Messages in this thread | | | Date | Sat, 18 Nov 2006 13:37:53 +0000 (GMT) | From | Hugh Dickins <> | Subject | Re: [PATCH] mm: do not call bad_page on PG_reserved check |
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On Sat, 18 Nov 2006, David Rientjes wrote:
> The return value of free_pages_check() indicates if PG_reserved was set. > If so, the calling functions return immediately and no pages are freed so > there is no need to call bad_page(). > > Cc: Andi Kleen <ak@suse.de> > Cc: Nick Piggin <npiggin@suse.de> > Signed-off-by: David Rientjes <rientjes@cs.washington.edu>
NAK. You're missing the point. If an attempt is made to free a reserved page, it implies that the page reference counting has gone wrong: we want to hear about that (so call bad_page), and we dare not reuse the page (so skip freeing it).
What might be a good change, is to avoid freeing a page which meets _any_ of the criteria for calling bad_page: I often wonder whether to do that, alongside abandoning that hopeless page_mapcount BUG in page_remove_rmap, which has almost(?) never helped lead us to any fix.
Hugh
> --- > mm/page_alloc.c | 1 - > 1 files changed, 0 insertions(+), 1 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index bf2f6cf..99bc29d 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -439,7 +439,6 @@ static inline int free_pages_check(struc > 1 << PG_slab | > 1 << PG_swapcache | > 1 << PG_writeback | > - 1 << PG_reserved | > 1 << PG_buddy )))) > bad_page(page); > if (PageDirty(page)) - 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/
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