Re: [RFC PATCH 0/6] Convert all tasklets to workqueues

[Dan Williams]

On 6/25/07, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> On Mon, 2007-06-25 at 18:46 -0700, Dan Williams wrote:
> >
> > Context switches on this platform flush the L1 cache so bouncing
> > between a workqueue and the MD thread is painful.
>
> Why is context switches between two kernel threads flushing the L1
> cache?  Is this a flaw in the ARM arch?  I would think the only thing
> that needs to be done between a context switch of two kernel threads (or
> even a user thread to a kernel thread) is update the general regs and
> stack. The memory access (page_tables or whatever ARM uses) should stay
> the same.
Yes you are right, ARM does not flush L1 when prev==next in switch_mm.

> Perhaps something else is at fault here.
I'll try and dig a bit deeper...
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