Re: x86 ptep_get_and_clear question

From: Jamie Lokier (
Date: Fri Feb 16 2001 - 12:20:20 EST

Manfred Spraul wrote:
> Ok, Is there one case were your pragmatic solutions is vastly faster?

> * mprotect: No. The difference is at most one additional locked
> instruction for each pte.

Oh, what instruction is that?

> * munmap(anon): No. We must handle delayed accessed anyway (don't call
> free_pages_ok() until flush_tlb_ipi returned). The difference is that we
> might have to perform a second pass to clear any spurious 0x40 bits.

That second pass is what I had in mind.

> * munmap(file): No. Second pass required for correct msync behaviour.

It is?

-- Jamie

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Fri Feb 23 2001 - 21:00:13 EST