Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
by grouping pages by mobility, but on tiny systems the extra memory
overhead of separate set of kmalloc-rcl caches will probably be worse,
and mobility grouping likely disabled anyway.
Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
regular ones.
Signed-off-by: Vlastimil Babka <[email protected]>
---
include/linux/slab.h | 4 ++++
mm/slab_common.c | 10 ++++++++--
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 45efc6c553b8..3ce9474c90ab 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -339,7 +339,11 @@ enum kmalloc_cache_type {
#else
KMALLOC_CGROUP,
#endif
+#ifndef CONFIG_SLUB_TINY
KMALLOC_RECLAIM,
+#else
+ KMALLOC_RECLAIM = KMALLOC_NORMAL,
+#endif
#ifdef CONFIG_ZONE_DMA
KMALLOC_DMA,
#endif
diff --git a/mm/slab_common.c b/mm/slab_common.c
index a8cb5de255fc..907d52963806 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -770,10 +770,16 @@ EXPORT_SYMBOL(kmalloc_size_roundup);
#define KMALLOC_CGROUP_NAME(sz)
#endif
+#ifndef CONFIG_SLUB_TINY
+#define KMALLOC_RCL_NAME(sz) .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #sz,
+#else
+#define KMALLOC_RCL_NAME(sz)
+#endif
+
#define INIT_KMALLOC_INFO(__size, __short_size) \
{ \
.name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \
- .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \
+ KMALLOC_RCL_NAME(__short_size) \
KMALLOC_CGROUP_NAME(__short_size) \
KMALLOC_DMA_NAME(__short_size) \
.size = __size, \
@@ -859,7 +865,7 @@ void __init setup_kmalloc_cache_index_table(void)
static void __init
new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
{
- if (type == KMALLOC_RECLAIM) {
+ if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
flags |= SLAB_RECLAIM_ACCOUNT;
} else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
if (mem_cgroup_kmem_disabled()) {
--
2.38.1
On 11/21/22 18:11, Vlastimil Babka wrote:
> Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
> by grouping pages by mobility, but on tiny systems the extra memory
> overhead of separate set of kmalloc-rcl caches will probably be worse,
> and mobility grouping likely disabled anyway.
>
> Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
> regular ones.
>
> Signed-off-by: Vlastimil Babka <[email protected]>
Fixed up in response to lkp report for a MEMCG_KMEM+SLUB_TINY combo:
---8<---
From c1ec0b924850a2863d061f316615d596176f15bb Mon Sep 17 00:00:00 2001
From: Vlastimil Babka <[email protected]>
Date: Tue, 15 Nov 2022 18:19:28 +0100
Subject: [PATCH 06/12] mm, slub: don't create kmalloc-rcl caches with
CONFIG_SLUB_TINY
Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
by grouping pages by mobility, but on tiny systems the extra memory
overhead of separate set of kmalloc-rcl caches will probably be worse,
and mobility grouping likely disabled anyway.
Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
regular ones.
