofei Tan wrote: > On 2021/2/9 13:06, Finn Thain wrote: > > On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > On Sun, 7 Feb 2021, Xiaofei Tan wrote: > > > > > > > > > Replace spin_lock_irqsave with spin_lock in hard IRQ of SCSI > > > > > drivers. There are

Re: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-18 Thread Xiaofei Tan
Hi Finn, On 2021/2/9 13:06, Finn Thain wrote: On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: -Original Message- From: Finn Thain [mailto:fth...@telegraphics.com.au] Sent: Monday, February 8, 2021 8:57 PM To: tanxiaofei Cc: j...@linux.ibm.com; martin.peter...@oracle.com; linux-s.

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-11 Thread Song Bao Hua (Barry Song)
ger.kernel.org; linux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > On Thu, 11 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > On Wed, 10 Feb 2021, Song Bao

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-11 Thread Finn Thain
On Thu, 11 Feb 2021, Song Bao Hua (Barry Song) wrote: > > On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > > > > TBH, that is why m68k is so confusing. irqs_disabled() on m68k > > > > > should just reflect the sta

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-10 Thread Song Bao Hua (Barry Song)
ger.kernel.org; linux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > On Wed, 10 Feb 2021, Song Bao

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-10 Thread Finn Thain
On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > > > > > There is no warning from m68k builds. That's because > > > > > > arch_irqs_disabled() returns true

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-10 Thread Song Bao Hua (Barry Song)
ger.kernel.org; linux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > O

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-10 Thread Finn Thain
On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > > > > > There is no warning from m68k builds. That's because > > > > arch_irqs_disabled() returns true when the IPL is non-zero. > > > > > > So for m68k, the case is > > >

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-10 Thread Song Bao Hua (Barry Song)
ger.kernel.org; linux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > > On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > &g

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-10 Thread Finn Thain
On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > > sonic_interrupt() uses an irq lock within an interrupt handler > > > > > to avoid issues relating to this. This kind of locking may be > > > > > needed in the drivers y

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-09 Thread Song Bao Hua (Barry Song)
> -Original Message- > From: Finn Thain [mailto:fth...@telegraphics.com.au] > Sent: Wednesday, February 10, 2021 5:16 PM > To: Song Bao Hua (Barry Song) > Cc: tanxiaofei ; j...@linux.ibm.com; > martin.peter...@oracle.com; linux-s...@vger.kernel.org; > linux-kernel@vger.kernel.org; linux.

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-09 Thread Finn Thain
On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > sonic_interrupt() uses an irq lock within an interrupt handler to > > > avoid issues relating to this. This kind of locking may be needed in > > > the drivers you are trying to patch. Or it might not. Apparently, > > > no-one has looked

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-09 Thread Finn Thain
On Wed, 10 Feb 2021, Song Bao Hua (Barry Song) wrote: > > On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > > > > > On Sun, 7 Feb 2021, Xiaofei Tan wrote: > > > > > > > > > > > > > Replace spin_lock_irqsave with spin_

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-09 Thread Song Bao Hua (Barry Song)
ernel@vger.kernel.org; linux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > On Tue, 9 Feb 2021, Song Ba

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-09 Thread Finn Thain
On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > > > On Sun, 7 Feb 2021, Xiaofei Tan wrote: > > > > > > > > > Replace spin_lock_irqsave with spin_lock in hard IRQ of SCSI > > > > > drivers. There are no function changes, but ma

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-08 Thread Song Bao Hua (Barry Song)
nux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > > > > -Original Message- > > From: Finn Thain [mailto:fth...@telegraphics.com.au] > > Sent: Tuesd

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-08 Thread Song Bao Hua (Barry Song)
ger.kernel.org; linux...@openeuler.org; > linux-m...@vger.kernel.org > Subject: RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage > optimization > for SCSI drivers > > On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > > > -Origi

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-08 Thread Finn Thain
On Tue, 9 Feb 2021, Song Bao Hua (Barry Song) wrote: > > -Original Message- > > From: Finn Thain [mailto:fth...@telegraphics.com.au] > > Sent: Monday, February 8, 2021 8:57 PM > > To: tanxiaofei > > Cc: j...@linux.ibm.com; martin.peter...@oracle.com; > > linux-s...@vger.kernel.org; linux-

RE: [Linuxarm] Re: [PATCH for-next 00/32] spin lock usage optimization for SCSI drivers

2021-02-08 Thread Song Bao Hua (Barry Song)
> -Original Message- > From: Finn Thain [mailto:fth...@telegraphics.com.au] > Sent: Monday, February 8, 2021 8:57 PM > To: tanxiaofei > Cc: j...@linux.ibm.com; martin.peter...@oracle.com; > linux-s...@vger.kernel.org; linux-kernel@vger.kernel.org; > linux...@openeuler.org > Subject: [Lin