Hi,
We are observing a performance regression on one of our arm64 boards.
We tracked it down to the linux-6.6.y commit ada8d7fa0ad4 ("sched/cpufreq:
Rework schedutil governor performance estimation").
UI speedometer benchmark:
w/commit: 395 +/-38
w/o commit: 439 +/-14
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 0d6c356dd6547adac2b06b461528e3573f52d953
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112032-parted-progeny-cd9e@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 0d6c356dd6547adac2b06b461528e3573f52d953 Mon Sep 17 00:00:00 2001
From: "Isaac J. Manjarres" <isaacmanjarres(a)google.com>
Date: Tue, 28 Oct 2025 12:10:12 -0700
Subject: [PATCH] mm/mm_init: fix hash table order logging in
alloc_large_system_hash()
When emitting the order of the allocation for a hash table,
alloc_large_system_hash() unconditionally subtracts PAGE_SHIFT from log
base 2 of the allocation size. This is not correct if the allocation size
is smaller than a page, and yields a negative value for the order as seen
below:
TCP established hash table entries: 32 (order: -4, 256 bytes, linear) TCP
bind hash table entries: 32 (order: -2, 1024 bytes, linear)
Use get_order() to compute the order when emitting the hash table
information to correctly handle cases where the allocation size is smaller
than a page:
TCP established hash table entries: 32 (order: 0, 256 bytes, linear) TCP
bind hash table entries: 32 (order: 0, 1024 bytes, linear)
Link: https://lkml.kernel.org/r/20251028191020.413002-1-isaacmanjarres@google.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Isaac J. Manjarres <isaacmanjarres(a)google.com>
Reviewed-by: Mike Rapoport (Microsoft) <rppt(a)kernel.org>
Reviewed-by: David Hildenbrand <david(a)redhat.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 3db2dea7db4c..7712d887b696 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -2469,7 +2469,7 @@ void *__init alloc_large_system_hash(const char *tablename,
panic("Failed to allocate %s hash table\n", tablename);
pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
- tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size,
+ tablename, 1UL << log2qty, get_order(size), size,
virt ? (huge ? "vmalloc hugepage" : "vmalloc") : "linear");
if (_hash_shift)
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 49c8d2c1f94cc2f4d1a108530d7ba52614b874c2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112011-candied-surrogate-885f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 49c8d2c1f94cc2f4d1a108530d7ba52614b874c2 Mon Sep 17 00:00:00 2001
From: Breno Leitao <leitao(a)debian.org>
Date: Fri, 7 Nov 2025 06:03:37 -0800
Subject: [PATCH] net: netpoll: fix incorrect refcount handling causing
incorrect cleanup
commit efa95b01da18 ("netpoll: fix use after free") incorrectly
ignored the refcount and prematurely set dev->npinfo to NULL during
netpoll cleanup, leading to improper behavior and memory leaks.
Scenario causing lack of proper cleanup:
1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is
allocated, and refcnt = 1
- Keep in mind that npinfo is shared among all netpoll instances. In
this case, there is just one.
2) Another netpoll is also associated with the same NIC and
npinfo->refcnt += 1.
- Now dev->npinfo->refcnt = 2;
- There is just one npinfo associated to the netdev.
3) When the first netpolls goes to clean up:
- The first cleanup succeeds and clears np->dev->npinfo, ignoring
refcnt.
- It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);`
- Set dev->npinfo = NULL, without proper cleanup
- No ->ndo_netpoll_cleanup() is either called
4) Now the second target tries to clean up
- The second cleanup fails because np->dev->npinfo is already NULL.
* In this case, ops->ndo_netpoll_cleanup() was never called, and
the skb pool is not cleaned as well (for the second netpoll
instance)
- This leaks npinfo and skbpool skbs, which is clearly reported by
kmemleak.
Revert commit efa95b01da18 ("netpoll: fix use after free") and adds
clarifying comments emphasizing that npinfo cleanup should only happen
once the refcount reaches zero, ensuring stable and correct netpoll
behavior.
