Re: [PATCH V2 2/2] LoongArch: Add qspinlock support

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

 



On Thu, Jun 23, 2022 at 4:26 PM Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> On Thu, Jun 23, 2022 at 9:56 AM Huacai Chen <chenhuacai@xxxxxxxxxx> wrote:
> > On Thu, Jun 23, 2022 at 1:45 PM Guo Ren <guoren@xxxxxxxxxx> wrote:
> > >
> > > On Thu, Jun 23, 2022 at 12:46 PM Huacai Chen <chenhuacai@xxxxxxxxxxx> wrote:
> > > >
> > > > On NUMA system, the performance of qspinlock is better than generic
> > > > spinlock. Below is the UnixBench test results on a 8 nodes (4 cores
> > > > per node, 32 cores in total) machine.
>
> You are still missing an explanation here about why this is safe to
> do. Is there are
> architectural guarantee for forward progress, or do you rely on
> specific microarchitectural
> behavior?
>
> > > Could you base the patch on [1]?
> > >
> > > [1] https://lore.kernel.org/linux-riscv/20220621144920.2945595-2-guoren@xxxxxxxxxx/raw
> > I found that whether we use qspinlock or tspinlock, we always use
> > qrwlock, so maybe it is better like this?
> >
> > #ifdef CONFIG_ARCH_USE_QUEUED_SPINLOCKS
> > #include <asm/qspinlock.h>
> > #else
> > #include <asm-generic/tspinlock.h>
> > #endif
> >
> > #include <asm/qrwlock.h>
>
> Yes, that seems better, but I would go one step further and include
> asm-generic/qspinlock.h
> in place of asm/qspinlock.h here: The two architectures that have a
> custom asm/qspinlock.h
> also have a custom asm/spinlock.h, so they have no need to include
> asm-generic/spinlock.h
> either.
Okay, thx Huacai & Arnd

>
>         Arnd



-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/



[Index of Archives]     [Linux Kernel]     [Kernel Newbies]     [x86 Platform Driver]     [Netdev]     [Linux Wireless]     [Netfilter]     [Bugtraq]     [Linux Filesystems]     [Yosemite Discussion]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]

  Powered by Linux