Messages in this thread |  | | | Date | Tue, 29 Jun 2010 10:14:35 -0500 (CDT) | | From | Christoph Lameter <> | | Subject | Re: [PATCH 2/2] vmscan: don't subtraction of unsined |
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On Mon, 28 Jun 2010, KOSAKI Motohiro wrote:
> It's unsigned. negative mean very big value. so > > "zone_page_state(zone, NR_SLAB_RECLAIMABLE) > slab_reclaimable - nr_pages)" will > be evaluated false.
There were some suggestions on how to address this later in the patch.
> ok, your mysterious 'order' parameter (as pointed [1/2]) almostly prevent this case. > because passing 'order' makes very heavy slab pressure and it avoid negative occur. > > but unnaturall coding style can make confusing to reviewers. ya, it's not > big issue. but I also don't find no fixing reason.
This is not a coding issue but one of logic. The order parameter is mysterious to me too. So is the lru_pages logic.
> > The comparison could be a problem here. So > > > > zone_page_state(zone, NR_SLAB_RECLAIMABLE) + nr_pages > > > slab_reclaimable > > > > ? > > My patch take the same thing. but It avoided two line comparision. > Do you mean you like this style? (personally, I don't). If so, I'll > repost this patch.
Yes. I also do not like long cryptic names for local variables.
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