From: Ma Wupeng <[email protected]>
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 <[email protected]>
Acked-by: Ard Biesheuvel <[email protected]>
---
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;
+
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
On Tue, 14 Jun 2022 at 12:20, Baoquan He <[email protected]> wrote:
>
> On 06/14/22 at 05:21pm, Wupeng Ma wrote:
> > From: Ma Wupeng <[email protected]>
> >
> > 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 <[email protected]>
> > Acked-by: Ard Biesheuvel <[email protected]>
> > ---
> > 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.
On 06/14/22 at 05:21pm, Wupeng Ma wrote:
> From: Ma Wupeng <[email protected]>
>
> 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 <[email protected]>
> Acked-by: Ard Biesheuvel <[email protected]>
> ---
> 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
>
>
On 06/14/22 at 12:27pm, Ard Biesheuvel wrote:
> On Tue, 14 Jun 2022 at 12:20, Baoquan He <[email protected]> wrote:
> >
> > On 06/14/22 at 05:21pm, Wupeng Ma wrote:
> > > From: Ma Wupeng <[email protected]>
> > >
> > > 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 <[email protected]>
> > > Acked-by: Ard Biesheuvel <[email protected]>
> > > ---
> > > 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.
>