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1,462,193 commits

Author SHA1 Message Date
Harry Yoo
27125df9a5 mm/slab: drop the OBJEXTS_NOSPIN_ALLOC flag from enum objext_flags
OBJEXTS_NOSPIN_ALLOC was used to remember whether a slabobj_ext vector
was allocated via kmalloc_nolock(), so that free_slab_obj_exts() could
call kfree_nolock() instead of kfree().

Now that kfree() supports freeing kmalloc_nolock() objects, this flag is
no longer needed. Instead, pass the allow_spin parameter down to
free_slab_obj_exts() to determine whether kfree_nolock() or kfree()
should be called in the free path, and free one bit in
enum objext_flags.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Hao Li <hao.li@linux.dev>
Link: https://patch.msgid.link/20260210044642.139482-3-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-02-10 11:39:30 +01:00
Mateusz Guzik
87caaeef79
pidfs: implement ino allocation without the pidmap lock
This paves the way for scalable PID allocation later.

The 32 bit variant merely takes a spinlock for simplicity, the 64 bit
variant uses a scalable scheme.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260120184539.1480930-1-mjguzik@gmail.com
Co-developed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-10 11:39:30 +01:00
Oleg Nesterov
1cf2e88e06
Revert "pid: make __task_pid_nr_ns(ns => NULL) safe for zombie callers"
This reverts commit abdfd4948e.

The changelog in this commit explains why it is not easy to avoid ns == NULL
when the caller is exiting, but pid_vnr() is equally unsafe in this case.

However, commit 006568ab4c ("pid: Add a judgment for ns null in pid_nr_ns")
already added the ns != NULL check in pid_nr_ns(), so we can remove the same
check from __task_pid_nr_ns().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: https://patch.msgid.link/20251015123613.GA9456@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-10 11:39:30 +01:00
Harry Yoo
c4d6d78298 mm/slab: allow freeing kmalloc_nolock()'d objects using kfree[_rcu]()
Slab objects that are allocated with kmalloc_nolock() must be freed
using kfree_nolock() because only a subset of alloc hooks are called,
since kmalloc_nolock() can't spin on a lock during allocation.

This imposes a limitation: such objects cannot be freed with kfree_rcu(),
forcing users to work around this limitation by calling call_rcu()
with a callback that frees the object using kfree_nolock().

Remove this limitation by teaching kmemleak to gracefully ignore cases
when kmemleak_free() or kmemleak_ignore() is called without a prior
kmemleak_alloc().

Unlike kmemleak, kfence already handles this case, because,
due to its design, only a subset of allocations are served from kfence.

With this change, kfree() and kfree_rcu() can be used to free objects
that are allocated using kmalloc_nolock().

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Link: https://patch.msgid.link/20260210044642.139482-2-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-02-10 11:39:30 +01:00
Mateusz Guzik
03aef0602f
pid: reorder fields in pid_namespace to reduce false sharing
alloc_pid() loads pid_cachep, level and pid_max prior to taking the
lock.

It dirties idr and pid_allocated with the lock.

Some of these fields share the cacheline as is, split them up.

No change in the size of the struct.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://patch.msgid.link/20260120204820.1497002-1-mjguzik@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-10 11:39:30 +01:00
Christian Brauner
8021824904
pidfs: convert rb-tree to rhashtable
Mateusz reported performance penalties [1] during task creation because
pidfs uses pidmap_lock to add elements into the rbtree. Switch to an
rhashtable to have separate fine-grained locking and to decouple from
pidmap_lock moving all heavy manipulations outside of it.

Convert the pidfs inode-to-pid mapping from an rb-tree with seqcount
protection to an rhashtable. This removes the global pidmap_lock
contention from pidfs_ino_get_pid() lookups and allows the hashtable
insert to happen outside the pidmap_lock.

pidfs_add_pid() is split. pidfs_prepare_pid() allocates inode number and
initializes pid fields and is called inside pidmap_lock. pidfs_add_pid()
inserts pid into rhashtable and is called outside pidmap_lock. Insertion
into the rhashtable can fail and memory allocation may happen so we need
to drop the spinlock.

To guard against accidently opening an already reaped task
pidfs_ino_get_pid() uses additional checks beyond pid_vnr(). If
pid->attr is PIDFS_PID_DEAD or NULL the pid either never had a pidfd or
it already went through pidfs_exit() aka the process as already reaped.
If pid->attr is valid check PIDFS_ATTR_BIT_EXIT to figure out whether
the task has exited.

This slightly changes visibility semantics: pidfd creation is denied
after pidfs_exit() runs, which is just before the pid number is removed
from the via free_pid(). That should not be an issue though.

Link: https://lore.kernel.org/20251206131955.780557-1-mjguzik@gmail.com [1]
Link: https://patch.msgid.link/20260120-work-pidfs-rhashtable-v2-1-d593c4d0f576@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-10 11:39:30 +01:00
Tim Bird
a344860211
ipc: Add SPDX license id to mqueue.c
Add GPL-2.0 license id to file, replacing reference to
GPL in the header comment.

