Re: x86 ptep_get_and_clear question

From: Ben LaHaise (bcrl@redhat.com)
Date: Fri Feb 16 2001 - 14:42:52 EST


On Fri, 16 Feb 2001, Linus Torvalds wrote:

> This is, actually, a problem that I suspect ends up being _very_ similar
> to the zap_page_range() case. zap_page_range() needs to make sure that
> everything has been updated by the time the page is actually free'd. While
> filemap_sync() needs to make sure that everything has been updated before
> the page is written out (or marked dirty - which obviously also guarantees
> the ordering, and makes the problems look even more similar).

Ah, I see what I was missing. So long as the tlb flush is in between the
ptep_test_and_clear_dirty and the set_page_dirty, we're fine (ie the
current code is good). If we really want to reduce the number of tlb
flushes, yes, we can use the gather code and then just do the
set_page_dirty after a tlb_flush_range.

                -ben

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This archive was generated by hypermail 2b29 : Fri Feb 23 2001 - 21:00:14 EST