Cc: <stable(a)vger.kernel.org> # 3.17.x
Cc: Jay Vosburgh <jv(a)jvosburgh.net>
Fixes: efa95b01da18 ("netpoll: fix use after free")
Signed-off-by: Breno Leitao <leitao(a)debian.org>
Reviewed-by: Simon Horman <horms(a)kernel.org>
Link: https://patch.msgid.link/20251107-netconsole_torture-v10-1-749227b55f63@deb…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index c85f740065fc..331764845e8f 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -811,6 +811,10 @@ static void __netpoll_cleanup(struct netpoll *np)
if (!npinfo)
return;
+ /* At this point, there is a single npinfo instance per netdevice, and
+ * its refcnt tracks how many netpoll structures are linked to it. We
+ * only perform npinfo cleanup when the refcnt decrements to zero.
+ */
if (refcount_dec_and_test(&npinfo->refcnt)) {
const struct net_device_ops *ops;
@@ -820,8 +824,7 @@ static void __netpoll_cleanup(struct netpoll *np)
RCU_INIT_POINTER(np->dev->npinfo, NULL);
call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
- } else
- RCU_INIT_POINTER(np->dev->npinfo, NULL);
+ }
skb_pool_flush(np);
}
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 49c8d2c1f94cc2f4d1a108530d7ba52614b874c2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112010-elm-hardwired-dce7@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 49c8d2c1f94cc2f4d1a108530d7ba52614b874c2 Mon Sep 17 00:00:00 2001
From: Breno Leitao <leitao(a)debian.org>
Date: Fri, 7 Nov 2025 06:03:37 -0800
Subject: [PATCH] net: netpoll: fix incorrect refcount handling causing
incorrect cleanup
commit efa95b01da18 ("netpoll: fix use after free") incorrectly
ignored the refcount and prematurely set dev->npinfo to NULL during
netpoll cleanup, leading to improper behavior and memory leaks.
Scenario causing lack of proper cleanup:
1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is
allocated, and refcnt = 1
- Keep in mind that npinfo is shared among all netpoll instances. In
this case, there is just one.
2) Another netpoll is also associated with the same NIC and
npinfo->refcnt += 1.
- Now dev->npinfo->refcnt = 2;
- There is just one npinfo associated to the netdev.
3) When the first netpolls goes to clean up:
- The first cleanup succeeds and clears np->dev->npinfo, ignoring
refcnt.
- It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);`
- Set dev->npinfo = NULL, without proper cleanup
- No ->ndo_netpoll_cleanup() is either called
4) Now the second target tries to clean up
- The second cleanup fails because np->dev->npinfo is already NULL.
* In this case, ops->ndo_netpoll_cleanup() was never called, and
the skb pool is not cleaned as well (for the second netpoll
instance)
- This leaks npinfo and skbpool skbs, which is clearly reported by
kmemleak.
Revert commit efa95b01da18 ("netpoll: fix use after free") and adds
clarifying comments emphasizing that npinfo cleanup should only happen
once the refcount reaches zero, ensuring stable and correct netpoll
behavior.
Cc: <stable(a)vger.kernel.org> # 3.17.x
Cc: Jay Vosburgh <jv(a)jvosburgh.net>
Fixes: efa95b01da18 ("netpoll: fix use after free")
Signed-off-by: Breno Leitao <leitao(a)debian.org>
Reviewed-by: Simon Horman <horms(a)kernel.org>
Link: https://patch.msgid.link/20251107-netconsole_torture-v10-1-749227b55f63@deb…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index c85f740065fc..331764845e8f 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -811,6 +811,10 @@ static void __netpoll_cleanup(struct netpoll *np)
if (!npinfo)
return;
+ /* At this point, there is a single npinfo instance per netdevice, and
+ * its refcnt tracks how many netpoll structures are linked to it. We
+ * only perform npinfo cleanup when the refcnt decrements to zero.
