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

From: Andrew Morton <[email-masked]>
Date: Tue, 9 Oct 2012 16:45:14 -0700

On Wed, 10 Oct 2012 10:21:50 +1100 Stephen Rothwell <[email-masked]> 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.