From: Roman Gushchin <guro@fb.com>
To: "Song Bao Hua (Barry Song)" <song.bao.hua@hisilicon.com>
Cc: Will Deacon <will@kernel.org>,
"catalin.marinas@arm.com" <catalin.marinas@arm.com>,
"nsaenzjulienne@suse.de" <nsaenzjulienne@suse.de>,
"steve.capper@arm.com" <steve.capper@arm.com>,
"rppt@linux.ibm.com" <rppt@linux.ibm.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linuxarm <linuxarm@huawei.com>,
Matthias Brugger <matthias.bgg@gmail.com>
Subject: Re: [PATCH v2] arm64: mm: reserve hugetlb CMA after numa_init
Date: Wed, 17 Jun 2020 11:20:26 -0700 [thread overview]
Message-ID: <20200617182026.GA19784@carbon.dhcp.thefacebook.com> (raw)
In-Reply-To: <B926444035E5E2439431908E3842AFD2502AA9@DGGEMI525-MBS.china.huawei.com>
On Wed, Jun 17, 2020 at 11:38:03AM +0000, Song Bao Hua (Barry Song) wrote:
>
>
> > -----Original Message-----
> > From: Will Deacon [mailto:will@kernel.org]
> > Sent: Wednesday, June 17, 2020 10:18 PM
> > To: Song Bao Hua (Barry Song) <song.bao.hua@hisilicon.com>
> > Cc: catalin.marinas@arm.com; nsaenzjulienne@suse.de;
> > steve.capper@arm.com; rppt@linux.ibm.com; akpm@linux-foundation.org;
> > linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Linuxarm
> > <linuxarm@huawei.com>; Matthias Brugger <matthias.bgg@gmail.com>;
> > Roman Gushchin <guro@fb.com>
> > Subject: Re: [PATCH v2] arm64: mm: reserve hugetlb CMA after numa_init
> >
> > On Wed, Jun 17, 2020 at 10:19:24AM +1200, Barry Song wrote:
> > > hugetlb_cma_reserve() is called at the wrong place. numa_init has not been
> > > done yet. so all reserved memory will be located at node0.
> > >
> > > Fixes: cf11e85fc08c ("mm: hugetlb: optionally allocate gigantic hugepages
> > using cma")
> >
> > Damn, wasn't CC'd on that :/
> >
> > > Cc: Matthias Brugger <matthias.bgg@gmail.com>
> > > Acked-by: Roman Gushchin <guro@fb.com>
> > > Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
> > > ---
> > > -v2: add Fixes tag according to Matthias Brugger's comment
> > >
> > > arch/arm64/mm/init.c | 10 +++++-----
> > > 1 file changed, 5 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
> > > index e631e6425165..41914b483d54 100644
> > > --- a/arch/arm64/mm/init.c
> > > +++ b/arch/arm64/mm/init.c
> > > @@ -404,11 +404,6 @@ void __init arm64_memblock_init(void)
> > > high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
> > >
> > > dma_contiguous_reserve(arm64_dma32_phys_limit);
> > > -
> > > -#ifdef CONFIG_ARM64_4K_PAGES
> > > - hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
> > > -#endif
> >
> > Why is this dependent on CONFIG_ARM64_4K_PAGES? We unconditionally
> > select ARCH_HAS_GIGANTIC_PAGE so this seems unnecessary.
>
> Roman, would you like to answer this question? Have you found any problem if system
> doesn't set 4K_PAGES?
No, I was just following the code in arch/arm64/mm/hugetlbpage.c where all
related to PUD-sized pages is guarded by CONFIG_ARM64_4K_PAGES.
Actually I did all my testing on x86-64, I don't even have any arm hardware.
I'm totally fine with removing this #ifdef if it's not needed.
Thanks!
>
> >
> > > -
> > > }
> > >
> > > void __init bootmem_init(void)
> > > @@ -424,6 +419,11 @@ void __init bootmem_init(void)
> > > min_low_pfn = min;
> > >
> > > arm64_numa_init();
> > > +
> > > +#ifdef CONFIG_ARM64_4K_PAGES
> > > + hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
> > > +#endif
> >
> > A comment here wouldn't hurt, as it does look a lot more natural next
> > to dma_contiguous_reserve().
>
> Will add some comment here.
>
> >
> > Will
>
> barry
next prev parent reply other threads:[~2020-06-17 18:22 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-16 22:19 [PATCH v2] arm64: mm: reserve hugetlb CMA after numa_init Barry Song
2020-06-17 4:12 ` Anshuman Khandual
2020-06-17 9:38 ` Matthias Brugger
2020-06-17 10:18 ` Will Deacon
2020-06-17 11:38 ` Song Bao Hua (Barry Song)
2020-06-17 18:20 ` Roman Gushchin [this message]
2020-06-17 21:43 ` Song Bao Hua (Barry Song)
2020-06-18 7:19 ` Will Deacon
2020-06-18 7:43 ` Song Bao Hua (Barry Song)
2020-06-18 7:44 ` Will Deacon
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