2022-10-24 08:23:51

by Baoquan He

Subject: [PATCH 8/8] mm/slub, percpu: correct the calculation of early percpu allocation size

SLUB allocator relies on percpu allocator to initialize its ->cpu_slab
during early boot. For that, the dynamic chunk of percpu which serves
the early allocation need be large enough to satisfy the kmalloc
creation.

However, the current BUILD_BUG_ON() in alloc_kmem_cache_cpus() doesn't
consider the kmalloc array with NR_KMALLOC_TYPES length. Fix that
with correct calculation.

Signed-off-by: Baoquan He <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Pekka Enberg <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Hyeonggon Yoo <[email protected]>
---
mm/slub.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/slub.c b/mm/slub.c
index 157527d7101b..8ac3bb9a122a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4017,7 +4017,8 @@ init_kmem_cache_node(struct kmem_cache_node *n)
static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
{
BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
- KMALLOC_SHIFT_HIGH * sizeof(struct kmem_cache_cpu));
+ NR_KMALLOC_TYPES * KMALLOC_SHIFT_HIGH *
+ sizeof(struct kmem_cache_cpu));

/*
* Must align to double word boundary for the double cmpxchg
--
2.34.1

2022-10-24 16:00:44

by Hyeonggon Yoo

Subject: Re: [PATCH 8/8] mm/slub, percpu: correct the calculation of early percpu allocation size

On Mon, Oct 24, 2022 at 04:14:35PM +0800, Baoquan He wrote:
> SLUB allocator relies on percpu allocator to initialize its ->cpu_slab
> during early boot. For that, the dynamic chunk of percpu which serves
> the early allocation need be large enough to satisfy the kmalloc
> creation.
>
> However, the current BUILD_BUG_ON() in alloc_kmem_cache_cpus() doesn't
> consider the kmalloc array with NR_KMALLOC_TYPES length. Fix that
> with correct calculation.
>
> Signed-off-by: Baoquan He <[email protected]>
> Cc: Christoph Lameter <[email protected]>
> Cc: Pekka Enberg <[email protected]>
> Cc: David Rientjes <[email protected]>
> Cc: Joonsoo Kim <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Vlastimil Babka <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> Cc: Hyeonggon Yoo <[email protected]>
> ---
> mm/slub.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 157527d7101b..8ac3bb9a122a 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4017,7 +4017,8 @@ init_kmem_cache_node(struct kmem_cache_node *n)
> static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
> {
> BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
> - KMALLOC_SHIFT_HIGH * sizeof(struct kmem_cache_cpu));
> + NR_KMALLOC_TYPES * KMALLOC_SHIFT_HIGH *
> + sizeof(struct kmem_cache_cpu));
>
> /*
> * Must align to double word boundary for the double cmpxchg

Looks good to me.

Acked-by: Hyeonggon Yoo <[email protected]>

Thanks!

> --
> 2.34.1
>

--
Thanks,
Hyeonggon

2022-10-24 19:22:20

by Dennis Zhou

Subject: Re: [PATCH 8/8] mm/slub, percpu: correct the calculation of early percpu allocation size

On Mon, Oct 24, 2022 at 04:14:35PM +0800, Baoquan He wrote:
> SLUB allocator relies on percpu allocator to initialize its ->cpu_slab
> during early boot. For that, the dynamic chunk of percpu which serves
> the early allocation need be large enough to satisfy the kmalloc
> creation.
>
> However, the current BUILD_BUG_ON() in alloc_kmem_cache_cpus() doesn't
> consider the kmalloc array with NR_KMALLOC_TYPES length. Fix that
> with correct calculation.
>
> Signed-off-by: Baoquan He <[email protected]>
> Cc: Christoph Lameter <[email protected]>
> Cc: Pekka Enberg <[email protected]>
> Cc: David Rientjes <[email protected]>
> Cc: Joonsoo Kim <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Vlastimil Babka <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> Cc: Hyeonggon Yoo <[email protected]>
> ---
> mm/slub.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 157527d7101b..8ac3bb9a122a 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4017,7 +4017,8 @@ init_kmem_cache_node(struct kmem_cache_node *n)
> static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
> {
> BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
> - KMALLOC_SHIFT_HIGH * sizeof(struct kmem_cache_cpu));
> + NR_KMALLOC_TYPES * KMALLOC_SHIFT_HIGH *
> + sizeof(struct kmem_cache_cpu));
>
> /*
> * Must align to double word boundary for the double cmpxchg
> --
> 2.34.1
>

