linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
To: Christophe Leroy <christophe.leroy@csgroup.eu>,
	linux-mm@kvack.org, akpm@linux-foundation.org
Cc: kaleshsingh@google.com, npiggin@gmail.com,
	joel@joelfernandes.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v3 8/9] mm/mremap: Allow arch runtime override
Date: Fri, 9 Apr 2021 17:29:25 +0530	[thread overview]
Message-ID: <955e19f7-e15c-d7cc-3cdf-0c237ae980c1@linux.ibm.com> (raw)
In-Reply-To: <c421c3cb-6e9a-6db0-9e4b-f7a7e9a6c1cc@csgroup.eu>

On 4/9/21 3:05 PM, Christophe Leroy wrote:
> 
> 
> Le 30/03/2021 à 08:07, Aneesh Kumar K.V a écrit :
>> Architectures like ppc64 can only support faster mremap only with radix
> 
> ... only .... only ...
> 
>> translation. Hence allow a runtime check w.r.t support for fast mremap.
>>

will fix that

>> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>> ---
>>   arch/arc/include/asm/tlb.h     |  5 +++++
>>   arch/arm64/include/asm/tlb.h   |  6 ++++++
>>   arch/powerpc/include/asm/tlb.h |  6 ++++++
>>   arch/x86/include/asm/tlb.h     |  5 +++++
>>   mm/mremap.c                    | 14 +++++++++++++-
>>   5 files changed, 35 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arc/include/asm/tlb.h b/arch/arc/include/asm/tlb.h
>> index 975b35d3738d..22b8cfb46cbf 100644
>> --- a/arch/arc/include/asm/tlb.h
>> +++ b/arch/arc/include/asm/tlb.h
>> @@ -9,4 +9,9 @@
>>   #include <linux/pagemap.h>
>>   #include <asm-generic/tlb.h>
>> +#define arch_supports_page_tables_move arch_supports_page_tables_move
>> +static inline bool arch_supports_page_tables_move(void)
>> +{
>> +    return true;
>> +}
> 
> I can't see why ARC arch needs that. It neither selects 
> CONFIG_HAVE_MOVE_PMD nor CONFIG_HAVE_MOVE_PUD.
> 
>

ok will fix that (I confused arch/Kconfig with arc/Kconfig )



>>   #endif /* _ASM_ARC_TLB_H */
>> diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
>> index 61c97d3b58c7..fe209efc6a10 100644
>> --- a/arch/arm64/include/asm/tlb.h
>> +++ b/arch/arm64/include/asm/tlb.h
>> @@ -94,4 +94,10 @@ static inline void __pud_free_tlb(struct mmu_gather 
>> *tlb, pud_t *pudp,
>>   }
>>   #endif
>> +#define arch_supports_page_tables_move arch_supports_page_tables_move
>> +static inline bool arch_supports_page_tables_move(void)
>> +{
>> +    return true;
>> +}
>> +
>>   #endif
>> diff --git a/arch/powerpc/include/asm/tlb.h 
>> b/arch/powerpc/include/asm/tlb.h
>> index 160422a439aa..058918a7cd3c 100644
>> --- a/arch/powerpc/include/asm/tlb.h
>> +++ b/arch/powerpc/include/asm/tlb.h
>> @@ -83,5 +83,11 @@ static inline int mm_is_thread_local(struct 
>> mm_struct *mm)
>>   }
>>   #endif
>> +#define arch_supports_page_tables_move arch_supports_page_tables_move
>> +static inline bool arch_supports_page_tables_move(void)
>> +{
>> +    return radix_enabled();
>> +}
>> +
>>   #endif /* __KERNEL__ */
>>   #endif /* __ASM_POWERPC_TLB_H */
>> diff --git a/arch/x86/include/asm/tlb.h b/arch/x86/include/asm/tlb.h
>> index 1bfe979bb9bc..62915238bb36 100644
>> --- a/arch/x86/include/asm/tlb.h
>> +++ b/arch/x86/include/asm/tlb.h
>> @@ -37,4 +37,9 @@ static inline void __tlb_remove_table(void *table)
>>       free_page_and_swap_cache(table);
>>   }
>> +#define arch_supports_page_tables_move arch_supports_page_tables_move
>> +static inline bool arch_supports_page_tables_move(void)
>> +{
>> +    return true;
>> +}
>>   #endif /* _ASM_X86_TLB_H */
>> diff --git a/mm/mremap.c b/mm/mremap.c
>> index 7ac1df8e6d51..4d812af3e44b 100644
>> --- a/mm/mremap.c
>> +++ b/mm/mremap.c
>> @@ -25,7 +25,7 @@
>>   #include <linux/userfaultfd_k.h>
>>   #include <asm/cacheflush.h>
>> -#include <asm/tlbflush.h>
>> +#include <asm/tlb.h>
>>   #include <asm/pgalloc.h>
>>   #include "internal.h"
>> @@ -221,6 +221,14 @@ static inline void flush_pte_tlb_pwc_range(struct 
>> vm_area_struct *vma,
>>   }
>>   #endif
>> +#ifndef arch_supports_page_tables_move
>> +#define arch_supports_page_tables_move arch_supports_page_tables_move
>> +static inline bool arch_supports_page_tables_move(void)
>> +{
>> +    return false;
> 
> Can you do
> 
>      return IS_ENABLED(CONFIG_HAVE_MOVE_PMD) || 
> IS_ENABLED(CONFIG_HAVE_MOVE_PUD);
> 
> And then remove the arch_supports_page_tables_move() you have added for 
> arc, arm64 and x86 ?
> 


