| Message ID | 506D1F1D.9000301@jp.fujitsu.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
CC to Dave Hanse. Hello Dave, I think following patch works both x86 and ppc. but I'm not ppc expert. So I'm glad if you double check it. thank you. <intentional full quote> > When our x86 box calls __remove_pages(), release_mem_region() shows > many warnings. And x86 box cannot unregister iomem_resource. > > "Trying to free nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>" > > release_mem_region() has been changed as called in each PAGES_PER_SECTION > chunk since applying a patch(de7f0cba96786c). Because powerpc registers > iomem_resource in each PAGES_PER_SECTION chunk. But when I hot add memory > on x86 box, iomem_resource is register in each _CRS not PAGES_PER_SECTION > chunk. So x86 box unregisters iomem_resource. > > The patch fixes the problem. > > CC: David Rientjes <rientjes@google.com> > CC: Jiang Liu <liuj97@gmail.com> > CC: Len Brown <len.brown@intel.com> > CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> > CC: Paul Mackerras <paulus@samba.org> > CC: Christoph Lameter <cl@linux.com> > Cc: Minchan Kim <minchan.kim@gmail.com> > CC: Andrew Morton <akpm@linux-foundation.org> > CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > CC: Wen Congyang <wency@cn.fujitsu.com> > Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> > --- > arch/powerpc/platforms/pseries/hotplug-memory.c | 13 +++++++++---- > mm/memory_hotplug.c | 4 ++-- > 2 files changed, 11 insertions(+), 6 deletions(-) > > Index: linux-3.6/arch/powerpc/platforms/pseries/hotplug-memory.c > =================================================================== > --- linux-3.6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-10-04 14:22:59.833520792 +0900 > +++ linux-3.6/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-10-04 14:23:05.150521411 +0900 > @@ -77,7 +77,8 @@ static int pseries_remove_memblock(unsig > { > unsigned long start, start_pfn; > struct zone *zone; > - int ret; > + int i, ret; > + int sections_to_remove; > > start_pfn = base >> PAGE_SHIFT; > > @@ -97,9 +98,13 @@ static int pseries_remove_memblock(unsig > * to sysfs "state" file and we can't remove sysfs entries > * while writing to it. So we have to defer it to here. > */ > - ret = __remove_pages(zone, start_pfn, memblock_size >> PAGE_SHIFT); > - if (ret) > - return ret; > + sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION; > + for (i = 0; i < sections_to_remove; i++) { > + unsigned long pfn = start_pfn + i * PAGES_PER_SECTION; > + ret = __remove_pages(zone, start_pfn, PAGES_PER_SECTION); > + if (ret) > + return ret; > + } > > /* > * Update memory regions for memory remove > Index: linux-3.6/mm/memory_hotplug.c > =================================================================== > --- linux-3.6.orig/mm/memory_hotplug.c 2012-10-04 14:22:59.829520788 +0900 > +++ linux-3.6/mm/memory_hotplug.c 2012-10-04 14:23:25.860527278 +0900 > @@ -362,11 +362,11 @@ int __remove_pages(struct zone *zone, un > BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); > BUG_ON(nr_pages % PAGES_PER_SECTION); > > + release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE); > + > sections_to_remove = nr_pages / PAGES_PER_SECTION; > for (i = 0; i < sections_to_remove; i++) { > unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; > - release_mem_region(pfn << PAGE_SHIFT, > - PAGES_PER_SECTION << PAGE_SHIFT); > ret = __remove_section(zone, __pfn_to_section(pfn)); > if (ret) > break; > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
On Thu, 4 Oct 2012 14:31:09 +0900 Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> wrote: > When our x86 box calls __remove_pages(), release_mem_region() shows > many warnings. And x86 box cannot unregister iomem_resource. > > "Trying to free nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>" > > release_mem_region() has been changed as called in each PAGES_PER_SECTION > chunk since applying a patch(de7f0cba96786c). Because powerpc registers > iomem_resource in each PAGES_PER_SECTION chunk. But when I hot add memory > on x86 box, iomem_resource is register in each _CRS not PAGES_PER_SECTION > chunk. So x86 box unregisters iomem_resource. > > The patch fixes the problem. > > --- linux-3.6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-10-04 14:22:59.833520792 +0900 > +++ linux-3.6/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-10-04 