Signed-off-by: Tim Bird <tim.bird@sony.com>
Link: https://patch.msgid.link/20260117202759.692347-1-tim.bird@sony.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-02-10 11:39:30 +01:00
Claudio Imbrenda
f8f296ea1c KVM: s390: vsie: Fix race in acquire_gmap_shadow()
The shadow gmap returned by gmap_create_shadow() could get dropped
before taking the gmap->children_lock. This meant that the shadow gmap
was sometimes being used while its reference count was 0.

Fix this by taking the additional reference inside gmap_create_shadow()
while still holding gmap->children_lock, instead of afterwards.

Fixes: e38c884df9 ("KVM: s390: Switch to new gmap")
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-02-10 11:33:34 +01:00
Claudio Imbrenda
b6ab71a27c KVM: s390: vsie: Fix race in walk_guest_tables()
It is possible that walk_guest_tables() is called on a shadow gmap that
has been removed already, in which case its parent will be NULL.

In such case, return -EAGAIN and let the callers deal with it.

Fixes: e38c884df9 ("KVM: s390: Switch to new gmap")
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-02-10 11:33:30 +01:00
Claudio Imbrenda
898885477e KVM: s390: Use guest address to mark guest page dirty
Stop using the userspace address to mark the guest page dirty.
mark_page_dirty() expects a guest frame number, but was being passed a
host virtual frame number. When slot == NULL, mark_page_dirty_in_slot()
does nothing and does not complain.

This means that in some circumstances the dirtiness of the guest page
might have been lost.

Fix by adding two fields in struct kvm_s390_adapter_int to keep the
guest addressses, and use those for mark_page_dirty().

Fixes: f65470661f ("KVM: s390/interrupt: do not pin adapter interrupt pages")
Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
2026-02-10 11:33:25 +01:00
Jiayuan Chen
ae88a5d2f2 net: atm: fix crash due to unvalidated vcc pointer in sigd_send()
Reproducer available at [1].

The ATM send path (sendmsg -> vcc_sendmsg -> sigd_send) reads the vcc
pointer from msg->vcc and uses it directly without any validation. This
pointer comes from userspace via sendmsg() and can be arbitrarily forged:

    int fd = socket(AF_ATMSVC, SOCK_DGRAM, 0);
    ioctl(fd, ATMSIGD_CTRL);  // become ATM signaling daemon
    struct msghdr msg = { .msg_iov = &iov, ... };
    *(unsigned long *)(buf + 4) = 0xdeadbeef;  // fake vcc pointer
    sendmsg(fd, &msg, 0);  // kernel dereferences 0xdeadbeef

In normal operation, the kernel sends the vcc pointer to the signaling
daemon via sigd_enq() when processing operations like connect(), bind(),
or listen(). The daemon is expected to return the same pointer when
responding. However, a malicious daemon can send arbitrary pointer values.

Fix this by introducing find_get_vcc() which validates the pointer by
searching through vcc_hash (similar to how sigd_close() iterates over
all VCCs), and acquires a reference via sock_hold() if found.

Since struct atm_vcc embeds struct sock as its first member, they share
the same lifetime. Therefore using sock_hold/sock_put is sufficient to
keep the vcc alive while it is being used.

Note that there may be a race with sigd_close() which could mark the vcc
with various flags (e.g., ATM_VF_RELEASED) after find_get_vcc() returns.
However, sock_hold() guarantees the memory remains valid, so this race
only affects the logical state, not memory safety.

[1]: https://gist.github.com/mrpre/1ba5949c45529c511152e2f4c755b0f3
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: syzbot+1f22cb1769f249df9fa0@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/69039850.a70a0220.5b2ed.005d.GAE@google.com/T/
Signed-off-by: Jiayuan Chen <jiayuan.chen@shopee.com>
Link: https://patch.msgid.link/20260205095501.131890-1-jiayuan.chen@linux.dev
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 11:24:47 +01:00
Miguel Ojeda
c431b00ca6 objtool/rust: add one more noreturn Rust function
`objtool` with Rust 1.84.0 reports:

    rust/kernel.o: error: objtool: _RNvXNtNtCsaRPFapPOzLs_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix14from_str_radix()
    falls through to next function _RNvXNtNtCsaRPFapPOzLs_6kernel3str9parse_intaNtNtB2_7private12FromStrRadix16from_u64_negated()

This is very similar to commit c18f35e490 ("objtool/rust: add one more
`noreturn` Rust function"), which added `from_ascii_radix_panic` for Rust
1.86.0, except that Rust 1.84.0 ends up needing `from_str_radix_panic`.

Thus add it to the list to fix the warning.