+ */
if (refcount_dec_and_test(&npinfo->refcnt)) {
const struct net_device_ops *ops;
@@ -820,8 +824,7 @@ static void __netpoll_cleanup(struct netpoll *np)
RCU_INIT_POINTER(np->dev->npinfo, NULL);
call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
- } else
- RCU_INIT_POINTER(np->dev->npinfo, NULL);
+ }
skb_pool_flush(np);
}
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 49c8d2c1f94cc2f4d1a108530d7ba52614b874c2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112008-harddisk-preseason-c83e@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 49c8d2c1f94cc2f4d1a108530d7ba52614b874c2 Mon Sep 17 00:00:00 2001
From: Breno Leitao <leitao(a)debian.org>
Date: Fri, 7 Nov 2025 06:03:37 -0800
Subject: [PATCH] net: netpoll: fix incorrect refcount handling causing
incorrect cleanup
commit efa95b01da18 ("netpoll: fix use after free") incorrectly
ignored the refcount and prematurely set dev->npinfo to NULL during
netpoll cleanup, leading to improper behavior and memory leaks.
Scenario causing lack of proper cleanup:
1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is
allocated, and refcnt = 1
- Keep in mind that npinfo is shared among all netpoll instances. In
this case, there is just one.
2) Another netpoll is also associated with the same NIC and
npinfo->refcnt += 1.
- Now dev->npinfo->refcnt = 2;
- There is just one npinfo associated to the netdev.
3) When the first netpolls goes to clean up:
- The first cleanup succeeds and clears np->dev->npinfo, ignoring
refcnt.
- It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);`
- Set dev->npinfo = NULL, without proper cleanup
- No ->ndo_netpoll_cleanup() is either called
4) Now the second target tries to clean up
- The second cleanup fails because np->dev->npinfo is already NULL.
* In this case, ops->ndo_netpoll_cleanup() was never called, and
the skb pool is not cleaned as well (for the second netpoll
instance)
- This leaks npinfo and skbpool skbs, which is clearly reported by
kmemleak.
Revert commit efa95b01da18 ("netpoll: fix use after free") and adds
clarifying comments emphasizing that npinfo cleanup should only happen
once the refcount reaches zero, ensuring stable and correct netpoll
behavior.
Cc: <stable(a)vger.kernel.org> # 3.17.x
Cc: Jay Vosburgh <jv(a)jvosburgh.net>
Fixes: efa95b01da18 ("netpoll: fix use after free")
Signed-off-by: Breno Leitao <leitao(a)debian.org>
Reviewed-by: Simon Horman <horms(a)kernel.org>
Link: https://patch.msgid.link/20251107-netconsole_torture-v10-1-749227b55f63@deb…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index c85f740065fc..331764845e8f 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -811,6 +811,10 @@ static void __netpoll_cleanup(struct netpoll *np)
if (!npinfo)
return;
+ /* At this point, there is a single npinfo instance per netdevice, and
+ * its refcnt tracks how many netpoll structures are linked to it. We
+ * only perform npinfo cleanup when the refcnt decrements to zero.
+ */
if (refcount_dec_and_test(&npinfo->refcnt)) {
const struct net_device_ops *ops;
@@ -820,8 +824,7 @@ static void __netpoll_cleanup(struct netpoll *np)
RCU_INIT_POINTER(np->dev->npinfo, NULL);
call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
- } else
- RCU_INIT_POINTER(np->dev->npinfo, NULL);
+ }
skb_pool_flush(np);
}
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x a28352cf2d2f8380e7aca8cb61682396dca7a991
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112055-suspense-expiring-db69@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From a28352cf2d2f8380e7aca8cb61682396dca7a991 Mon Sep 17 00:00:00 2001
From: Shawn Lin <shawn.lin(a)rock-chips.com>
Date: Mon, 20 Oct 2025 09:49:41 +0800
Subject: [PATCH] mmc: sdhci-of-dwcmshc: Change DLL_STRBIN_TAPNUM_DEFAULT to
0x4
strbin signal delay under 0x8 configuration is not stable after massive
test. The recommandation of it should be 0x4.
