diff mbox series

[v5,5/5] memblock: Disable mirror feature if kernelcore is not specified

Message ID 20220614092156.1972846-6-mawupeng1@huawei.com (mailing list archive)
State New, archived
Headers show
Series introduce mirrored memory support for arm64 | expand

Commit Message

mawupeng June 14, 2022, 9:21 a.m. UTC
From: Ma Wupeng <mawupeng1@huawei.com>

If system have some mirrored memory and mirrored feature is not specified
in boot parameter, the basic mirrored feature will be enabled and this will
lead to the following situations:

- memblock memory allocation prefers mirrored region. This may have some
  unexpected influence on numa affinity.

- contiguous memory will be split into several parts if parts of them
  is mirrored memory via memblock_mark_mirror().

To fix this, variable mirrored_kernelcore will be checked in
memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff
kernelcore=mirror is added in the kernel parameters.

Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
---
 mm/internal.h   | 2 ++
 mm/memblock.c   | 3 +++
 mm/page_alloc.c | 2 +-
 3 files changed, 6 insertions(+), 1 deletion(-)

Comments

Baoquan He June 14, 2022, 10:20 a.m. UTC | #1
On 06/14/22 at 05:21pm, Wupeng Ma wrote:
> From: Ma Wupeng <mawupeng1@huawei.com>
> 
> If system have some mirrored memory and mirrored feature is not specified
> in boot parameter, the basic mirrored feature will be enabled and this will
> lead to the following situations:
> 
> - memblock memory allocation prefers mirrored region. This may have some
>   unexpected influence on numa affinity.
> 
> - contiguous memory will be split into several parts if parts of them
>   is mirrored memory via memblock_mark_mirror().
> 
> To fix this, variable mirrored_kernelcore will be checked in
> memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff
> kernelcore=mirror is added in the kernel parameters.
> 
> Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
> Acked-by: Ard Biesheuvel <ardb@kernel.org>
> ---
>  mm/internal.h   | 2 ++
>  mm/memblock.c   | 3 +++
>  mm/page_alloc.c | 2 +-
>  3 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/internal.h b/mm/internal.h
> index c0f8fbe0445b..ddd2d6a46f1b 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -861,4 +861,6 @@ struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
>  
>  DECLARE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
>  
> +extern bool mirrored_kernelcore;
> +
>  #endif	/* __MM_INTERNAL_H */
> diff --git a/mm/memblock.c b/mm/memblock.c
> index b1d2a0009733..a9f18b988b7f 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -924,6 +924,9 @@ int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
>   */
>  int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
>  {
> +	if (!mirrored_kernelcore)
> +		return 0;

memblock_mark_mirror() is just a wrapper, maybe we should check this in
efi_find_mirror(). Otherwise, how do we explain the message printed out
at below in boot log if we don't mark mirror memory at all?

void __init efi_find_mirror(void)
{
......
	if (mirror_size)
                pr_info("Memory: %lldM/%lldM mirrored memory\n",
                        mirror_size>>20, total_size>>20);
}

> +
>  	system_has_some_mirror = true;
>  
>  	return memblock_setclr_flag(base, size, 1, MEMBLOCK_MIRROR);
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e008a3df0485..10dc35ec7479 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -356,7 +356,7 @@ static unsigned long required_kernelcore_percent __initdata;
>  static unsigned long required_movablecore __initdata;
>  static unsigned long required_movablecore_percent __initdata;
>  static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata;
> -static bool mirrored_kernelcore __meminitdata;
> +bool mirrored_kernelcore __initdata_memblock;
>  
>  /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
>  int movable_zone;
> -- 
> 2.25.1
> 
>
Ard Biesheuvel June 14, 2022, 10:27 a.m. UTC | #2
On Tue, 14 Jun 2022 at 12:20, Baoquan He <bhe@redhat.com> wrote:
>
> On 06/14/22 at 05:21pm, Wupeng Ma wrote:
> > From: Ma Wupeng <mawupeng1@huawei.com>
> >
> > If system have some mirrored memory and mirrored feature is not specified
> > in boot parameter, the basic mirrored feature will be enabled and this will
> > lead to the following situations:
> >
> > - memblock memory allocation prefers mirrored region. This may have some
> >   unexpected influence on numa affinity.
> >
> > - contiguous memory will be split into several parts if parts of them
> >   is mirrored memory via memblock_mark_mirror().
> >
> > To fix this, variable mirrored_kernelcore will be checked in
> > memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff
> > kernelcore=mirror is added in the kernel parameters.
> >
> > Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
> > Acked-by: Ard Biesheuvel <ardb@kernel.org>
> > ---
> >  mm/internal.h   | 2 ++
> >  mm/memblock.c   | 3 +++
> >  mm/page_alloc.c | 2 +-
> >  3 files changed, 6 insertions(+), 1 deletion(-)
> >
> > diff --git a/mm/internal.h b/mm/internal.h
> > index c0f8fbe0445b..ddd2d6a46f1b 100644
> > --- a/mm/internal.h
> > +++ b/mm/internal.h
> > @@ -861,4 +861,6 @@ struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
> >
> >  DECLARE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
> >
> > +extern bool mirrored_kernelcore;
> > +
> >  #endif       /* __MM_INTERNAL_H */
> > diff --git a/mm/memblock.c b/mm/memblock.c
> > index b1d2a0009733..a9f18b988b7f 100644
> > --- a/mm/memblock.c
> > +++ b/mm/memblock.c
> > @@ -924,6 +924,9 @@ int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
> >   */
> >  int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
> >  {
> > +     if (!mirrored_kernelcore)
> > +             return 0;
>
> memblock_mark_mirror() is just a wrapper, maybe we should check this in
> efi_find_mirror(). Otherwise, how do we explain the message printed out
> at below in boot log if we don't mark mirror memory at all?
>
> void __init efi_find_mirror(void)
> {
> ......
>         if (mirror_size)
>                 pr_info("Memory: %lldM/%lldM mirrored memory\n",
>                         mirror_size>>20, total_size>>20);
> }
>

EFI does not care about *how* mirrored memory is being used or not, it
just reports what the firmware provided. So EFI is not the appropriate
level to take kernelcore=mirror into account.

