2023-11-22 04:36:39

by Baoquan He

[permalink] [raw]
Subject: [PATCH] mm/page.c: move mem_init_print_info() to later place

Currently if CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, only part of
pages are initialized and added into buddy allocator at early stage. Then
the system memory information printed by mem_init_print_info() is
incorrect. The snippets of boot log are pasted here:
-----------------------------------------------------------------------
[ 0.059606] mem auto-init: stack:all(zero), heap alloc:off, heap free:off
[ 0.059622] software IO TLB: area num 64.
[ 0.143887] Memory: 1767888K/133954872K available (20480K kernel code, 3284K rwdata, 8972K rodata, 4572K init, 4916K bss, 2529756K reserved, 0K cma-reserved)
[ 0.145111] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=64, Nodes=2
---------------------------------------------------------------------------

Here, move mem_init_print_info() to later place until page init is
finished. After the fix, the printed memory information is like this:
-------------------------------------------------------------------------
[ +0.001002] smpboot: Total of 64 processors activated (293724.92 BogoMIPS)
[ +0.050086] node 0 deferred pages initialised in 45ms
[ +0.007309] node 1 deferred pages initialised in 53ms
[ 4.035449] Memory: 131272772K/133954872K available (20480K kernel code, 3284K rwdata, 8972K rodata, 4572K init, 4916K bss, 2529700K reserved, 0K cma-reserved)
[ +0.015995] devtmpfs: initialized
[ +0.003943] x86/mm: Memory block size: 2048MB
-------------------------------------------------------------------------

Signed-off-by: Baoquan He <[email protected]>
---
include/linux/gfp.h | 1 +
init/main.c | 1 +
mm/mm_init.c | 3 +--
3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index de292a007138..2d69fa59b489 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -335,6 +335,7 @@ void drain_local_pages(struct zone *zone);

void page_alloc_init_late(void);
void setup_pcp_cacheinfo(void);
+void mem_init_print_info(void);

/*
* gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
diff --git a/init/main.c b/init/main.c
index e24b0780fdff..88f238a478a1 100644
--- a/init/main.c
+++ b/init/main.c
@@ -1547,6 +1547,7 @@ static noinline void __init kernel_init_freeable(void)
workqueue_init_topology();
padata_init();
page_alloc_init_late();
+ mem_init_print_info();

do_basic_setup();

diff --git a/mm/mm_init.c b/mm/mm_init.c
index 077bfe393b5e..d08f7c7f75f1 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -2703,7 +2703,7 @@ static void __init report_meminit(void)
pr_info("mem auto-init: clearing system memory may take some time...\n");
}

-static void __init mem_init_print_info(void)
+void __init mem_init_print_info(void)
{
unsigned long physpages, codesize, datasize, rosize, bss_size;
unsigned long init_code_size, init_data_size;
@@ -2774,7 +2774,6 @@ void __init mm_core_init(void)
kmsan_init_shadow();
stack_depot_early_init();
mem_init();
- mem_init_print_info();
kmem_cache_init();
/*
* page_owner must be initialized after buddy is ready, and also after
--
2.41.0


2023-11-22 15:08:48

by Mike Rapoport

[permalink] [raw]
Subject: Re: [PATCH] mm/page.c: move mem_init_print_info() to later place

Hi Baoquan,


On Wed, Nov 22, 2023 at 12:35:50PM +0800, Baoquan He wrote:

> Subject: [PATCH] mm/page.c: move mem_init_print_info() to later place

We don't have mm/page.c,

> Currently if CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, only part of
> pages are initialized and added into buddy allocator at early stage. Then
> the system memory information printed by mem_init_print_info() is
> incorrect. The snippets of boot log are pasted here:
> -----------------------------------------------------------------------
> [ 0.059606] mem auto-init: stack:all(zero), heap alloc:off, heap free:off
> [ 0.059622] software IO TLB: area num 64.
> [ 0.143887] Memory: 1767888K/133954872K available (20480K kernel code, 3284K rwdata, 8972K rodata, 4572K init, 4916K bss, 2529756K reserved, 0K cma-reserved)
> [ 0.145111] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=64, Nodes=2
> ---------------------------------------------------------------------------

At this point only the pages that were initialized and free are available.
The message does not reflect that large part of memory is still not initialized,
but it's not wrong.