Cc: FUJITA Tomonori <fujita.tomonori@gmail.com>
Fixes: 51d9ee90ea ("rust: str: add radix prefixed integer parsing functions")
Reported-by: Alice Ryhl <aliceryhl@google.com>
Link: https://rust-for-linux.zulipchat.com/#narrow/channel/291565/topic/x/with/572427627
Tested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260206204336.38462-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-02-10 11:01:16 +01:00
Matt Coster
4af267ce34
drm/imagination: Mark FWCCB_CMD_UPDATE_STATS as known
Suppress the "unknown type" warning when processing a FWCCB command of
type CMD_UPDATE_STATS which is known but (currently) unused.

Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Link: https://patch.msgid.link/20260206-improve-bad-fwccb-cmd-v1-2-831a852ca127@imgtec.com
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
2026-02-10 10:01:11 +00:00
Matt Coster
c7384288d9
drm/imagination: Improve handling of unknown FWCCB commands
A couple small changes:
 - Validate the magic value at the head of FWCCB commands, and
 - Mask off the magic value before logging unknown command types to make
   them easier to interpret on sight.

Reviewed-by: Frank Binns <frank.binns@imgtec.com>
Link: https://patch.msgid.link/20260206-improve-bad-fwccb-cmd-v1-1-831a852ca127@imgtec.com
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
2026-02-10 10:01:10 +00:00
Paolo Abeni
310d80b0f8 Merge branch 'net-fec-improve-xdp-copy-mode-and-add-af_xdp-zero-copy-support'
Wei Fang says:

====================
net: fec: improve XDP copy mode and add AF_XDP zero-copy support

This patch set optimizes the XDP copy mode logic as follows.

1. Separate the processing of RX XDP frames from fec_enet_rx_queue(),
and adds a separate function fec_enet_rx_queue_xdp() for handling XDP
frames.

2. For TX XDP packets, using the batch sending method to avoid frequent
MMIO writes.

3. Use the switch statement to check the tx_buf type instead of the
if...else... statement, making the cleanup logic of TX BD ring cleared
and more efficient.

We compared the performance of XDP copy mode before and after applying
this patch set, and the results show that the performance has improved.

Before applying this patch set.
root@imx93evk:~# ./xdp-bench tx eth0
Summary                   396,868 rx/s                  0 err,drop/s
Summary                   396,024 rx/s                  0 err,drop/s

root@imx93evk:~# ./xdp-bench drop eth0
Summary                   684,781 rx/s                  0 err/s
Summary                   675,746 rx/s                  0 err/s

root@imx93evk:~# ./xdp-bench pass eth0
Summary                   208,552 rx/s                  0 err,drop/s
Summary                   208,654 rx/s                  0 err,drop/s

root@imx93evk:~# ./xdp-bench redirect eth0 eth0
eth0->eth0                311,210 rx/s                  0 err,drop/s      311,208 xmit/s
eth0->eth0                310,808 rx/s                  0 err,drop/s      310,809 xmit/s

After applying this patch set.
root@imx93evk:~# ./xdp-bench tx eth0
Summary                   425,778 rx/s                  0 err,drop/s
Summary                   426,042 rx/s                  0 err,drop/s

root@imx93evk:~# ./xdp-bench drop eth0
Summary                   698,351 rx/s                  0 err/s
Summary                   701,882 rx/s                  0 err/s

root@imx93evk:~# ./xdp-bench pass eth0
Summary                   210,348 rx/s                  0 err,drop/s
Summary                   210,016 rx/s                  0 err,drop/s

root@imx93evk:~# ./xdp-bench redirect eth0 eth0
eth0->eth0                354,407 rx/s                  0 err,drop/s      354,401 xmit/s
eth0->eth0                350,381 rx/s                  0 err,drop/s      350,389 xmit/s

This patch set also addes the AF_XDP zero-copy support, and we tested
the performance on i.MX93 platform with xdpsock tool. The following is
the performance comparison of copy mode and zero-copy mode. It can be
seen that the performance of zero-copy mode is better than that of copy
mode.

1. MAC swap L2 forwarding
1.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -z
 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 414715         415455
tx                 414715         415455

1.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -c
 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 356396         356609
tx                 356396         356609

2. TX only
2.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -z
 sock0@eth0:0 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 1119573        1126720

2.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -c
sock0@eth0:0 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 406864         407616
====================

Link: https://patch.msgid.link/20260205085742.2685134-1-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:23 +01:00
Wei Fang
25eb3058eb net: fec: add AF_XDP zero-copy support
This patch adds AF_XDP zero-copy support for both TX and RX on the FEC
driver. It introduces new functions for XSK buffer allocation, RX/TX
queue processing in zero-copy mode, and XSK pool setup/teardown.

For RX, fec_alloc_rxq_buffers_zc() is added to allocate RX buffers from
XSK pool. And fec_enet_rx_queue_xsk() is used to process the frames from
the RX queue which is bound to the AF_XDP socket. Similar to the copy
mode, the zero-copy mode also supports XDP_TX, XDP_PASS, XDP_DROP and
XDP_REDIRECT actions. In addition, fec_enet_xsk_tx_xmit() is similar to
fec_enet_xdp_tx_xmit() and is used to handle XDP_TX action in zero-copy
mode.

