linux-next: build failure after merge of the origin tree

Hi Linus,

In Linus' tree, today's linux-next build (powerpc ppc64_defconfig) failed
like this:

arch/powerpc/platforms/pseries/hotplug-memory.c: In function 'pseries_remove_memblock':
arch/powerpc/platforms/pseries/hotplug-memory.c:103:17: error: unused variable 'pfn' [-Werror=unused-variable]

Caused by commit d760afd4d257 ("memory-hotplug: suppress "Trying to free
nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>" warning").

I can't see what the point of the "pfn" variable is and this patch never
appeared in linux-next before being merged.  :-(

I have reverted that commit for today.

If this patch truly was authored yesterday (according the Author Date in
git), why was it merged yesterday while still under discussion?  And the
latest update to it still has this build problem ... did anyone even try
to build this for powerpc (since that architecture was obviously
affected)?  (Cross compilers available here
http://www.kernel.org/pub/tools/crosstool/).

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

On Wed, 10 Oct 2012 10:21:50 +1100 Stephen Rothwell [off-list ref] wrote:

Hi Linus,

In Linus' tree, today's linux-next build (powerpc ppc64_defconfig) failed
like this:

arch/powerpc/platforms/pseries/hotplug-memory.c: In function 'pseries_remove_memblock':
arch/powerpc/platforms/pseries/hotplug-memory.c:103:17: error: unused variable 'pfn' [-Werror=unused-variable]

Caused by commit d760afd4d257 ("memory-hotplug: suppress "Trying to free
nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>" warning").

I can't see what the point of the "pfn" variable is

This:

--- a/arch/powerpc/platforms/pseries/hotplug-memory.c~a
+++ a/arch/powerpc/platforms/pseries/hotplug-memory.c

@@ -101,7 +101,7 @@ static int pseries_remove_memblock(unsig
 	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);
+		ret = __remove_pages(zone, pfn, PAGES_PER_SECTION);
 		if (ret)
 			return ret;
 	}

and this patch never
appeared in linux-next before being merged.  :-(

It was first sighted October 3.

I have reverted that commit for today.

If this patch truly was authored yesterday (according the Author Date in
git), why was it merged yesterday while still under discussion?  And the
latest update to it still has this build problem ... did anyone even try
to build this for powerpc (since that architecture was obviously
affected)?

Apparently not - the ppc bit was a best-effort fixup for a patch which
addresses an x86 problem.

Hi Stephen,

2012/10/10 8:45, Andrew Morton wrote:

I believe the error to be fixed with this patch.
Could you try it?

Thanks,
Yasuaki Ishimatsu

quoted

and this patch never
appeared in linux-next before being merged.  :-(

It was first sighted October 3.

quoted

I have reverted that commit for today.

If this patch truly was authored yesterday (according the Author Date in
git), why was it merged yesterday while still under discussion?  And the
latest update to it still has this build problem ... did anyone even try
to build this for powerpc (since that architecture was obviously
affected)?

Apparently not - the ppc bit was a best-effort fixup for a patch which
addresses an x86 problem.

Hi Andrew,

On Tue, 9 Oct 2012 16:45:14 -0700 Andrew Morton [off-list ref] wrote:

Can we get that fix to Linus ASAP, please?

quoted

and this patch never
appeared in linux-next before being merged.  :-(

It was first sighted October 3.

Yeah, my mistake. But it never made it to linux-next.

quoted

I have reverted that commit for today.

If this patch truly was authored yesterday (according the Author Date in
git), why was it merged yesterday while still under discussion?  And the
latest update to it still has this build problem ... did anyone even try
to build this for powerpc (since that architecture was obviously
affected)?

Apparently not - the ppc bit was a best-effort fixup for a patch which
addresses an x86 problem.

Right, and that is one of the reasons we have linux-next - to test for
cross architecture problems.
-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

Hi,

On Wed, 10 Oct 2012 08:52:21 +0900 Yasuaki Ishimatsu [off-list ref] wrote:

2012/10/10 8:45, Andrew Morton wrote:

quoted

On Wed, 10 Oct 2012 10:21:50 +1100 Stephen Rothwell [off-list ref] wrote:

quoted

Hi Linus,

In Linus' tree, today's linux-next build (powerpc ppc64_defconfig) failed
like this:

arch/powerpc/platforms/pseries/hotplug-memory.c: In function 'pseries_remove_memblock':
arch/powerpc/platforms/pseries/hotplug-memory.c:103:17: error: unused variable 'pfn' [-Werror=unused-variable]

Caused by commit d760afd4d257 ("memory-hotplug: suppress "Trying to free
nonexistent resource <XXXXXXXXXXXXXXXX-YYYYYYYYYYYYYYYY>" warning").

I can't see what the point of the "pfn" variable is

This:

--- a/arch/powerpc/platforms/pseries/hotplug-memory.c~a
+++ a/arch/powerpc/platforms/pseries/hotplug-memory.c

@@ -101,7 +101,7 @@ static int pseries_remove_memblock(unsig
  	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);
+		ret = __remove_pages(zone, pfn, PAGES_PER_SECTION);
  		if (ret)
  			return ret;
  	}

I believe the error to be fixed with this patch.
Could you try it?

The certainly fixes the build problem.  I can't comment in the semantics
of the patch.

Tested-by: Stephen Rothwell <redacted>  (Build only)
-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au