Re: Fw: [PATCH] ia64: race flushing icache in do_no_page path

Hugh Dickins
2007-04-28T05:34:26Z

On Fri, 27 Apr 2007, Rohit Seth wrote:
> On Fri, 2007-04-27 at 15:18 +0100, Hugh Dickins wrote:
>
> Right. Extra flush_icache_page routines will add cost to archs that
> have non-null definition of this routine. BTW, isn't flush_icache_page
> marked for deprecation?

Yes, flush_icache_page is marked for deprecation: but that's hardly
a reason to add another under a different name! (Not quite what you
did, but...)

> lazy_mmu_prot_update was added specifically for notifying change in
> protection. So, in a way it is closer to update_mmu_cache (Which is for
> change in mappings itself). Though for ia64 implementation, this ends
> up flushing the icaches when needed.

The ia64 implementation is the only one which has any use for it, and
it's only interested when it's executable i.e. "lazy_mmu_prot_update"
is a name concealing some overdesign.

> Hopefully my reply is useful.

Yes, thanks Rohit, and I'll want to read through it again later.
In particular, I've now a better idea what's "lazy" about it.

Hugh