For TX, there are two cases, one is the frames from the AF_XDP socket,
so fec_enet_xsk_xmit() is added to directly transmit the frames from
the socket and the buffer type is marked as FEC_TXBUF_T_XSK_XMIT. The
other one is the frames from the RX queue (XDP_TX action), the buffer
type is marked as FEC_TXBUF_T_XSK_TX. Therefore, fec_enet_tx_queue()
could correctly clean the TX queue base on the buffer type.

Also, some tests have been done on the i.MX93-EVK board with the xdpsock
tool, the following are the results.

Env: i.MX93 connects to a packet generator, the link speed is 1Gbps, and
flow-control is off. The RX packet size is 64 bytes including FCS. Only
one RX queue (CPU) is used to receive frames.

1. MAC swap L2 forwarding
1.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -z
 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 414715         415455
tx                 414715         415455

1.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -l -c
 sock0@eth0:0 l2fwd xdp-drv
                   pps            pkts           1.00
rx                 356396         356609
tx                 356396         356609

2. TX only
2.1 Zero-copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -z
 sock0@eth0:0 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 1119573        1126720

2.2 Copy mode
root@imx93evk:~# ./xdpsock -i eth0 -t -s 64 -c
sock0@eth0:0 txonly xdp-drv
                   pps            pkts           1.00
rx                 0              0
tx                 406864         407616

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-16-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
fee723a48c net: fec: improve fec_enet_tx_queue()
To support AF_XDP zero-copy mode in the subsequent patch, the following
adjustments have been made to fec_tx_queue().

1. Change the parameters of fec_tx_queue().
2. Some variables are initialized at the time of declaration, and the
order of local variables is updated to follow the reverse xmas tree
style.
3. Remove the variable xdpf and add the variable tx_buf.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-15-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
a2ae70c0ef net: fec: add fec_alloc_rxq_buffers_pp() to allocate buffers from page pool
Currently, the buffers of RX queue are allocated from the page pool. In
the subsequent patches to support XDP zero copy, the RX buffers will be
allocated from the UMEM. Therefore, extract fec_alloc_rxq_buffers_pp()
from fec_enet_alloc_rxq_buffers() and we will add another helper to
allocate RX buffers from UMEM for the XDP zero copy mode. In addition,
fec_alloc_rxq_buffers_pp() only initializes bdp->bufaddr and does not
initialize other fields of bdp, because these will be initialized in
fec_enet_bd_init().

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-14-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
edd393153e net: fec: move xdp_rxq_info* APIs out of fec_enet_create_page_pool()
Extract fec_xdp_rxq_info_reg() from fec_enet_create_page_pool() and move
it out of fec_enet_create_page_pool(), so that it can be reused in the
subsequent patches to support XDP zero copy mode.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-13-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
6729b24c1c net: fec: remove the size parameter from fec_enet_create_page_pool()
Remove the size parameter from fec_enet_create_page_pool(), since
rxq->bd.ring_size already contains this information.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-12-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
8492e4f195 net: fec: use switch statement to check the type of tx_buf
The tx_buf has three types: FEC_TXBUF_T_SKB, FEC_TXBUF_T_XDP_NDO and
FEC_TXBUF_T_XDP_TX. Currently, the driver uses 'if...else...' statements
to check the type and perform the corresponding processing. This is very
detrimental to future expansion. To support AF_XDP zero-copy mode, two
new types will be added in the future, continuing to use 'if...else...'
would be a very bad coding style. So the 'if...else...' statements in
the current driver are replaced with switch statements.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-11-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
2dcc934755 net: fec: remove unnecessary NULL pointer check when clearing TX BD ring
The tx_buf pointer will not NULL when its type is FEC_TXBUF_T_XDP_NDO or
FEC_TXBUF_T_XDP_TX. If the type is FEC_TXBUF_T_SKB, dev_kfree_skb_any()
will do NULL pointer check. So it is unnecessary to do NULL pointer check
in fec_enet_bd_init() and fec_enet_tx_queue().

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-10-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
2ff7a7d392 net: fec: transmit XDP frames in bulk
Currently, the driver writes the ENET_TDAR register for every XDP frame
to trigger transmit start. Frequent MMIO writes consume more CPU cycles
and may reduce XDP TX performance, so transmit XDP frames in bulk.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-9-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
8a3344bb73 net: fec: add tx_qid parameter to fec_enet_xdp_tx_xmit()
Remove fec_enet_xdp_get_tx_queue() from fec_enet_xdp_tx_xmit() and add
the tx_qid parameter to it. Then, calculate the TX queue ID for XDP_TX
frames in fec_enet_rx_queue_xdp(). This way, the TX queue ID only needs
to be calculated once for XDP_TX frames during each NAPI polling. And
since the number of RX queues and TX queues in FEC is generally equal,
the RX queue ID can be directly used as the TX queue ID. In exceptional
cases, fec_enet_xdp_get_tx_queue() is used to calculate the TX queue ID.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-8-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
5ff3d3ddcd net: fec: add fec_enet_rx_queue_xdp() for XDP path
Currently, the processing of XDP path packets and protocol stack packets
are both mixed in fec_enet_rx_queue(), which makes the logic somewhat
confusing and debugging more difficult. Furthermore, some logic is not
needed by each other. Such as the kernel path does not need to call
xdp_init_buff(), XDP path does not support swap_buffer(), because
fec_enet_bpf() returns "-EOPNOTSUPP" for those platforms which need
swap_buffer()), and so on. This prevents XDP from achieving its maximum
performance. Therefore, XDP path packets processing has been separated
from fec_enet_rx_queue() by adding the fec_enet_rx_queue_xdp() function
to optimize XDP path logic and improve XDP performance.

