[lkml]   [2005]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [patch 6/12] mm: remove bad_range
Dave Hansen wrote:

> I seem to also remember a case with this bad_range() check was useful
> for zones that don't have their boundaries aligned on a MAX_ORDER
> boundary. Would this change break such a zone? Do we care?

Hmm, I guess that would be covered by the:

if (page_to_pfn(page) >= zone->zone_start_pfn + zone->spanned_pages)
return 1;
if (page_to_pfn(page) < zone->zone_start_pfn)
return 1;

checks in bad_range. ISTR some "warning: zone not aligned, kernel
*will* crash" message got printed in that case. I always thought
that zones were supposed to be MAX_ORDER aligned, but I can see how
that restriction might be relaxed with these checks in place.

This commit introduced the change:;a=commitdiff;h=d60c9dbc4589766ef5fe88f082052ccd4ecaea59

I think this basically says that architectures who care need to define
CONFIG_HOLES_IN_ZONE and handle this in pfn_valid.

Unless this is a very common requirement and such a solution would have
too much performance cost? Anyone?

SUSE Labs, Novell Inc.

Send instant messages to your online friends

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

 \ /
  Last update: 2005-11-23 02:09    [W:0.076 / U:0.668 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site