lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 5 Feb 2020 17:59:24 +0800 From: Wei Yang <richardw.yang@...ux.intel.com> To: David Hildenbrand <david@...hat.com> Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org, linux-arm-kernel@...ts.infradead.org, linux-ia64@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org, linux-s390@...r.kernel.org, linux-sh@...r.kernel.org, x86@...nel.org, Andrew Morton <akpm@...ux-foundation.org>, Oscar Salvador <osalvador@...e.de>, Michal Hocko <mhocko@...e.com>, Pavel Tatashin <pasha.tatashin@...een.com>, Dan Williams <dan.j.williams@...el.com>, Wei Yang <richardw.yang@...ux.intel.com> Subject: Re: [PATCH v6 08/10] mm/memory_hotplug: Don't check for "all holes" in shrink_zone_span() On Sun, Oct 06, 2019 at 10:56:44AM +0200, David Hildenbrand wrote: >If we have holes, the holes will automatically get detected and removed >once we remove the next bigger/smaller section. The extra checks can >go. > >Cc: Andrew Morton <akpm@...ux-foundation.org> >Cc: Oscar Salvador <osalvador@...e.de> >Cc: Michal Hocko <mhocko@...e.com> >Cc: David Hildenbrand <david@...hat.com> >Cc: Pavel Tatashin <pasha.tatashin@...een.com> >Cc: Dan Williams <dan.j.williams@...el.com> >Cc: Wei Yang <richardw.yang@...ux.intel.com> >Signed-off-by: David Hildenbrand <david@...hat.com> >--- > mm/memory_hotplug.c | 34 +++++++--------------------------- > 1 file changed, 7 insertions(+), 27 deletions(-) > >diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c >index f294918f7211..8dafa1ba8d9f 100644 >--- a/mm/memory_hotplug.c >+++ b/mm/memory_hotplug.c >@@ -393,6 +393,9 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > if (pfn) { > zone->zone_start_pfn = pfn; > zone->spanned_pages = zone_end_pfn - pfn; >+ } else { >+ zone->zone_start_pfn = 0; >+ zone->spanned_pages = 0; > } > } else if (zone_end_pfn == end_pfn) { > /* >@@ -405,34 +408,11 @@ static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, > start_pfn); > if (pfn) > zone->spanned_pages = pfn - zone_start_pfn + 1; >+ else { >+ zone->zone_start_pfn = 0; >+ zone->spanned_pages = 0; >+ } > } If it is me, I would like to take out these two similar logic out. For example: if () { } else if () { } else { goto out; } /* The zone has no valid section */ if (!pfn) { zone->zone_start_pfn = 0; zone->spanned_pages = 0; } out: zone_span_writeunlock(zone); Well, this is just my personal taste :-) >- >- /* >- * The section is not biggest or smallest mem_section in the zone, it >- * only creates a hole in the zone. So in this case, we need not >- * change the zone. But perhaps, the zone has only hole data. Thus >- * it check the zone has only hole or not. >- */ >- pfn = zone_start_pfn; >- for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { >- if (unlikely(!pfn_to_online_page(pfn))) >- continue; >- >- if (page_zone(pfn_to_page(pfn)) != zone) >- continue; >- >- /* Skip range to be removed */ >- if (pfn >= start_pfn && pfn < end_pfn) >- continue; >- >- /* If we find valid section, we have nothing to do */ >- zone_span_writeunlock(zone); >- return; >- } >- >- /* The zone has no valid section */ >- zone->zone_start_pfn = 0; >- zone->spanned_pages = 0; > zone_span_writeunlock(zone); > } > >-- >2.21.0 -- Wei Yang Help you, Help me
Powered by blists - more mailing lists