Signed-off-by: Vlastimil Babka <[email protected]>
---
include/linux/slab.h | 9 +++++++--
mm/slab_common.c | 10 ++++++++--
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 45efc6c553b8..ae2d19ec8467 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -336,12 +336,17 @@ enum kmalloc_cache_type {
#endif
#ifndef CONFIG_MEMCG_KMEM
KMALLOC_CGROUP = KMALLOC_NORMAL,
-#else
- KMALLOC_CGROUP,
#endif
+#ifdef CONFIG_SLUB_TINY
+ KMALLOC_RECLAIM = KMALLOC_NORMAL,
+#else
KMALLOC_RECLAIM,
+#endif
#ifdef CONFIG_ZONE_DMA
KMALLOC_DMA,
+#endif
+#ifdef CONFIG_MEMCG_KMEM
+ KMALLOC_CGROUP,
#endif
NR_KMALLOC_TYPES
};
diff --git a/mm/slab_common.c b/mm/slab_common.c
index a8cb5de255fc..907d52963806 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -770,10 +770,16 @@ EXPORT_SYMBOL(kmalloc_size_roundup);
#define KMALLOC_CGROUP_NAME(sz)
#endif
+#ifndef CONFIG_SLUB_TINY
+#define KMALLOC_RCL_NAME(sz) .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #sz,
+#else
+#define KMALLOC_RCL_NAME(sz)
+#endif
+
#define INIT_KMALLOC_INFO(__size, __short_size) \
{ \
.name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \
- .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \
+ KMALLOC_RCL_NAME(__short_size) \
KMALLOC_CGROUP_NAME(__short_size) \
KMALLOC_DMA_NAME(__short_size) \
.size = __size, \
@@ -859,7 +865,7 @@ void __init setup_kmalloc_cache_index_table(void)
static void __init
new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
{
- if (type == KMALLOC_RECLAIM) {
+ if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
flags |= SLAB_RECLAIM_ACCOUNT;
} else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
if (mem_cgroup_kmem_disabled()) {
--
2.38.1
On 11/24/22 13:06, Hyeonggon Yoo wrote:
> On Wed, Nov 23, 2022 at 02:53:43PM +0100, Vlastimil Babka wrote:
>> On 11/21/22 18:11, Vlastimil Babka wrote:
>> > Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
>> > by grouping pages by mobility, but on tiny systems the extra memory
>> > overhead of separate set of kmalloc-rcl caches will probably be worse,
>> > and mobility grouping likely disabled anyway.
>> >
>> > Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
>> > regular ones.
>> >
>> > Signed-off-by: Vlastimil Babka <[email protected]>
>>
>> Fixed up in response to lkp report for a MEMCG_KMEM+SLUB_TINY combo:
>> ---8<---
>> From c1ec0b924850a2863d061f316615d596176f15bb Mon Sep 17 00:00:00 2001
>> From: Vlastimil Babka <[email protected]>
>> Date: Tue, 15 Nov 2022 18:19:28 +0100
>> Subject: [PATCH 06/12] mm, slub: don't create kmalloc-rcl caches with
>> CONFIG_SLUB_TINY
>>
>> Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
>> by grouping pages by mobility, but on tiny systems the extra memory
>> overhead of separate set of kmalloc-rcl caches will probably be worse,
>> and mobility grouping likely disabled anyway.
>>
>> Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
>> regular ones.
>>
>> Signed-off-by: Vlastimil Babka <[email protected]>
>> ---
>> include/linux/slab.h | 9 +++++++--
>> mm/slab_common.c | 10 ++++++++--
>> 2 files changed, 15 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/linux/slab.h b/include/linux/slab.h
>> index 45efc6c553b8..ae2d19ec8467 100644
>> --- a/include/linux/slab.h
>> +++ b/include/linux/slab.h
>> @@ -336,12 +336,17 @@ enum kmalloc_cache_type {
>> #endif
>> #ifndef CONFIG_MEMCG_KMEM
>> KMALLOC_CGROUP = KMALLOC_NORMAL,
>> -#else
>> - KMALLOC_CGROUP,
>> #endif
>> +#ifdef CONFIG_SLUB_TINY
>> + KMALLOC_RECLAIM = KMALLOC_NORMAL,
>> +#else
>> KMALLOC_RECLAIM,
>> +#endif
>> #ifdef CONFIG_ZONE_DMA
>> KMALLOC_DMA,
>> +#endif
>> +#ifdef CONFIG_MEMCG_KMEM
>> + KMALLOC_CGROUP,
>> #endif
>> NR_KMALLOC_TYPES
>> };
>
> Can you please elaborate what the lkp report was about
> and how you fixed it? I'm not getting what the problem of previous
> version is.
Report here:
https://lore.kernel.org/all/[email protected]/
Problem is that if the preprocessing results in e.g.