The XDP performance on the iMX93 platform was compared before and after
applying this patch. Detailed results are as follows and we can see the
performance has been improved.

Env: i.MX93, packet size 64 bytes including FCS, only single core and RX
BD ring are used to receive packets, flow-control is off.

Before the patch is applied:
xdp-bench tx eth0
Summary                   396,868 rx/s                  0 err,drop/s
Summary                   396,024 rx/s                  0 err,drop/s

xdp-bench drop eth0
Summary                   684,781 rx/s                  0 err/s
Summary                   675,746 rx/s                  0 err/s

xdp-bench pass eth0
Summary                   208,552 rx/s                  0 err,drop/s
Summary                   208,654 rx/s                  0 err,drop/s

xdp-bench redirect eth0 eth0
eth0->eth0                311,210 rx/s                  0 err,drop/s      311,208 xmit/s
eth0->eth0                310,808 rx/s                  0 err,drop/s      310,809 xmit/s

After the patch is applied:
xdp-bench tx eth0
Summary                   409,975 rx/s                  0 err,drop/s
Summary                   411,073 rx/s                  0 err,drop/s

xdp-bench drop eth0
Summary                   700,681 rx/s                  0 err/s
Summary                   698,102 rx/s                  0 err/s

xdp-bench pass eth0
Summary                   211,356 rx/s                  0 err,drop/s
Summary                   210,629 rx/s                  0 err,drop/s

xdp-bench redirect eth0 eth0
eth0->eth0                320,351 rx/s                  0 err,drop/s      320,348 xmit/s
eth0->eth0                318,988 rx/s                  0 err,drop/s      318,988 xmit/s

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-7-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:20 +01:00
Wei Fang
bc609f97b1 net: fec: improve fec_enet_rx_queue()
This patch has made the following adjustments to fec_enet_rx_queue().

1. The function parameters are modified to maintain the same style as
subsequently added XDP-related interfaces.

2. Some variables are initialized at the time of declaration, and the
order of local variables is updated to follow the reverse xmas tree
style.

3. Replace variable cbd_bufaddr with dma.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-6-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:19 +01:00
Wei Fang
54a6e86ba4 net: fec: add fec_build_skb() to build a skb
Extract the helper fec_build_skb() from fec_enet_rx_queue(), so that the
code for building a skb is centralized in fec_build_skb(), which makes
the code of fec_enet_rx_queue() more concise and readable.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-5-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:19 +01:00
Wei Fang
385d19b567 net: fec: add rx_shift to indicate the extra bytes padded in front of RX frame
The FEC of some platforms supports RX FIFO shift-16, it means the actual
frame data starts at bit 16 of the first word read from RX FIFO aligning
the Ethernet payload on a 32-bit boundary. The MAC writes two additional
bytes in front of each frame received into the RX FIFO. Currently, the
fec_enet_rx_queue() updates the data_start, sub_len and the rx_bytes
statistics by checking whether FEC_QUIRK_HAS_RACC is set. This makes the
code less concise, so rx_shift is added to represent the number of extra
bytes padded in front of the RX frame. Furthermore, when adding separate
RX handling functions for XDP copy mode and zero copy mode in the future,
it will no longer be necessary to check FEC_QUIRK_HAS_RACC to update the
corresponding variables.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-4-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:19 +01:00
Wei Fang
ff306e9a19 net: fec: add fec_rx_error_check() to check RX errors
Extract fec_rx_error_check() from fec_enet_rx_queue(), this helper is
used to check RX errors. And it will be used in XDP and XDP zero copy
paths in subsequent patches.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-3-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:19 +01:00
Wei Fang
c8d4ad9176 net: fec: add fec_txq_trigger_xmit() helper
Currently, the workaround for FEC_QUIRK_ERR007885 has three call sites,
so add the helper fec_txq_trigger_xmit() to make the code more concise
and reusable.

Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260205085742.2685134-2-wei.fang@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:58:19 +01:00
Harry Yoo
a1e244a9f1 mm/slab: use prandom if !allow_spin
When CONFIG_SLAB_FREELIST_RANDOM is enabled and get_random_u32()
is called in an NMI context, lockdep complains because it acquires
a local_lock:

  ================================
  WARNING: inconsistent lock state
  6.19.0-rc5-slab-for-next+ #325 Tainted: G                 N
  --------------------------------
  inconsistent {INITIAL USE} -> {IN-NMI} usage.
  kunit_try_catch/8312 [HC2[2]:SC0[0]:HE0:SE1] takes:
  ffff88a02ec49cc0 (batched_entropy_u32.lock){-.-.}-{3:3}, at: get_random_u32+0x7f/0x2e0
  {INITIAL USE} state was registered at:
    lock_acquire+0xd9/0x2f0
    get_random_u32+0x93/0x2e0
    __get_random_u32_below+0x17/0x70
    cache_random_seq_create+0x121/0x1c0
    init_cache_random_seq+0x5d/0x110
    do_kmem_cache_create+0x1e0/0xa30
    __kmem_cache_create_args+0x4ec/0x830
    create_kmalloc_caches+0xe6/0x130
    kmem_cache_init+0x1b1/0x660
    mm_core_init+0x1d8/0x4b0
    start_kernel+0x620/0xcd0
    x86_64_start_reservations+0x18/0x30
    x86_64_start_kernel+0xf3/0x140
    common_startup_64+0x13e/0x148
  irq event stamp: 76
  hardirqs last  enabled at (75): [<ffffffff8298b77a>] exc_nmi+0x11a/0x240
  hardirqs last disabled at (76): [<ffffffff8298b991>] sysvec_irq_work+0x11/0x110
  softirqs last  enabled at (0): [<ffffffff813b2dda>] copy_process+0xc7a/0x2350
  softirqs last disabled at (0): [<0000000000000000>] 0x0

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(batched_entropy_u32.lock);
    <Interrupt>
      lock(batched_entropy_u32.lock);

   *** DEADLOCK ***

Fix this by using pseudo-random number generator if !allow_spin.
This means kmalloc_nolock() users won't get truly random numbers,
but there is not much we can do about it.

Note that an NMI handler might interrupt prandom_u32_state() and
change the random state, but that's safe.

Link: https://lore.kernel.org/all/0c33bdee-6de8-4d9f-92ca-4f72c1b6fb9f@suse.cz
Fixes: af92793e52 ("slab: Introduce kmalloc_nolock() and kfree_nolock().")
Cc: stable@vger.kernel.org
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Link: https://patch.msgid.link/20260210081900.329447-3-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-02-10 10:55:32 +01:00
Harry Yoo
144080a582 mm/slab: do not access current->mems_allowed_seq if !allow_spin
Lockdep complains when get_from_any_partial() is called in an NMI
context, because current->mems_allowed_seq is seqcount_spinlock_t and
not NMI-safe:

  ================================
  WARNING: inconsistent lock state
  6.19.0-rc5-kfree-rcu+ #315 Tainted: G                 N
  --------------------------------
  inconsistent {INITIAL USE} -> {IN-NMI} usage.
  kunit_try_catch/9989 [HC1[1]:SC0[0]:HE0:SE1] takes:
  ffff889085799820 (&____s->seqcount#3){.-.-}-{0:0}, at: ___slab_alloc+0x58f/0xc00
  {INITIAL USE} state was registered at:
    lock_acquire+0x185/0x320
    kernel_init_freeable+0x391/0x1150
    kernel_init+0x1f/0x220
    ret_from_fork+0x736/0x8f0
    ret_from_fork_asm+0x1a/0x30
  irq event stamp: 56
  hardirqs last  enabled at (55): [<ffffffff850a68d7>] _raw_spin_unlock_irq+0x27/0x70
  hardirqs last disabled at (56): [<ffffffff850858ca>] __schedule+0x2a8a/0x6630
  softirqs last  enabled at (0): [<ffffffff81536711>] copy_process+0x1dc1/0x6a10
  softirqs last disabled at (0): [<0000000000000000>] 0x0

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&____s->seqcount#3);
    <Interrupt>
      lock(&____s->seqcount#3);

   *** DEADLOCK ***

According to Documentation/locking/seqlock.rst, seqcount_t is not
NMI-safe and seqcount_latch_t should be used when read path can interrupt
the write-side critical section. In this case, do not access
current->mems_allowed_seq and avoid retry.

Fixes: af92793e52 ("slab: Introduce kmalloc_nolock() and kfree_nolock().")
Cc: stable@vger.kernel.org
Signed-off-by: Harry Yoo <harry.yoo@oracle.com>
Link: https://patch.msgid.link/20260210081900.329447-2-harry.yoo@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
2026-02-10 10:55:31 +01:00
Ethan Nelson-Moore
d82cb7b7ec net: arcnet: com20020-pci: use module_pci_driver
The only thing this driver's init/exit functions do is call
pci_register/unregister_driver, and in the case of the init function,
print an unnecessary message. Replace them with module_pci_driver to
simplify the code.

Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260205070632.37516-1-enelsonmoore@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 10:16:33 +01:00
Imre Deak
7229474d41 drm/i915/dp: Verify valid pipe BPP range
Ensure that the pipe BPP range is valid after calculating the minimum
and maximum pipe BPP values separately.

Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260209133817.395823-2-imre.deak@intel.com
2026-02-10 11:12:02 +02:00
Imre Deak
08b7ef16b6 drm/i915/dp: Fix pipe BPP clamping due to HDR
The pipe BPP value shouldn't be set outside of the source's / sink's
valid pipe BPP range, ensure this when increasing the minimum pipe BPP
value to 30 due to HDR.

While at it debug print if the HDR mode was requested for a connector by
setting the corresponding HDR connector property. This indicates
if the requested HDR mode could not be enabled, since the selected
pipe BPP is below 30, due to a sink capability or link BW limit.

v2:
- Also handle the case where the sink could support the target 30 BPP
  only in DSC mode due to a BW limit, but the sink doesn't support DSC
  or 30 BPP as a DSC input BPP. (Chaitanya)
- Debug print the connector's HDR mode in the link config dump, to
  indicate if a BPP >= 30 required by HDR couldn't be reached. (Ankit)
- Add Closes: trailer. (Ankit)
- Don't print the 30 BPP-outside of valid BPP range debug message if
  the min BPP is already > 30 (and so a target BPP >= 30 required
  for HDR is ensured).

Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/7052
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15503
Fixes: ba49a4643c ("drm/i915/dp: Set min_bpp limit to 30 in HDR mode")
Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Cc: <stable@vger.kernel.org> # v6.18+
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com> # v1
Reviewed-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patch.msgid.link/20260209133817.395823-1-imre.deak@intel.com
2026-02-10 11:10:57 +02:00
Maxime Ripard
5491f66891
drm/vc4: Switch private_obj initialization to atomic_create_state
The vc4 driver relies on a drm_private_obj, that is initialized by
allocating and initializing a state, and then passing it to
drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-14-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:07:57 +01:00
Maxime Ripard
9bf5b4dfe1
drm/msm: dpu1: Switch private_obj initialization to atomic_create_state
The MSM dpu1 driver relies on a drm_private_obj, that is initialized by
allocating and initializing a state, and then passing it to
drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-11-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:07:17 +01:00
Maxime Ripard
4ada3ac5ff
drm/msm: mdp5: Switch private_obj initialization to atomic_create_state
The MSM mdp5 driver relies on a drm_private_obj, that is initialized by
allocating and initializing a state, and then passing it to
drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-10-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:07:11 +01:00
Maxime Ripard
8e46b1ebf3
drm/ingenic: Switch private_obj initialization to atomic_create_state
The ingenic driver relies on two drm_private_objs, that are initialized
by allocating and initializing a state, and then passing it to
drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Acked-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-9-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:07:05 +01:00
Maxime Ripard
d2bbd8a427
drm/arm: komeda: Switch private_obj initialization to atomic_create_state
The ARM komeda driver relies on a number of drm_private_objs, that are
initialized by allocating and initializing a state, and then passing it
to drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-8-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:06:57 +01:00
Maxime Ripard
8e6da25bd6
drm/dp_tunnel: Switch private_obj initialization to atomic_create_state
The DP tunnel implementation relies on a drm_private_obj, that is
initialized by allocating and initializing a state, and then passing it
to drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-6-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:06:36 +01:00
Maxime Ripard
2dce31863b
drm/dp_mst: Switch private_obj initialization to atomic_create_state
The DP MST implementation relies on a drm_private_obj, that is
initialized by allocating and initializing a state, and then passing it
to drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-5-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:06:07 +01:00
Maxime Ripard
ca8453ce03
drm/bridge: Switch private_obj initialization to atomic_create_state
The bridge implementation relies on a drm_private_obj, that is
initialized by allocating and initializing a state, and then passing it
to drm_private_obj_init.

Since we're gradually moving away from that pattern to the more
established one relying on a atomic_create_state implementation, let's
migrate this instance to the new pattern.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-4-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:05:58 +01:00
Maxime Ripard
e7be39ed17
drm/atomic-helper: Add private_obj atomic_create_state helper
Now that we have an atomic_create_state callback for drm_private_objs,
we can provide a helper for it.

It's somewhat different from the other similar helpers though, because
we definitely expect drm_private_obj to be subclassed. It wouldn't make
sense for a driver to use it as-is.

So we can't provide a straight implementation of the atomic_create_state
callback, but rather we provide the parts that will deal with the
drm_private_obj initialization, and we will leave the allocation and
initialization of the subclass to drivers.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-3-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:05:39 +01:00
Maxime Ripard
47b5ac7daa
drm/atomic: Add new atomic_create_state callback to drm_private_obj
The drm_private_obj initialization was inconsistent with the rest of the
KMS objects. Indeed, it required to pass a preallocated state in
drm_private_obj_init(), while all the others objects would have a reset
callback that would be called later on to create the state.

