Date: Tue, 07 Oct 2008 14:04:06 +0200 From: Jille Timmermans <jille@quis.cx> To: Ramachandran Sathyanarayanan <Ramachandran.Sathyanarayanan@aricent.com> Cc: "freebsd-hackers@freebsd.org" <freebsd-hackers@freebsd.org>, Rajeshwar Patil <Rajeshwar.Patil@aricent.com> Subject: Re: sleep is not working to avoid starvation among threads of same priority Message-ID: <48EB5036.80209@quis.cx> In-Reply-To: <B110A82B42E4E547B2A622349609CC1E2D21B5303C@GUREXMB02.ASIAN.AD.ARICENT.COM> References: <B110A82B42E4E547B2A622349609CC1E2D21B5303C@GUREXMB02.ASIAN.AD.ARICENT.COM>
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Hello,
Take a look at pthread_yield():
DESCRIPTION
The pthread_yield() forces the running thread to relinquish the
processor
until it again becomes the head of its thread list.
(Note that it is not portable)
And if you want to use sleep, I found out that using sleep with more ms
does 'yield' the thread/process.
iirc, 20ms was enough to stop it from using 100% CPU.
-- Jille
Ramachandran Sathyanarayanan wrote:
> Hi
>
> I hope this is the right mailer for this question. pls let us know your inputs on this.
>
> Thanks
>
> Ram
>
> ________________________________
> From: Rajeshwar Patil
> Sent: Tuesday, October 07, 2008 3:36 PM
> To: freebsd-questions@freebsd.org
> Cc: Ramachandran Sathyanarayanan; Rajeshwar Patil
> Subject: sleep is not working to avoid starvation among threads of same priority
>
> Hi,
>
> I have two threads of same priority lets say thread A and thread B, thread A is starving since thread B has got a for loop of size 100k. So, to avoid starvation I am processing 1000 iterations of for loop(that of thread B) in one batch and giving sleep of 1ms, but still thread A is starving. If I increase the batch size used in for loop from 1k to 10k then starvation of thread A is little less whereas it should be more as Im increasing processing time of thread B. I tried various combinations of sleeps and batches, but I couldnt solve the starvation of thread A.
>
> Is the sleep right solution?
>
> I will be grateful if someone could answer on this.
>
> Thanks
> Rajeshwar
>
>
>
>
>
>
> ________________________________
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