KMALLOC_NORMAL = 0,
KMALLOC_DMA = KMALLOC_NORMAL
KMALLOC_CGROUP,
KMALLOC_RECLAIM = KMALLOC_NORMAL,
NR_KMALLOC_TYPES
then NR_KMALLOC_TYPES is not 2, but 1, because the enum's internal counter
got reset to 0 by KMALLOC_RECLAIM = KMALLOC_NORMAL. A common gotcha :/
On Wed, Nov 23, 2022 at 02:53:43PM +0100, Vlastimil Babka wrote:
> On 11/21/22 18:11, Vlastimil Babka wrote:
> > Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
> > by grouping pages by mobility, but on tiny systems the extra memory
> > overhead of separate set of kmalloc-rcl caches will probably be worse,
> > and mobility grouping likely disabled anyway.
> >
> > Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
> > regular ones.
> >
> > Signed-off-by: Vlastimil Babka <[email protected]>
>
> Fixed up in response to lkp report for a MEMCG_KMEM+SLUB_TINY combo:
> ---8<---
> From c1ec0b924850a2863d061f316615d596176f15bb Mon Sep 17 00:00:00 2001
> From: Vlastimil Babka <[email protected]>
> Date: Tue, 15 Nov 2022 18:19:28 +0100
> Subject: [PATCH 06/12] mm, slub: don't create kmalloc-rcl caches with
> CONFIG_SLUB_TINY
>
> Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
> by grouping pages by mobility, but on tiny systems the extra memory
> overhead of separate set of kmalloc-rcl caches will probably be worse,
> and mobility grouping likely disabled anyway.
>
> Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
> regular ones.
>
> Signed-off-by: Vlastimil Babka <[email protected]>
> ---
> include/linux/slab.h | 9 +++++++--
> mm/slab_common.c | 10 ++++++++--
> 2 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 45efc6c553b8..ae2d19ec8467 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -336,12 +336,17 @@ enum kmalloc_cache_type {
> #endif
> #ifndef CONFIG_MEMCG_KMEM
> KMALLOC_CGROUP = KMALLOC_NORMAL,
> -#else
> - KMALLOC_CGROUP,
> #endif
> +#ifdef CONFIG_SLUB_TINY
> + KMALLOC_RECLAIM = KMALLOC_NORMAL,
> +#else
> KMALLOC_RECLAIM,
> +#endif
> #ifdef CONFIG_ZONE_DMA
> KMALLOC_DMA,
> +#endif
> +#ifdef CONFIG_MEMCG_KMEM
> + KMALLOC_CGROUP,
> #endif
> NR_KMALLOC_TYPES
> };
Can you please elaborate what the lkp report was about
and how you fixed it? I'm not getting what the problem of previous
version is.
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index a8cb5de255fc..907d52963806 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -770,10 +770,16 @@ EXPORT_SYMBOL(kmalloc_size_roundup);
> #define KMALLOC_CGROUP_NAME(sz)
> #endif
>
> +#ifndef CONFIG_SLUB_TINY
> +#define KMALLOC_RCL_NAME(sz) .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #sz,
> +#else
> +#define KMALLOC_RCL_NAME(sz)
> +#endif
> +
> #define INIT_KMALLOC_INFO(__size, __short_size) \
> { \
> .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \
> - .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \
> + KMALLOC_RCL_NAME(__short_size) \
> KMALLOC_CGROUP_NAME(__short_size) \
> KMALLOC_DMA_NAME(__short_size) \
> .size = __size, \
> @@ -859,7 +865,7 @@ void __init setup_kmalloc_cache_index_table(void)
> static void __init
> new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
> {
> - if (type == KMALLOC_RECLAIM) {
> + if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
> flags |= SLAB_RECLAIM_ACCOUNT;
> } else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
> if (mem_cgroup_kmem_disabled()) {
> --
> 2.38.1
>
Otherwise looks fine to me.
--
Thanks,
Hyeonggon
On Thu, Nov 24, 2022 at 01:12:13PM +0100, Vlastimil Babka wrote:
> On 11/24/22 13:06, Hyeonggon Yoo wrote:
> > On Wed, Nov 23, 2022 at 02:53:43PM +0100, Vlastimil Babka wrote:
> >> On 11/21/22 18:11, Vlastimil Babka wrote:
> >> > Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
> >> > by grouping pages by mobility, but on tiny systems the extra memory
> >> > overhead of separate set of kmalloc-rcl caches will probably be worse,
> >> > and mobility grouping likely disabled anyway.
