* [ECOS] Mutex optimization for uncontested cases
@ 2001-09-24 18:40 Luoqi Chen
2001-09-25 12:45 ` Jonathan Larmour
0 siblings, 1 reply; 2+ messages in thread
From: Luoqi Chen @ 2001-09-24 18:40 UTC (permalink / raw)
To: ecos-discuss
I have noticed very poor performance of stdio stream under eCos, about 4 times
slower than vxworks. Howerver I was able to improve the performance by a factor
of 2 by disabling the CYGSEM_LIBC_STDIO_THREAD_SAFE_STREAMS option. This points
to an inefficiency in the current mutex implementation that we do not optimize
for the most common cases of uncontested mutex acquisitions. I wonder if eCos
developers are aware of this problem and if there is any effort under way
trying to resolve it.
-lq
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [ECOS] Mutex optimization for uncontested cases
2001-09-24 18:40 [ECOS] Mutex optimization for uncontested cases Luoqi Chen
@ 2001-09-25 12:45 ` Jonathan Larmour
0 siblings, 0 replies; 2+ messages in thread
From: Jonathan Larmour @ 2001-09-25 12:45 UTC (permalink / raw)
To: Luoqi Chen; +Cc: ecos-discuss
Luoqi Chen wrote:
>
> I have noticed very poor performance of stdio stream under eCos, about 4 times
> slower than vxworks. Howerver I was able to improve the performance by a factor
> of 2 by disabling the CYGSEM_LIBC_STDIO_THREAD_SAFE_STREAMS option. This points
> to an inefficiency in the current mutex implementation that we do not optimize
> for the most common cases of uncontested mutex acquisitions. I wonder if eCos
> developers are aware of this problem and if there is any effort under way
> trying to resolve it.
That's not a priority for us right now. It's open source, so patches
welcome! Bear in mind that atomic test and set type operations aren't
portable :-|.
Jifl
--
Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062
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2001-09-24 18:40 [ECOS] Mutex optimization for uncontested cases Luoqi Chen
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