Acked-by: Dennis Zhou <[email protected]>

Thanks,
Dennis

2022-11-06 21:15:41

by Vlastimil Babka

Subject: Re: [PATCH 8/8] mm/slub, percpu: correct the calculation of early percpu allocation size

On 10/24/22 10:14, Baoquan He wrote:
> SLUB allocator relies on percpu allocator to initialize its ->cpu_slab
> during early boot. For that, the dynamic chunk of percpu which serves
> the early allocation need be large enough to satisfy the kmalloc
> creation.
>
> However, the current BUILD_BUG_ON() in alloc_kmem_cache_cpus() doesn't
> consider the kmalloc array with NR_KMALLOC_TYPES length. Fix that
> with correct calculation.
>
> Signed-off-by: Baoquan He <[email protected]>
> Cc: Christoph Lameter <[email protected]>
> Cc: Pekka Enberg <[email protected]>
> Cc: David Rientjes <[email protected]>
> Cc: Joonsoo Kim <[email protected]>
> Cc: Andrew Morton <[email protected]>
> Cc: Vlastimil Babka <[email protected]>
> Cc: Roman Gushchin <[email protected]>
> Cc: Hyeonggon Yoo <[email protected]>
> ---
> mm/slub.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

As only slub is touched and there's no prerequsities in the previous
patches, I took this to the slab tree, branch
slab/for-6.2/cleanups

Thanks!

>
> diff --git a/mm/slub.c b/mm/slub.c
> index 157527d7101b..8ac3bb9a122a 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -4017,7 +4017,8 @@ init_kmem_cache_node(struct kmem_cache_node *n)
> static inline int alloc_kmem_cache_cpus(struct kmem_cache *s)
> {
> BUILD_BUG_ON(PERCPU_DYNAMIC_EARLY_SIZE <
> - KMALLOC_SHIFT_HIGH * sizeof(struct kmem_cache_cpu));
> + NR_KMALLOC_TYPES * KMALLOC_SHIFT_HIGH *
> + sizeof(struct kmem_cache_cpu));
>
> /*
> * Must align to double word boundary for the double cmpxchg

2022-11-07 05:29:10

by Baoquan He

Subject: Re: [PATCH 8/8] mm/slub, percpu: correct the calculation of early percpu allocation size

On 11/06/22 at 09:56pm, Vlastimil Babka wrote:
> On 10/24/22 10:14, Baoquan He wrote:
> > SLUB allocator relies on percpu allocator to initialize its ->cpu_slab
> > during early boot. For that, the dynamic chunk of percpu which serves
> > the early allocation need be large enough to satisfy the kmalloc
> > creation.
> >
> > However, the current BUILD_BUG_ON() in alloc_kmem_cache_cpus() doesn't
> > consider the kmalloc array with NR_KMALLOC_TYPES length. Fix that
> > with correct calculation.
> >
> > Signed-off-by: Baoquan He <[email protected]>
> > Cc: Christoph Lameter <[email protected]>
> > Cc: Pekka Enberg <[email protected]>
> > Cc: David Rientjes <[email protected]>
> > Cc: Joonsoo Kim <[email protected]>
> > Cc: Andrew Morton <[email protected]>
> > Cc: Vlastimil Babka <[email protected]>
> > Cc: Roman Gushchin <[email protected]>
> > Cc: Hyeonggon Yoo <[email protected]>
> > ---
> > mm/slub.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
>
> As only slub is touched and there's no prerequsities in the previous
> patches, I took this to the slab tree, branch
> slab/for-6.2/cleanups

Yes, it only changes slub code. Thanks for taking it.