> >> >
> >> > Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
> >> > regular ones.
> >> >
> >> > Signed-off-by: Vlastimil Babka <[email protected]>
> >>
> >> Fixed up in response to lkp report for a MEMCG_KMEM+SLUB_TINY combo:
> >> ---8<---
> >> From c1ec0b924850a2863d061f316615d596176f15bb Mon Sep 17 00:00:00 2001
> >> From: Vlastimil Babka <[email protected]>
> >> Date: Tue, 15 Nov 2022 18:19:28 +0100
> >> Subject: [PATCH 06/12] mm, slub: don't create kmalloc-rcl caches with
> >> CONFIG_SLUB_TINY
> >>
> >> Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
> >> by grouping pages by mobility, but on tiny systems the extra memory
> >> overhead of separate set of kmalloc-rcl caches will probably be worse,
> >> and mobility grouping likely disabled anyway.
> >>
> >> Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
> >> regular ones.
> >>
> >> Signed-off-by: Vlastimil Babka <[email protected]>
> >> ---
> >> include/linux/slab.h | 9 +++++++--
> >> mm/slab_common.c | 10 ++++++++--
> >> 2 files changed, 15 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/include/linux/slab.h b/include/linux/slab.h
> >> index 45efc6c553b8..ae2d19ec8467 100644
> >> --- a/include/linux/slab.h
> >> +++ b/include/linux/slab.h
> >> @@ -336,12 +336,17 @@ enum kmalloc_cache_type {
> >> #endif
> >> #ifndef CONFIG_MEMCG_KMEM
> >> KMALLOC_CGROUP = KMALLOC_NORMAL,
> >> -#else
> >> - KMALLOC_CGROUP,
> >> #endif
> >> +#ifdef CONFIG_SLUB_TINY
> >> + KMALLOC_RECLAIM = KMALLOC_NORMAL,
> >> +#else
> >> KMALLOC_RECLAIM,
> >> +#endif
> >> #ifdef CONFIG_ZONE_DMA
> >> KMALLOC_DMA,
> >> +#endif
> >> +#ifdef CONFIG_MEMCG_KMEM
> >> + KMALLOC_CGROUP,
> >> #endif
> >> NR_KMALLOC_TYPES
> >> };
> >
> > Can you please elaborate what the lkp report was about
> > and how you fixed it? I'm not getting what the problem of previous
> > version is.
>
> Report here:
> https://lore.kernel.org/all/[email protected]/
>
> Problem is that if the preprocessing results in e.g.
> KMALLOC_NORMAL = 0,
> KMALLOC_DMA = KMALLOC_NORMAL
> KMALLOC_CGROUP,
> KMALLOC_RECLAIM = KMALLOC_NORMAL,
> NR_KMALLOC_TYPES
>
> then NR_KMALLOC_TYPES is not 2, but 1, because the enum's internal counter
> got reset to 0 by KMALLOC_RECLAIM = KMALLOC_NORMAL. A common gotcha :/
Thanks for quick and kind explanation :)
That was easy to be missed.
--
Thanks,
Hyeonggon
On Wed, Nov 23, 2022 at 02:53:43PM +0100, Vlastimil Babka wrote:
> On 11/21/22 18:11, Vlastimil Babka wrote:
> > Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
> > by grouping pages by mobility, but on tiny systems the extra memory
> > overhead of separate set of kmalloc-rcl caches will probably be worse,
> > and mobility grouping likely disabled anyway.
> >
> > Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
> > regular ones.
