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RE: memory allocation
- From: Jing Luo <Jing at vicom dot com>
- To: 'Jonathan Larmour' <jlarmour at redhat dot com>
- Cc: 'Ravi Kumar B S' <ravi_kumar at mindtree dot com>, "'ecos-discuss at sources dot redhat dot com'" <ecos-discuss at sources dot redhat dot com>
- Date: Tue, 29 Jan 2002 16:56:46 -0800
- Subject: [ECOS] RE: memory allocation
Hi,
I haven't got answer for the memory allocation and performance for eCos.
For the MAX multi-thread eCos supported, I am not sure that eCos can support
unlimited thread concurrently.
I got the report on internet, it said the max thread priorities eCos can
support is 32. I don't know if it is changed.
http://www.dedicated-systems.com/encyc/buyersguide/rtos/Object153.html
I checked the online document, the current released eCos version is 1.4. But
all the discussion are based on 1.3.1.
And the CVS site has the source code for 1.3.1.
http://sources.redhat.com/ecos/docs-latest/tutorials/arm/ecos-tutorial.3.htm
l#pgfId=1065235
Can you confirm with me what the current release eCos version?
Thanks a lot,
-----Original Message-----
From: Jing Luo
Sent: Saturday, January 26, 2002 4:25 PM
To: 'Jonathan Larmour'; Jing Luo
Cc: 'Ravi Kumar B S'; ecos-discuss@sources.redhat.com
Subject: memory allocation
Thanks for your reply.
I want to clarify my question for Memory allocation.
I want to know the following detailed information about memory allocation in
eCos.
1. Do you have benchmark for memory allocation? in Deterministic or
non-deterministic mode?
I would appreciate if anyone can give more detailed benchmark for message
transactions on Intel Xscale. such as memory allocation, message
send,dispatch/schedule switching, message receive time.
2. Does eCos have the capability for memory allocation to user processes,
including management of shared memory space ?
3. Does eCos have protection from user corruption of system memory space ?
4. Does eCos allow multiple threads (within the same group) share a
(protected) memory space?
And additional question about eCos:
1. Does eCos have porting experience for distributed RTOS?
2. Does eCos have porting experience on multiprocessing porting, especially
on Intel Xscale?
-----Original Message-----
From: Jonathan Larmour [mailto:jlarmour@redhat.com]
Sent: Friday, January 25, 2002 2:00 PM
To: Jing Luo
Cc: 'Ravi Kumar B S'; ecos-discuss@sources.redhat.com
Subject: Re: [ECOS] round-robin
Jing Luo wrote:
>
> Hi Ravi,
> Thanks for your reply.
>
> I am working on Intel 80200 based on Xscale Microarchitecture.
> Does someone have experience to port eCos on this microprocessor?
> I am trying to evaluate eCos to see if it fits our requirement.
> I have some more questions about eCos on Xscale, wish someone can give me
a
> hand.
>
> 1. Does eCos have task limitation on Xscale in Multitasking?
eCos is multi-threaded, not multi-tasking. A lot of efficient RTOS's are
like that to avoid the overhead of task switching.
As for the number of threads, there isn't any real limit using the default
multi-level queue scheduler.
> 2. Pend on the logical AND/OR of event flags is available?
Yes eCos has a "flags" synchronization object, an idea based on uItron (and
used by the uItron compatibility layer).
> 3. How eCos dealing with memory partition services?
What do you mean?
Jifl
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