From: Andi Kleen <[EMAIL PROTECTED]>
Date: Sat, 17 Nov 2007 22:46:40 +0100
> > The 25.000.000 ns and 88.000.000 ns numbers where on an empty table, but
> > large (16 MB of memory)
>
> This would mean that cond_resched() needs ~4x as much time as checking
> an empty bucket. I find that somewhat h
> The 25.000.000 ns and 88.000.000 ns numbers where on an empty table, but
> large (16 MB of memory)
This would mean that cond_resched() needs ~4x as much time as checking
an empty bucket. I find that somewhat hard to believe.
-Andi
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Andi Kleen a écrit :
Eric Dumazet <[EMAIL PROTECTED]> writes:
So it may sound unnecessary but in the rt_check_expire() case, with a
loop potentially doing XXX.XXX iterations, being able to bypass the
function call is a clear win (in my bench case, 25 ms instead of 88
ms). Impact on I-cache is i
Eric Dumazet <[EMAIL PROTECTED]> writes:
> So it may sound unnecessary but in the rt_check_expire() case, with a
> loop potentially doing XXX.XXX iterations, being able to bypass the
> function call is a clear win (in my bench case, 25 ms instead of 88
> ms). Impact on I-cache is irrelevant here a
From: Arjan van de Ven <[EMAIL PROTECTED]>
Date: Thu, 15 Nov 2007 19:38:02 -0800
> On Thu, 15 Nov 2007 04:01:48 GMT
> Linux Kernel Mailing List <[EMAIL PROTECTED]> wrote:
>
> > Using a "if (need_resched())" test before calling
> > "cond_resched();" is necessary to avoid spending too much time
From: Eric Dumazet <[EMAIL PROTECTED]>
Date: Thu, 15 Nov 2007 09:25:59 +0100
> Please note that :
>
> if (need_resched())
> cond_resched();
>
> will re-test need_resched() once cond_resched() is called.
>
> So it may sound unnecessary but in the rt_check_expire() case, with a loop
> poten
From: Andi Kleen <[EMAIL PROTECTED]>
Date: Thu, 15 Nov 2007 08:30:16 +0100
> Eric Dumazet <[EMAIL PROTECTED]> writes:
> >
> > Using a "if (need_resched())" test before calling "cond_resched();" is
> > necessary to avoid spending too much time doing the resched check.
>
> The only difference betwe
Andi Kleen a écrit :
Eric Dumazet <[EMAIL PROTECTED]> writes:
Using a "if (need_resched())" test before calling "cond_resched();" is
necessary to avoid spending too much time doing the resched check.
The only difference between cond_resched() and if (need_resched())
cond_resched() is one funct
Andi Kleen <[EMAIL PROTECTED]> wrote:
>
> A cheaper change might have been to just limit the number of buckets
> scanned.
Actually the whole point of moving it out to process context
is so that we don't have to worry about keeping track of the number
of buckets since deciding on how many buckets t
Eric Dumazet <[EMAIL PROTECTED]> writes:
>
> Using a "if (need_resched())" test before calling "cond_resched();" is
> necessary to avoid spending too much time doing the resched check.
The only difference between cond_resched() and if (need_resched())
cond_resched() is one function call less and o
From: Eric Dumazet <[EMAIL PROTECTED]>
Date: Wed, 14 Nov 2007 22:34:13 +0100
> On commit 39c90ece7565f5c47110c2fa77409d7a9478bd5b we converted
> rt_check_expire() from softirq to workqueue, allowing the function to perform
> all work it was supposed to do.
>
> When the IP route cache is big, rt
On commit 39c90ece7565f5c47110c2fa77409d7a9478bd5b we converted
rt_check_expire() from softirq to workqueue, allowing the function to perform
all work it was supposed to do.
When the IP route cache is big, rt_check_expire() can take a long time to run.
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