14:23:05.150521411 +0900 > @@ -77,7 +77,8 @@ static int pseries_remove_memblock(unsig > { > unsigned long start, start_pfn; > struct zone *zone; > - int ret; > + int i, ret; > + int sections_to_remove; > > start_pfn = base >> PAGE_SHIFT; > > @@ -97,9 +98,13 @@ static int pseries_remove_memblock(unsig > * to sysfs "state" file and we can't remove sysfs entries > * while writing to it. So we have to defer it to here. > */ > - ret = __remove_pages(zone, start_pfn, memblock_size >> PAGE_SHIFT); > - if (ret) > - return ret; > + sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION; > + for (i = 0; i < sections_to_remove; i++) { > + unsigned long pfn = start_pfn + i * PAGES_PER_SECTION; > + ret = __remove_pages(zone, start_pfn, PAGES_PER_SECTION); > + if (ret) > + return ret; > + } It is inappropriate that `i' have a signed 32-bit type. I doubt if there's any possibility of an overflow bug here, but using a consistent and well-chosen type would eliminate all doubt. Note that __remove_pages() does use an unsigned long for this, although it stupidly calls that variable "i", despite the C programmers' expectation that a variable called "i" has type "int". The same applies to `sections_to_remove', but __remove_pages() went and decided to use an `int' for that variable. Sigh. Anyway, please have a think, and see if we can come up with the best and most accurate choice of types and identifiers in this code.
Index: linux-3.6/arch/powerpc/platforms/pseries/hotplug-memory.c =================================================================== --- linux-3.6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-10-04 14:22:59.833520792 +0900 +++ linux-3.6/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-10-04 14:23:05.150521411 +0900 @@ -77,7 +77,8 @@ static int pseries_remove_memblock(unsig { unsigned long start, start_pfn; struct zone *zone; - int ret; + int i, ret; + int sections_to_remove; start_pfn = base >> PAGE_SHIFT; @@ -97,9 +98,13 @@ static int pseries_remove_memblock(unsig * to sysfs "state" file and we can't remove sysfs entries * while writing to it. So we have to defer it to here. */ - ret = __remove_pages(zone, start_pfn, memblock_size >> PAGE_SHIFT); - if (ret) - return ret; + sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION; + for (i = 0; i < sections_to_remove; i++) { + unsigned long pfn = start_pfn + i * PAGES_PER_SECTION; + ret = __remove_pages(zone, start_pfn, PAGES_PER_SECTION); + if (ret) + return ret; + } /* * Update memory regions for memory remove Index: linux-3.6/mm/memory_hotplug.c =================================================================== --- linux-3.6.orig/mm/memory_hotplug.c 2012-10-04 14:22:59.829520788 +0900 +++ linux-3.6/mm/memory_hotplug.c 2012-10-04 14:23:25.860527278 +0900 @@ -362,11 +362,11 @@ int __remove_pages(struct zone *zone, un BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); BUG_ON(nr_pages % PAGES_PER_SECTION); + release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE); + sections_to_remove = nr_pages / PAGES_PER_SECTION; for (i = 0; i < sections_to_remove; i++) { unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; - release_mem_region(pfn << PAGE_SHIFT, - PAGES_PER_SECTION << PAGE_SHIFT); ret = __remove_section(zone, __pfn_to_section(pfn)); if (ret) break;
When our x86 box calls __remove_pages(), release_mem_region() shows many warnings. And x86 box cannot unregister iomem_resource. "Trying to free nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>" release_mem_region() has been changed as called in each PAGES_PER_SECTION chunk since applying a patch(de7f0cba96786c). Because powerpc registers iomem_resource in each PAGES_PER_SECTION chunk. But when I hot add memory on x86 box, iomem_resource is register in each _CRS not PAGES_PER_SECTION chunk. So x86 box unregisters iomem_resource. The patch fixes the problem. CC: David Rientjes <rientjes@google.com> CC: Jiang Liu <liuj97@gmail.com> CC: Len Brown <len.brown@intel.com> CC: Benjamin Herrenschmidt <benh@kernel.crashing.org> CC: Paul Mackerras <paulus@samba.org> CC: Christoph Lameter <cl@linux.com> Cc: Minchan Kim <minchan.kim@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> CC: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> --- arch/powerpc/platforms/pseries/hotplug-memory.c | 13 +++++++++---- mm/memory_hotplug.c | 4 ++-- 2 files changed, 11 insertions(+), 6 deletions(-)