I will resend v2 with the left 7 percpu only patches with update.

2022-11-07 07:30:00

by Dennis Zhou

Subject: Re: [PATCH 8/8] mm/slub, percpu: correct the calculation of early percpu allocation size

Hi Baoquan,

On Mon, Nov 07, 2022 at 12:35:56PM +0800, Baoquan He wrote:
> On 11/06/22 at 09:56pm, Vlastimil Babka wrote:
> > On 10/24/22 10:14, Baoquan He wrote:
> > > SLUB allocator relies on percpu allocator to initialize its ->cpu_slab
> > > during early boot. For that, the dynamic chunk of percpu which serves
> > > the early allocation need be large enough to satisfy the kmalloc
> > > creation.
> > >
> > > However, the current BUILD_BUG_ON() in alloc_kmem_cache_cpus() doesn't
> > > consider the kmalloc array with NR_KMALLOC_TYPES length. Fix that
> > > with correct calculation.
> > >
> > > Signed-off-by: Baoquan He <[email protected]>
> > > Cc: Christoph Lameter <[email protected]>
> > > Cc: Pekka Enberg <[email protected]>
> > > Cc: David Rientjes <[email protected]>
> > > Cc: Joonsoo Kim <[email protected]>
> > > Cc: Andrew Morton <[email protected]>
> > > Cc: Vlastimil Babka <[email protected]>
> > > Cc: Roman Gushchin <[email protected]>
> > > Cc: Hyeonggon Yoo <[email protected]>
> > > ---
> > > mm/slub.c | 3 ++-
> > > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > As only slub is touched and there's no prerequsities in the previous
> > patches, I took this to the slab tree, branch
> > slab/for-6.2/cleanups
>
> Yes, it only changes slub code. Thanks for taking it.
>
> I will resend v2 with the left 7 percpu only patches with update.
>
>

Don't worry about resending them, I'll pick them up tomorrow morning.

Thanks,
Dennis

2022-11-07 08:32:13

by Baoquan He

Subject: Re: [PATCH 8/8] mm/slub, percpu: correct the calculation of early percpu allocation size

On 11/06/22 at 11:20pm, Dennis Zhou wrote:
> Hi Baoquan,
>
> On Mon, Nov 07, 2022 at 12:35:56PM +0800, Baoquan He wrote:
> > On 11/06/22 at 09:56pm, Vlastimil Babka wrote:
> > > On 10/24/22 10:14, Baoquan He wrote:
> > > > SLUB allocator relies on percpu allocator to initialize its ->cpu_slab
> > > > during early boot. For that, the dynamic chunk of percpu which serves
> > > > the early allocation need be large enough to satisfy the kmalloc
> > > > creation.
> > > >
> > > > However, the current BUILD_BUG_ON() in alloc_kmem_cache_cpus() doesn't
> > > > consider the kmalloc array with NR_KMALLOC_TYPES length. Fix that
> > > > with correct calculation.
> > > >
> > > > Signed-off-by: Baoquan He <[email protected]>
> > > > Cc: Christoph Lameter <[email protected]>
> > > > Cc: Pekka Enberg <[email protected]>
> > > > Cc: David Rientjes <[email protected]>
> > > > Cc: Joonsoo Kim <[email protected]>
> > > > Cc: Andrew Morton <[email protected]>
> > > > Cc: Vlastimil Babka <[email protected]>
> > > > Cc: Roman Gushchin <[email protected]>
> > > > Cc: Hyeonggon Yoo <[email protected]>
> > > > ---
> > > > mm/slub.c | 3 ++-
> > > > 1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > As only slub is touched and there's no prerequsities in the previous
> > > patches, I took this to the slab tree, branch
> > > slab/for-6.2/cleanups
> >
> > Yes, it only changes slub code. Thanks for taking it.
> >
> > I will resend v2 with the left 7 percpu only patches with update.
> >
> >
>
> Don't worry about resending them, I'll pick them up tomorrow morning.

That's great. Thanks a lot, Dennis.