> >
> > Signed-off-by: Vlastimil Babka <[email protected]>
>
> Fixed up in response to lkp report for a MEMCG_KMEM+SLUB_TINY combo:
> ---8<---
> From c1ec0b924850a2863d061f316615d596176f15bb Mon Sep 17 00:00:00 2001
> From: Vlastimil Babka <[email protected]>
> Date: Tue, 15 Nov 2022 18:19:28 +0100
> Subject: [PATCH 06/12] mm, slub: don't create kmalloc-rcl caches with
> CONFIG_SLUB_TINY
>
> Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation
> by grouping pages by mobility, but on tiny systems the extra memory
> overhead of separate set of kmalloc-rcl caches will probably be worse,
> and mobility grouping likely disabled anyway.
>
> Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the
> regular ones.
>
> Signed-off-by: Vlastimil Babka <[email protected]>
> ---
> include/linux/slab.h | 9 +++++++--
> mm/slab_common.c | 10 ++++++++--
> 2 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 45efc6c553b8..ae2d19ec8467 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -336,12 +336,17 @@ enum kmalloc_cache_type {
> #endif
> #ifndef CONFIG_MEMCG_KMEM
> KMALLOC_CGROUP = KMALLOC_NORMAL,
> -#else
> - KMALLOC_CGROUP,
> #endif
> +#ifdef CONFIG_SLUB_TINY
> + KMALLOC_RECLAIM = KMALLOC_NORMAL,
> +#else
> KMALLOC_RECLAIM,
> +#endif
> #ifdef CONFIG_ZONE_DMA
> KMALLOC_DMA,
> +#endif
> +#ifdef CONFIG_MEMCG_KMEM
> + KMALLOC_CGROUP,
> #endif
> NR_KMALLOC_TYPES
> };
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index a8cb5de255fc..907d52963806 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -770,10 +770,16 @@ EXPORT_SYMBOL(kmalloc_size_roundup);
> #define KMALLOC_CGROUP_NAME(sz)
> #endif
>
> +#ifndef CONFIG_SLUB_TINY
> +#define KMALLOC_RCL_NAME(sz) .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #sz,
> +#else
> +#define KMALLOC_RCL_NAME(sz)
> +#endif
> +
> #define INIT_KMALLOC_INFO(__size, __short_size) \
> { \
> .name[KMALLOC_NORMAL] = "kmalloc-" #__short_size, \
> - .name[KMALLOC_RECLAIM] = "kmalloc-rcl-" #__short_size, \
> + KMALLOC_RCL_NAME(__short_size) \
> KMALLOC_CGROUP_NAME(__short_size) \
> KMALLOC_DMA_NAME(__short_size) \
> .size = __size, \
> @@ -859,7 +865,7 @@ void __init setup_kmalloc_cache_index_table(void)
> static void __init
> new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
> {
> - if (type == KMALLOC_RECLAIM) {
> + if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
for consistency this can be:
if (IS_ENABLED(CONFIG_SLUB_TINY) && (type == KMALLOC_RECLAIM)) {
But yeah, it's not a big deal.
> flags |= SLAB_RECLAIM_ACCOUNT;
> } else if (IS_ENABLED(CONFIG_MEMCG_KMEM) && (type == KMALLOC_CGROUP)) {
> if (mem_cgroup_kmem_disabled()) {
> --
> 2.38.1
>
For either case:
Looks good to me.
Reviewed-by: Hyeonggon Yoo <[email protected]>
--
Thanks,
Hyeonggon
On Thu, Nov 24, 2022 at 10:23:51PM +0900, Hyeonggon Yoo wrote:
> > @@ -859,7 +865,7 @@ void __init setup_kmalloc_cache_index_table(void)
> > static void __init
> > new_kmalloc_cache(int idx, enum kmalloc_cache_type type, slab_flags_t flags)
> > {
> > - if (type == KMALLOC_RECLAIM) {
> > + if ((KMALLOC_RECLAIM != KMALLOC_NORMAL) && (type == KMALLOC_RECLAIM)) {
>
> for consistency this can be:
> if (IS_ENABLED(CONFIG_SLUB_TINY) && (type == KMALLOC_RECLAIM)) {
>
My finger slipped :)
I mean:
if (!IS_ENABLED(CONFIG_SLUB_TINY) && (type == KMALLOC_RECLAIM)) {
--
Thanks,
Hyeonggon