Linux-ARM-Kernel Archive on lore.kernel.org
 help / color / Atom feed
From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: mark.rutland@arm.com, mhocko@suse.com, linux-sh@vger.kernel.org,
	peterz@infradead.org, catalin.marinas@arm.com,
	dave.hansen@linux.intel.com, will.deacon@arm.com,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	kvmarm@lists.cs.columbia.edu, mpe@ellerman.id.au,
	linux@armlinux.org.uk, mingo@redhat.com, vbabka@suse.cz,
	rientjes@google.com, marc.zyngier@arm.com,
	rppt@linux.vnet.ibm.com, shakeelb@google.com,
	kirill@shutemov.name, tglx@linutronix.de,
	linux-arm-kernel@lists.infradead.org, ard.biesheuvel@linaro.org,
	robin.murphy@arm.com, steve.capper@arm.com,
	christoffer.dall@arm.com, james.morse@arm.com,
	aneesh.kumar@linux.ibm.com, akpm@linux-foundation.org,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] mm: Introduce GFP_PGTABLE
Date: Sat, 12 Jan 2019 18:25:48 +0530
Message-ID: <9dd9a8ef-8db8-891c-79a9-270ab033037c@arm.com> (raw)
In-Reply-To: <20190112121230.GQ6310@bombadil.infradead.org>



On 01/12/2019 05:42 PM, Matthew Wilcox wrote:
> On Sat, Jan 12, 2019 at 03:56:38PM +0530, Anshuman Khandual wrote:
>> All architectures have been defining their own PGALLOC_GFP as (GFP_KERNEL |
>> __GFP_ZERO) and using it for allocating page table pages.
> 
> Except that's not true.
> 
>> +++ b/arch/x86/mm/pgtable.c
>> @@ -13,19 +13,17 @@ phys_addr_t physical_mask __ro_after_init = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
>>  EXPORT_SYMBOL(physical_mask);
>>  #endif
>>  
>> -#define PGALLOC_GFP (GFP_KERNEL_ACCOUNT | __GFP_ZERO)
>> -
>>  #ifdef CONFIG_HIGHPTE
> 
> ...
> 
>>  pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
>>  {
>> -	return (pte_t *)__get_free_page(PGALLOC_GFP & ~__GFP_ACCOUNT);
>> +	return (pte_t *)__get_free_page(GFP_PGTABLE & ~__GFP_ACCOUNT);
>>  }
> 
> I think x86 was the only odd one out here, but you'll need to try again ...

IIUC the user page table pages need __GFP_ACCOUNT not the kernel ones. Hence
in the above function it clears out __GFP_ACCOUNT for kernel page table page
allocations but where as by default it has got __GFP_ACCOUNT which would be
used for user page tables. Instead we can make X86 user allocations add
__GFP_ACCOUNT (like other archs) to generic GFP_PGTABLE when ever required.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply index

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-01-12 10:26 Anshuman Khandual
2019-01-12 12:12 ` Matthew Wilcox
2019-01-12 12:55   ` Anshuman Khandual [this message]
2019-01-12 13:49   ` Christophe Leroy
2019-01-12 15:49     ` Matthew Wilcox
2019-01-12 16:50       ` Shakeel Butt
2019-01-14  4:28       ` Anshuman Khandual
2019-01-12 16:48 ` Shakeel Butt
2019-01-14  4:14   ` Anshuman Khandual
2019-01-13 17:35 ` Michal Hocko
2019-01-14  4:00   ` Anshuman Khandual
2019-01-14  7:01     ` Michal Hocko
2019-01-15 14:11       ` Anshuman Khandual

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=9dd9a8ef-8db8-891c-79a9-270ab033037c@arm.com \
    --to=anshuman.khandual@arm.com \
    --cc=akpm@linux-foundation.org \
    --cc=aneesh.kumar@linux.ibm.com \
    --cc=ard.biesheuvel@linaro.org \
    --cc=catalin.marinas@arm.com \
    --cc=christoffer.dall@arm.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=james.morse@arm.com \
    --cc=kirill@shutemov.name \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=marc.zyngier@arm.com \
    --cc=mark.rutland@arm.com \
    --cc=mhocko@suse.com \
    --cc=mingo@redhat.com \
    --cc=mpe@ellerman.id.au \
    --cc=peterz@infradead.org \
    --cc=rientjes@google.com \
    --cc=robin.murphy@arm.com \
    --cc=rppt@linux.vnet.ibm.com \
    --cc=shakeelb@google.com \
    --cc=steve.capper@arm.com \
    --cc=tglx@linutronix.de \
    --cc=vbabka@suse.cz \
    --cc=will.deacon@arm.com \
    --cc=willy@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-ARM-Kernel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/0 linux-arm-kernel/git/0.git
	git clone --mirror https://lore.kernel.org/linux-arm-kernel/1 linux-arm-kernel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-arm-kernel linux-arm-kernel/ https://lore.kernel.org/linux-arm-kernel \
		linux-arm-kernel@lists.infradead.org infradead-linux-arm-kernel@archiver.kernel.org
	public-inbox-index linux-arm-kernel


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.infradead.lists.linux-arm-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox