Re: [PATCH 0 of 4] mm+paravirt+xen: add pte read-modify-write abstraction

From: Jeremy Fitzhardinge
Date: Fri May 23 2008 - 16:43:11 EST

Linus Torvalds wrote:
On Fri, 23 May 2008, Jeremy Fitzhardinge wrote:
This series adds the pte_rmw_start() and pte_rmw_commit() operations,
which change this sequence to:

ptent = pte_rmw_start(mm, addr, pte);
ptent = pte_modify(ptent, newprot);
/* ... */
pte_rmw_commit(mm, addr, pte, ptent);

Can you please rename these.

It's not a general "read-modify-write" operation on the PTE, and this *only* works for changing protection details. In particular, you cannot use pte_rmw_start/commit to change the actual page. So it's very much about just protection bits.

Well, you could use it to update the page and protection bits while preserving the AD bits, but I don't think that's very useful.

It should probably also be called ptep_xyz(), since it takes a pte pointer, not a pte.

So maybe calling it "ptent = ptep_modify_prot_start(..)" ... "ptep_modify_prot_commit(..)" or something.

Yep, sounds fine to me.


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