something like below?

#ifndef arch_supports_page_tables_move
#define arch_supports_page_tables_move arch_supports_page_tables_move
static inline bool arch_supports_page_tables_move(void)
{
	return IS_ENABLED(CONFIG_HAVE_MOVE_PMD) ||
		IS_ENABLED(CONFIG_HAVE_MOVE_PUD);
}
#endif

are remove those from those arch headers.





>> +}
>> +#endif
>> +
>>   #ifdef CONFIG_HAVE_MOVE_PMD
> 
> Next step could be remove that #ifdef and the content of the matching #else
> For that we'd just need a stub version of set_pmd_at() and set_pud_at().
> 
>>   static bool move_normal_pmd(struct vm_area_struct *vma, unsigned 
>> long old_addr,
>>             unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd)
>> @@ -229,6 +237,8 @@ static bool move_normal_pmd(struct vm_area_struct 
>> *vma, unsigned long old_addr,
>>       struct mm_struct *mm = vma->vm_mm;
>>       pmd_t pmd;
>> +    if (!arch_supports_page_tables_move())
>> +        return false;
>>       /*
>>        * The destination pmd shouldn't be established, free_pgtables()
>>        * should have released it.
>> @@ -295,6 +305,8 @@ static bool move_normal_pud(struct vm_area_struct 
>> *vma, unsigned long old_addr,
>>       struct mm_struct *mm = vma->vm_mm;
>>       pud_t pud;
>> +    if (!arch_supports_page_tables_move())
>> +        return false;
>>       /*
>>        * The destination pud shouldn't be established, free_pgtables()
>>        * should have released it.
>>



  reply	other threads:[~2021-04-09 11:59 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-30  6:07 [PATCH v3 0/9] Speedup mremap on ppc64 Aneesh Kumar K.V
2021-03-30  6:07 ` [PATCH v3 1/9] selftest/mremap_test: Update the test to handle pagesize other than 4K Aneesh Kumar K.V
2021-04-12 18:37   ` Kalesh Singh
2021-03-30  6:07 ` [PATCH v3 2/9] selftest/mremap_test: Avoid crash with static build Aneesh Kumar K.V
2021-04-12 18:38   ` Kalesh Singh
2021-03-30  6:07 ` [PATCH v3 3/9] mm/mremap: Use pmd/pud_poplulate to update page table entries Aneesh Kumar K.V
2021-03-30  6:07 ` [PATCH v3 4/9] powerpc/mm/book3s64: Fix possible build error Aneesh Kumar K.V
2021-04-09  9:15   ` Christophe Leroy
2021-03-30  6:07 ` [PATCH v3 5/9] powerpc/mm/book3s64: Update tlb flush routines to take a page walk cache flush argument Aneesh Kumar K.V
2021-03-30 13:28   ` kernel test robot
2021-04-09  9:18   ` Christophe Leroy
2021-03-30  6:07 ` [PATCH v3 6/9] mm/mremap: Use range flush that does TLB and page walk cache flush Aneesh Kumar K.V
2021-03-30  6:07 ` [PATCH v3 7/9] mm/mremap: Move TLB flush outside page table lock Aneesh Kumar K.V
2021-03-30  6:07 ` [PATCH v3 8/9] mm/mremap: Allow arch runtime override Aneesh Kumar K.V
2021-04-09  9:35   ` Christophe Leroy
2021-04-09 11:59     ` Aneesh Kumar K.V [this message]
2021-03-30  6:07 ` [PATCH v3 9/9] powerpc/mm: Enable move pmd/pud Aneesh Kumar K.V
2021-04-09  5:48 ` [PATCH v3 0/9] Speedup mremap on ppc64 Aneesh Kumar K.V

Reply instructions:

You may reply publicly 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=955e19f7-e15c-d7cc-3cdf-0c237ae980c1@linux.ibm.com \
    --to=aneesh.kumar@linux.ibm.com \
    --cc=akpm@linux-foundation.org \
    --cc=christophe.leroy@csgroup.eu \
    --cc=joel@joelfernandes.org \
    --cc=kaleshsingh@google.com \
    --cc=linux-mm@kvack.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=npiggin@gmail.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).