Re: [PATCH] ARM: mm: initialize pfn limits with find_limits()

From: Mike Rapoport
Date: Mon Jan 21 2019 - 16:22:24 EST


On Mon, Jan 21, 2019 at 12:48:09PM -0800, Florian Fainelli wrote:
> On 1/10/19 11:07 AM, Doug Berger wrote:
> > On 12/27/18 3:47 PM, Doug Berger wrote:
> >> The max_low_pfn value must be set before sparse_init() is called to
> >> keep the early memblock allocations and frees balanced for kmemleak
> >> initialization when sparsemem is enabled.
> >>
> >> This commit accomplishes that by replacing the local variables min,
> >> max_low, and max_high with the global limit variables min_low_pfn,
> >> max_low_pfn, and max_pfn respectively in bootmem_init(). The global
> >> variables are initialized directly by find_limits() and used in the
> >> remainder of the function.
> >>
> >> Fixes: 9099daed9c69 ("mm: kmemleak: avoid using __va() on addresses that don't have a lowmem mapping")
> >> Signed-off-by: Doug Berger <opendmb@xxxxxxxxx>
> >> ---
> >> arch/arm/mm/init.c | 20 ++++----------------
> >> 1 file changed, 4 insertions(+), 16 deletions(-)
> >>
> >> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> >> index 32e4845af2b6..98a733f3a5b9 100644
> >> --- a/arch/arm/mm/init.c
> >> +++ b/arch/arm/mm/init.c
> >> @@ -302,15 +302,12 @@ void __init arm_memblock_init(const struct machine_desc *mdesc)
> >>
> >> void __init bootmem_init(void)
> >> {
> >> - unsigned long min, max_low, max_high;
> >> -
> >> memblock_allow_resize();
> >> - max_low = max_high = 0;
> >>
> >> - find_limits(&min, &max_low, &max_high);
> >> + find_limits(&min_low_pfn, &max_low_pfn, &max_pfn);
> >>
> >> - early_memtest((phys_addr_t)min << PAGE_SHIFT,
> >> - (phys_addr_t)max_low << PAGE_SHIFT);
> >> + early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT,
> >> + (phys_addr_t)max_low_pfn << PAGE_SHIFT);
> >>
> >> /*
> >> * Sparsemem tries to allocate bootmem in memory_present(),
> >> @@ -328,16 +325,7 @@ void __init bootmem_init(void)
> >> * the sparse mem_map arrays initialized by sparse_init()
> >> * for memmap_init_zone(), otherwise all PFNs are invalid.
> >> */
> >> - zone_sizes_init(min, max_low, max_high);
> >> -
> >> - /*
> >> - * This doesn't seem to be used by the Linux memory manager any
> >> - * more, but is used by ll_rw_block. If we can get rid of it, we
> >> - * also get rid of some of the stuff above as well.
> >> - */
> >> - min_low_pfn = min;
> >> - max_low_pfn = max_low;
> >> - max_pfn = max_high;
> >> + zone_sizes_init(min_low_pfn, max_low_pfn, max_pfn);
> >> }
> >>
> >> /*
> >>
> >
> > Any feedback on this patch?
>
> Mike, Catalin, does this looks sensible to you? If so, should this be
> thrown into Russell's patch tracking system?

Makes perfect sense to me, so

Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>

> Thanks
> --
> Florian
>

--
Sincerely yours,
Mike.