Re: [PATCH 3/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap

From: kbuild test robot <lkp@intel.com>
To: Alexander Duyck <alexander.duyck@gmail.com>
Cc: pavel.tatashin@microsoft.com, mhocko@suse.com,
	kirill.shutemov@linux.intel.com, linux-nvdimm@lists.01.org,
	dave.hansen@intel.com, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org, jglisse@redhat.com, kbuild-all@01.org,
	akpm@linux-foundation.org, mingo@kernel.org
Subject: Re: [PATCH 3/4] mm: Defer ZONE_DEVICE page initialization to the point where we init pgmap
Date: Tue, 11 Sep 2018 15:49:47 +0800	[thread overview]
Message-ID: <201809111543.e1cQ6zCY%fengguang.wu@intel.com> (raw)
In-Reply-To: <20180910234354.4068.65260.stgit@localhost.localdomain>

Hi Alexander,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v4.19-rc3]
[cannot apply to next-20180910]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Alexander-Duyck/Address-issues-slowing-persistent-memory-initialization/20180911-144536
config: x86_64-randconfig-x009-201836 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   In file included from include/asm-generic/bug.h:5:0,
                    from arch/x86/include/asm/bug.h:83,
                    from include/linux/bug.h:5,
                    from include/linux/mmdebug.h:5,
                    from include/linux/mm.h:9,
                    from mm/page_alloc.c:18:
   mm/page_alloc.c: In function 'memmap_init_zone':
   mm/page_alloc.c:5566:21: error: 'ZONE_DEVICE' undeclared (first use in this function); did you mean 'ZONE_MOVABLE'?
     } else if (zone == ZONE_DEVICE) {
                        ^
   include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
     if (__builtin_constant_p(!!(cond)) ? !!(cond) :   \
                                 ^~~~
>> mm/page_alloc.c:5566:9: note: in expansion of macro 'if'
     } else if (zone == ZONE_DEVICE) {
            ^~
   mm/page_alloc.c:5566:21: note: each undeclared identifier is reported only once for each function it appears in
     } else if (zone == ZONE_DEVICE) {
                        ^
   include/linux/compiler.h:58:30: note: in definition of macro '__trace_if'
     if (__builtin_constant_p(!!(cond)) ? !!(cond) :   \
                                 ^~~~
>> mm/page_alloc.c:5566:9: note: in expansion of macro 'if'
     } else if (zone == ZONE_DEVICE) {
            ^~

vim +/if +5566 mm/page_alloc.c

  5551	
  5552		if (highest_memmap_pfn < end_pfn - 1)
  5553			highest_memmap_pfn = end_pfn - 1;
  5554	
  5555		/*
  5556		 * Honor reservation requested by the driver for this ZONE_DEVICE
  5557		 * memory. We limit the total number of pages to initialize to just
  5558		 * those that might contain the memory mapping. We will defer the
  5559		 * ZONE_DEVICE page initialization until after we have released
  5560		 * the hotplug lock.
  5561		 */
  5562		if (altmap && start_pfn == altmap->base_pfn) {
  5563			start_pfn += altmap->reserve;
  5564			end_pfn = altmap->base_pfn +
  5565				  vmem_altmap_offset(altmap);
> 5566		} else if (zone == ZONE_DEVICE) {
  5567			end_pfn = start_pfn;
  5568		}
  5569	
  5570		for (pfn = start_pfn; pfn < end_pfn; pfn++) {
  5571			/*
  5572			 * There can be holes in boot-time mem_map[]s handed to this
  5573			 * function.  They do not exist on hotplugged memory.
  5574			 */
  5575			if (context != MEMMAP_EARLY)
  5576				goto not_early;
  5577	
  5578			if (!early_pfn_valid(pfn))
  5579				continue;
  5580			if (!early_pfn_in_nid(pfn, nid))
  5581				continue;
  5582			if (!update_defer_init(pgdat, pfn, end_pfn, &nr_initialised))
  5583				break;
  5584	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
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