However, reset really is meant to reset the hardware and software state.
That it creates an initial state is a side-effect that has been used in
all objects but drm_private_obj. This is made more complex since some
drm_private_obj, the DisplayPort ones in particular, need to be
persistent across and suspend/resume cycle, and such a cycle would call
drm_mode_config_reset().

Thus, we need to add a new callback to allocate a pristine state for a
given private object.

This discussion has also came up during the atomic state readout
discussion, so it might be introduced into the other objects later on.

Until all drivers are converted to that new allocation pattern, we will
only call it if the passed state is NULL. This will be removed
eventually.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-2-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:05:33 +01:00
Maxime Ripard
95ffa10056
drm/atomic: Make drm_atomic_private_obj_init fallible
Since we're going to move the drm_private_obj state allocation to a
callback, we need to be able to deal with its possible failure.

Make drm_private_obj_init return an error code on failure.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patch.msgid.link/20260128-drm-private-obj-reset-v4-1-90891fa3d3b0@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>
2026-02-10 10:05:23 +01:00
Colin Lord
f743435f98 tracing: Fix false sharing in hwlat get_sample()
The get_sample() function in the hwlat tracer assumes the caller holds
hwlat_data.lock, but this is not actually happening. The result is
unprotected data access to hwlat_data, and in per-cpu mode can result in
false sharing which may show up as false positive latency events.

The specific case of false sharing observed was primarily between
hwlat_data.sample_width and hwlat_data.count. These are separated by
just 8B and are therefore likely to share a cache line. When one thread
modifies count, the cache line is in a modified state so when other
threads read sample_width in the main latency detection loop, they fetch
the modified cache line. On some systems, the fetch itself may be slow
enough to count as a latency event, which could set up a self
reinforcing cycle of latency events as each event increments count which
then causes more latency events, continuing the cycle.

The other result of the unprotected data access is that hwlat_data.count
can end up with duplicate or missed values, which was observed on some
systems in testing.

Convert hwlat_data.count to atomic64_t so it can be safely modified
without locking, and prevent false sharing by pulling sample_width into
a local variable.

One system this was tested on was a dual socket server with 32 CPUs on
each numa node. With settings of 1us threshold, 1000us width, and
2000us window, this change reduced the number of latency events from
500 per second down to approximately 1 event per minute. Some machines
tested did not exhibit measurable latency from the false sharing.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20260210074810.6328-1-clord@mykolab.com
Signed-off-by: Colin Lord <clord@mykolab.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-10 03:36:39 -05:00
Miguel Ojeda
0a9be83e57 rust: kbuild: pass -Zunstable-options for Rust 1.95.0
Custom target specifications are unstable, but starting with Rust 1.95.0,
`rustc` requires to explicitly pass `-Zunstable-options` to use them [1]:

    error: error loading target specification: custom targets are unstable and require `-Zunstable-options`
      |
      = help: run `rustc --print target-list` for a list of built-in targets

David (Rust compiler team lead), writes:

   "We're destabilising custom targets to allow us to move forward with
    build-std without accidentally exposing functionality that we'd like
    to revisit prior to committing to. I'll start a thread on Zulip to
    discuss with the RfL team how we can come up with an alternative
    for them."

Thus pass it.

Cc: David Wood <david@davidtw.co>
Cc: Wesley Wiser <wwiser@gmail.com>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/151534 [1]
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260206204535.39431-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-02-10 09:13:31 +01:00
Vlastimil Babka
815c8e3551 Merge branch 'slab/for-7.0/sheaves' into slab/for-next
Merge series "slab: replace cpu (partial) slabs with sheaves".

The percpu sheaves caching layer was introduced as opt-in but the goal
was to eventually move all caches to them. This is the next step,
enabling sheaves for all caches (except the two bootstrap ones) and then
removing the per cpu (partial) slabs and lots of associated code.

Besides the lower locking overhead and much more likely fastpath when
freeing, this removes the rather complicated code related to the cpu
slab lockless fastpaths (using this_cpu_try_cmpxchg128/64) and all its
complications for PREEMPT_RT or kmalloc_nolock().

The lockless slab freelist+counters update operation using
try_cmpxchg128/64 remains and is crucial for freeing remote NUMA objects
and to allow flushing objects from sheaves to slabs mostly without the
node list_lock.

Link: https://lore.kernel.org/all/20260123-sheaves-for-all-v4-0-041323d506f7@suse.cz/
2026-02-10 09:10:00 +01:00
Paolo Abeni
30827969b0 Merge branch 'net-dsa-mxl-gsw1xx-setup-polarities-and-validate-chip'
Daniel Golle says:

====================
net: dsa: mxl-gsw1xx: setup polarities and validate chip

Now that common PHY properties make it easy to configure the SerDes RX
and TX polarities, use that for the SGMII/1000Base-X/2500Base-X port of
the MaxLinear GSW1xx switches.

Also, validate hardware in probe() function to make sure the switch is
actually present and MDIO communication works properly.
====================

Link: https://patch.msgid.link/cover.1769916962.git.daniel@makrotopia.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-10 09:09:32 +01:00