I already mentioned that memblock_mark_mirror() is also the wrong
place IMO, but Kefeng explained that doing it elsewhere is
problematic.
Baoquan He June 14, 2022, 10:50 a.m. UTC | #3
On 06/14/22 at 12:27pm, Ard Biesheuvel wrote:
> On Tue, 14 Jun 2022 at 12:20, Baoquan He <bhe@redhat.com> wrote:
> >
> > On 06/14/22 at 05:21pm, Wupeng Ma wrote:
> > > From: Ma Wupeng <mawupeng1@huawei.com>
> > >
> > > If system have some mirrored memory and mirrored feature is not specified
> > > in boot parameter, the basic mirrored feature will be enabled and this will
> > > lead to the following situations:
> > >
> > > - memblock memory allocation prefers mirrored region. This may have some
> > >   unexpected influence on numa affinity.
> > >
> > > - contiguous memory will be split into several parts if parts of them
> > >   is mirrored memory via memblock_mark_mirror().
> > >
> > > To fix this, variable mirrored_kernelcore will be checked in
> > > memblock_mark_mirror(). Mark mirrored memory with flag MEMBLOCK_MIRROR iff
> > > kernelcore=mirror is added in the kernel parameters.
> > >
> > > Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
> > > Acked-by: Ard Biesheuvel <ardb@kernel.org>
> > > ---
> > >  mm/internal.h   | 2 ++
> > >  mm/memblock.c   | 3 +++
> > >  mm/page_alloc.c | 2 +-
> > >  3 files changed, 6 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/mm/internal.h b/mm/internal.h
> > > index c0f8fbe0445b..ddd2d6a46f1b 100644
> > > --- a/mm/internal.h
> > > +++ b/mm/internal.h
> > > @@ -861,4 +861,6 @@ struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
> > >
> > >  DECLARE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
> > >
> > > +extern bool mirrored_kernelcore;
> > > +
> > >  #endif       /* __MM_INTERNAL_H */
> > > diff --git a/mm/memblock.c b/mm/memblock.c
> > > index b1d2a0009733..a9f18b988b7f 100644
> > > --- a/mm/memblock.c
> > > +++ b/mm/memblock.c
> > > @@ -924,6 +924,9 @@ int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
> > >   */
> > >  int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
> > >  {
> > > +     if (!mirrored_kernelcore)
> > > +             return 0;
> >
> > memblock_mark_mirror() is just a wrapper, maybe we should check this in
> > efi_find_mirror(). Otherwise, how do we explain the message printed out
> > at below in boot log if we don't mark mirror memory at all?
> >
> > void __init efi_find_mirror(void)
> > {
> > ......
> >         if (mirror_size)
> >                 pr_info("Memory: %lldM/%lldM mirrored memory\n",
> >                         mirror_size>>20, total_size>>20);
> > }
> >
> 
> EFI does not care about *how* mirrored memory is being used or not, it
> just reports what the firmware provided. So EFI is not the appropriate
> level to take kernelcore=mirror into account.
> 
> I already mentioned that memblock_mark_mirror() is also the wrong
> place IMO, but Kefeng explained that doing it elsewhere is
> problematic.

OK, seems we have no better choice other than these two. 

>
diff mbox series

Patch

diff --git a/mm/internal.h b/mm/internal.h
index c0f8fbe0445b..ddd2d6a46f1b 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -861,4 +861,6 @@  struct folio *try_grab_folio(struct page *page, int refs, unsigned int flags);
 
 DECLARE_PER_CPU(struct per_cpu_nodestat, boot_nodestats);
 
+extern bool mirrored_kernelcore;
+
 #endif	/* __MM_INTERNAL_H */
diff --git a/mm/memblock.c b/mm/memblock.c
index b1d2a0009733..a9f18b988b7f 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -924,6 +924,9 @@  int __init_memblock memblock_clear_hotplug(phys_addr_t base, phys_addr_t size)
  */
 int __init_memblock memblock_mark_mirror(phys_addr_t base, phys_addr_t size)
 {
+	if (!mirrored_kernelcore)
+		return 0;
+
 	system_has_some_mirror = true;
 
 	return memblock_setclr_flag(base, size, 1, MEMBLOCK_MIRROR);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e008a3df0485..10dc35ec7479 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -356,7 +356,7 @@  static unsigned long required_kernelcore_percent __initdata;
 static unsigned long required_movablecore __initdata;
 static unsigned long required_movablecore_percent __initdata;
 static unsigned long zone_movable_pfn[MAX_NUMNODES] __initdata;
-static bool mirrored_kernelcore __meminitdata;
+bool mirrored_kernelcore __initdata_memblock;
 
 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
 int movable_zone;