From: Benjamin Herrenschmidt <[email protected]>
Date: Mon, 26 Sep 2005 16:22:05 +1000
> The problem is that want to only ever do that kind of hw TLB pre-fill
> when update_mmu_cache() is called as the result an actual fault.
> However, for some reasons that I'm not 100% sure about (*)
> update_mmu_cache() is called from other places, typically in mm/fremap.c
> which aren't directly results of faults.
>
> So I suggest adding an argument to it "int is_fault", that would
> basically be '1' on all the call sites in mm/memory.c and '0' in all the
> call sites in mm/fremap.c.
You can track this in your port specific code. That's what I do on
sparc64 to deal with this case. I record the TLB miss type (D or I
tlb), and also whether a write occurred, in a bitmask. Then I check
this in update_mmu_cache() to decide whether to prefill.
I store it in current_thread_info() and clear it at the end of fault
processing.
Just grep for "FAULT_CODE_*" in the sparc64 code to see how this
works.
Although, I'm ambivalent as to whether prefilling helps at all.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
| |
 |