Re: Feedback on preemptible kernel patch

[Arjan Filius]

Hello Robert,

I tried 2.4.10-pre4+preempt+this-patch.
Just booted up, and don't notice anything unusual.

On 9 Sep 2001, Robert Love wrote:

> Arjan,
>
> the following patch was written by Manfred Spraul to fix your highmem
> bug.  I haven't had a chance to go over it, but I would like it if you
> could test it.  It can't hurt.  Patch it on top of the preempt patch and
> enable CONFIG_PREEMPT, CONFIG_HIGHMEM, and CONFIG_HIGHMEM_DEBUG.

I found i do anly have a '#define HIGHMEM_DEBUG 1' in
./include/asm/highmem.h, which is default in 2.4.10-pre4.

>
> let me know what happens...any relevant messages, etc. please pass
> along. if it does work, id be curious if they are any slowdowns

Booting up, X, compiling kernel.. no problems.
For speed, i DO notice other processes seem not to wait on that one
programm which has much disk-access, so the (real) sluggish feeling has
gone. This is however with the preempt patch, and the ctx_sw_ patch below
seems only to affect stability in positive sense.

Can you advice what and how to test performance/latency?
The grafics/statistics on the websites you named are impressive..

Greatings,

>
>
> --- highmem.h.prev      Sun Sep  9 08:59:04 2001
> +++ highmem.h   Sun Sep  9 09:00:07 2001
> @@ -88,6 +88,7 @@
>         if (page < highmem_start_page)
>                 return page_address(page);
>
> +       ctx_sw_off();
>         idx = type + KM_TYPE_NR*smp_processor_id();
>         vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
> #if HIGHMEM_DEBUG
> @@ -119,6 +120,7 @@
>         pte_clear(kmap_pte-idx);
>         __flush_tlb_one(vaddr);
> #endif
> +       ctx_sw_on();
> }
>
> #endif /* __KERNEL__ */
>
>
>
>

-- 
Arjan Filius
mailto:[e-mail]