Re: [PATCH] Snapshot of shared page tables

Dave McCracken (dmccr@us.ibm.com)
Wed, 02 Oct 2002 11:57:26 -0500


--On Wednesday, October 02, 2002 18:51:41 +0200 Daniel Phillips
<phillips@arcor.de> wrote:

> Interesting, you substituted pte_page_lock(ptepage) for
> mm->page_table_lock. Could you wax poetic about that, please?

Sure. If a pte page is shared, the mm->page_table_lock is not sufficient
to protect the rest of the page fault. Therefore we need a lock at the pte
page level. The mm->page_table_lock is held during the page fault until we
have a valid and locked pte page we're working on, then it's dropped for
the rest of the fault.

Feel free to poke holes in my logic, but I think it's the right locking
model for shared pte pages.

Dave McCracken

======================================================================
Dave McCracken IBM Linux Base Kernel Team 1-512-838-3059
dmccr@us.ibm.com T/L 678-3059

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/