> Here, move mem_init_print_info() to later place until page init is
> finished. After the fix, the printed memory information is like this:
> -------------------------------------------------------------------------
> [ +0.001002] smpboot: Total of 64 processors activated (293724.92 BogoMIPS)
> [ +0.050086] node 0 deferred pages initialised in 45ms
> [ +0.007309] node 1 deferred pages initialised in 53ms
> [ 4.035449] Memory: 131272772K/133954872K available (20480K kernel code, 3284K rwdata, 8972K rodata, 4572K init, 4916K bss, 2529700K reserved, 0K cma-reserved)
> [ +0.015995] devtmpfs: initialized
> [ +0.003943] x86/mm: Memory block size: 2048MB
> -------------------------------------------------------------------------

If we print this message that late, some of the memory will be allocated
from buddy and it maybe confusing.

I suggest to print how much memory is not yet initialized and leave
mem_init_print_info() where it is now.

> Signed-off-by: Baoquan He <[email protected]>
> ---
> include/linux/gfp.h | 1 +
> init/main.c | 1 +
> mm/mm_init.c | 3 +--
> 3 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> index de292a007138..2d69fa59b489 100644
> --- a/include/linux/gfp.h
> +++ b/include/linux/gfp.h
> @@ -335,6 +335,7 @@ void drain_local_pages(struct zone *zone);
>
> void page_alloc_init_late(void);
> void setup_pcp_cacheinfo(void);
> +void mem_init_print_info(void);
>
> /*
> * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
> diff --git a/init/main.c b/init/main.c
> index e24b0780fdff..88f238a478a1 100644
> --- a/init/main.c
> +++ b/init/main.c
> @@ -1547,6 +1547,7 @@ static noinline void __init kernel_init_freeable(void)
> workqueue_init_topology();
> padata_init();
> page_alloc_init_late();
> + mem_init_print_info();

No need to make mem_init_print_info() global and call it from main.c, you
can call it from page_alloc_init_late().

> do_basic_setup();
>
> diff --git a/mm/mm_init.c b/mm/mm_init.c
> index 077bfe393b5e..d08f7c7f75f1 100644
> --- a/mm/mm_init.c
> +++ b/mm/mm_init.c
> @@ -2703,7 +2703,7 @@ static void __init report_meminit(void)
> pr_info("mem auto-init: clearing system memory may take some time...\n");
> }
>
> -static void __init mem_init_print_info(void)
> +void __init mem_init_print_info(void)
> {
> unsigned long physpages, codesize, datasize, rosize, bss_size;
> unsigned long init_code_size, init_data_size;
> @@ -2774,7 +2774,6 @@ void __init mm_core_init(void)
> kmsan_init_shadow();
> stack_depot_early_init();
> mem_init();
> - mem_init_print_info();
> kmem_cache_init();
> /*
> * page_owner must be initialized after buddy is ready, and also after
> --
> 2.41.0
>

--
Sincerely yours,
Mike.

2023-11-24 07:34:43

by Baoquan He

[permalink] [raw]
Subject: Re: [PATCH] mm/page.c: move mem_init_print_info() to later place

On 11/22/23 at 05:08pm, Mike Rapoport wrote:
> Hi Baoquan,
>
>
> On Wed, Nov 22, 2023 at 12:35:50PM +0800, Baoquan He wrote:
>
> > Subject: [PATCH] mm/page.c: move mem_init_print_info() to later place
>
> We don't have mm/page.c,

Thanks for reviewing.

Yes, this was queued in my local branch long time ago, I forgot to
update the file name.