Signed-off-by: Shawn Lin <shawn.lin(a)rock-chips.com>
Tested-by: Alexey Charkov <alchark(a)gmail.com>
Tested-by: Hugh Cole-Baker <sigmaris(a)gmail.com>
Fixes: 08f3dff799d4 ("mmc: sdhci-of-dwcmshc: add rockchip platform support")
Cc: stable(a)vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson(a)linaro.org>
diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
index eebd45389956..5b61401a7f3d 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -94,7 +94,7 @@
#define DLL_TXCLK_TAPNUM_DEFAULT 0x10
#define DLL_TXCLK_TAPNUM_90_DEGREES 0xA
#define DLL_TXCLK_TAPNUM_FROM_SW BIT(24)
-#define DLL_STRBIN_TAPNUM_DEFAULT 0x8
+#define DLL_STRBIN_TAPNUM_DEFAULT 0x4
#define DLL_STRBIN_TAPNUM_FROM_SW BIT(24)
#define DLL_STRBIN_DELAY_NUM_SEL BIT(26)
#define DLL_STRBIN_DELAY_NUM_OFFSET 16
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 49c8d2c1f94cc2f4d1a108530d7ba52614b874c2
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025112007-gyration-fifty-ac52@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 49c8d2c1f94cc2f4d1a108530d7ba52614b874c2 Mon Sep 17 00:00:00 2001
From: Breno Leitao <leitao(a)debian.org>
Date: Fri, 7 Nov 2025 06:03:37 -0800
Subject: [PATCH] net: netpoll: fix incorrect refcount handling causing
incorrect cleanup
commit efa95b01da18 ("netpoll: fix use after free") incorrectly
ignored the refcount and prematurely set dev->npinfo to NULL during
netpoll cleanup, leading to improper behavior and memory leaks.
Scenario causing lack of proper cleanup:
1) A netpoll is associated with a NIC (e.g., eth0) and netdev->npinfo is
allocated, and refcnt = 1
- Keep in mind that npinfo is shared among all netpoll instances. In
this case, there is just one.
2) Another netpoll is also associated with the same NIC and
npinfo->refcnt += 1.
- Now dev->npinfo->refcnt = 2;
- There is just one npinfo associated to the netdev.
3) When the first netpolls goes to clean up:
- The first cleanup succeeds and clears np->dev->npinfo, ignoring
refcnt.
- It basically calls `RCU_INIT_POINTER(np->dev->npinfo, NULL);`
- Set dev->npinfo = NULL, without proper cleanup
- No ->ndo_netpoll_cleanup() is either called
4) Now the second target tries to clean up
- The second cleanup fails because np->dev->npinfo is already NULL.
* In this case, ops->ndo_netpoll_cleanup() was never called, and
the skb pool is not cleaned as well (for the second netpoll
instance)
- This leaks npinfo and skbpool skbs, which is clearly reported by
kmemleak.
Revert commit efa95b01da18 ("netpoll: fix use after free") and adds
clarifying comments emphasizing that npinfo cleanup should only happen
once the refcount reaches zero, ensuring stable and correct netpoll
behavior.
Cc: <stable(a)vger.kernel.org> # 3.17.x
Cc: Jay Vosburgh <jv(a)jvosburgh.net>
Fixes: efa95b01da18 ("netpoll: fix use after free")
Signed-off-by: Breno Leitao <leitao(a)debian.org>
Reviewed-by: Simon Horman <horms(a)kernel.org>
Link: https://patch.msgid.link/20251107-netconsole_torture-v10-1-749227b55f63@deb…
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index c85f740065fc..331764845e8f 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -811,6 +811,10 @@ static void __netpoll_cleanup(struct netpoll *np)
if (!npinfo)
return;
+ /* At this point, there is a single npinfo instance per netdevice, and
+ * its refcnt tracks how many netpoll structures are linked to it. We
+ * only perform npinfo cleanup when the refcnt decrements to zero.
+ */
if (refcount_dec_and_test(&npinfo->refcnt)) {
const struct net_device_ops *ops;
@@ -820,8 +824,7 @@ static void __netpoll_cleanup(struct netpoll *np)
RCU_INIT_POINTER(np->dev->npinfo, NULL);
call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
- } else
- RCU_INIT_POINTER(np->dev->npinfo, NULL);
+ }
skb_pool_flush(np);
}