Re: [PATCH] arch/tile: optimize icache flush

[Rik van Riel]

On 03/10/2011 01:05 PM, Chris Metcalf wrote:
> Tile has incoherent icaches, so they must be explicitly invalidated
> when necessary.  Until now we have done so at tlb flush and context
> switch time, which means more invalidation than strictly necessary.
> The new model for icache flush is:
>
> - When we fault in a page as executable, we set an "Exec" bit in the
>    "struct page" information; the bit stays set until page free time.
>    (We use the arch_1 page bit for our "Exec" bit.)
>
> - At page free time, if the Exec bit is set, we do an icache flush.
>    This should happen relatively rarely: e.g., deleting a binary from disk,
>    or evicting a binary's pages from the page cache due to memory pressure.
>
> Signed-off-by: Chris Metcalf<cmetcalf@xxxxxxxxxx>

Nice trick.

Acked-by: Rik van Riel <riel@xxxxxxxxxx>

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