>
> > Currently if CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, only part of
> > pages are initialized and added into buddy allocator at early stage. Then
> > the system memory information printed by mem_init_print_info() is
> > incorrect. The snippets of boot log are pasted here:
> > -----------------------------------------------------------------------
> > [ 0.059606] mem auto-init: stack:all(zero), heap alloc:off, heap free:off
> > [ 0.059622] software IO TLB: area num 64.
> > [ 0.143887] Memory: 1767888K/133954872K available (20480K kernel code, 3284K rwdata, 8972K rodata, 4572K init, 4916K bss, 2529756K reserved, 0K cma-reserved)
> > [ 0.145111] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=64, Nodes=2
> > ---------------------------------------------------------------------------
>
> At this point only the pages that were initialized and free are available.
> The message does not reflect that large part of memory is still not initialized,
> but it's not wrong.

Agree. I noticed this because I often need check the memory init and
memory size during kernel bootup. The current message gives people a
shock at first glance because it looks like a huge reserved memory
existing in system.

>
> > Here, move mem_init_print_info() to later place until page init is
> > finished. After the fix, the printed memory information is like this:
> > -------------------------------------------------------------------------
> > [ +0.001002] smpboot: Total of 64 processors activated (293724.92 BogoMIPS)
> > [ +0.050086] node 0 deferred pages initialised in 45ms
> > [ +0.007309] node 1 deferred pages initialised in 53ms
> > [ 4.035449] Memory: 131272772K/133954872K available (20480K kernel code, 3284K rwdata, 8972K rodata, 4572K init, 4916K bss, 2529700K reserved, 0K cma-reserved)
> > [ +0.015995] devtmpfs: initialized
> > [ +0.003943] x86/mm: Memory block size: 2048MB
> > -------------------------------------------------------------------------
>
> If we print this message that late, some of the memory will be allocated
> from buddy and it maybe confusing.

that's true.

>
> I suggest to print how much memory is not yet initialized and leave
> mem_init_print_info() where it is now.

Sounds great to me, will work out a new version as suggested.

>
> > Signed-off-by: Baoquan He <[email protected]>
> > ---
> > include/linux/gfp.h | 1 +
> > init/main.c | 1 +
> > mm/mm_init.c | 3 +--
> > 3 files changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/include/linux/gfp.h b/include/linux/gfp.h
> > index de292a007138..2d69fa59b489 100644
> > --- a/include/linux/gfp.h
> > +++ b/include/linux/gfp.h
> > @@ -335,6 +335,7 @@ void drain_local_pages(struct zone *zone);
> >
> > void page_alloc_init_late(void);
> > void setup_pcp_cacheinfo(void);
> > +void mem_init_print_info(void);
> >
> > /*
> > * gfp_allowed_mask is set to GFP_BOOT_MASK during early boot to restrict what
> > diff --git a/init/main.c b/init/main.c
> > index e24b0780fdff..88f238a478a1 100644
> > --- a/init/main.c
> > +++ b/init/main.c
> > @@ -1547,6 +1547,7 @@ static noinline void __init kernel_init_freeable(void)
> > workqueue_init_topology();
> > padata_init();
> > page_alloc_init_late();
> > + mem_init_print_info();
>
> No need to make mem_init_print_info() global and call it from main.c, you
> can call it from page_alloc_init_late().

Agree, that's much better if we take that way.

>
> > do_basic_setup();
> >
> > diff --git a/mm/mm_init.c b/mm/mm_init.c
> > index 077bfe393b5e..d08f7c7f75f1 100644
> > --- a/mm/mm_init.c
> > +++ b/mm/mm_init.c
> > @@ -2703,7 +2703,7 @@ static void __init report_meminit(void)
> > pr_info("mem auto-init: clearing system memory may take some time...\n");
> > }
> >
> > -static void __init mem_init_print_info(void)
> > +void __init mem_init_print_info(void)
> > {
> > unsigned long physpages, codesize, datasize, rosize, bss_size;
> > unsigned long init_code_size, init_data_size;
> > @@ -2774,7 +2774,6 @@ void __init mm_core_init(void)
> > kmsan_init_shadow();
> > stack_depot_early_init();
> > mem_init();
> > - mem_init_print_info();
> > kmem_cache_init();
> > /*
> > * page_owner must be initialized after buddy is ready, and also after
> > --
> > 2.41.0
> >
>
> --
> Sincerely yours,
> Mike.
>