Merge tag 'v6.6.48' into for/openbmc/dev-6.6

This is the 6.6.48 stable release

rcu: Dump memory object info if callback function is invalid

[ Upstream commit 2cbc482d325ee58001472c4359b311958c4efdd1 ]

When a structure containing an RCU callback rhp is (incorrectly) freed
and

rcu: Dump memory object info if callback function is invalid

[ Upstream commit 2cbc482d325ee58001472c4359b311958c4efdd1 ]

When a structure containing an RCU callback rhp is (incorrectly) freed
and reallocated after rhp is passed to call_rcu(), it is not unusual for
rhp->func to be set to NULL. This defeats the debugging prints used by
__call_rcu_common() in kernels built with CONFIG_DEBUG_OBJECTS_RCU_HEAD=y,
which expect to identify the offending code using the identity of this
function.

And in kernels build without CONFIG_DEBUG_OBJECTS_RCU_HEAD=y, things
are even worse, as can be seen from this splat:

Unable to handle kernel NULL pointer dereference at virtual address 0
... ...
PC is at 0x0
LR is at rcu_do_batch+0x1c0/0x3b8
... ...
(rcu_do_batch) from (rcu_core+0x1d4/0x284)
(rcu_core) from (__do_softirq+0x24c/0x344)
(__do_softirq) from (__irq_exit_rcu+0x64/0x108)
(__irq_exit_rcu) from (irq_exit+0x8/0x10)
(irq_exit) from (__handle_domain_irq+0x74/0x9c)
(__handle_domain_irq) from (gic_handle_irq+0x8c/0x98)
(gic_handle_irq) from (__irq_svc+0x5c/0x94)
(__irq_svc) from (arch_cpu_idle+0x20/0x3c)
(arch_cpu_idle) from (default_idle_call+0x4c/0x78)
(default_idle_call) from (do_idle+0xf8/0x150)
(do_idle) from (cpu_startup_entry+0x18/0x20)
(cpu_startup_entry) from (0xc01530)

This commit therefore adds calls to mem_dump_obj(rhp) to output some
information, for example:

slab kmalloc-256 start ffff410c45019900 pointer offset 0 size 256

This provides the rough size of the memory block and the offset of the
rcu_head structure, which as least provides at least a few clues to help
locate the problem. If the problem is reproducible, additional slab
debugging can be enabled, for example, CONFIG_DEBUG_SLAB=y, which can
provide significantly more information.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

Merge tag 'v6.6.11' into dev-6.6

This is the 6.6.11 stable release

rcu: Introduce rcu_cpu_online()

[ Upstream commit 2be4686d866ad5896f2bb94d82fe892197aea9c7 ]

Export the RCU point of view as to when a CPU is considered offline
(ie: when does RCU consider that a C

rcu: Introduce rcu_cpu_online()

[ Upstream commit 2be4686d866ad5896f2bb94d82fe892197aea9c7 ]

Export the RCU point of view as to when a CPU is considered offline
(ie: when does RCU consider that a CPU is sufficiently down in the
hotplug process to not feature any possible read side).

This will be used by RCU-tasks whose vision of an offline CPU should
reasonably match the one of RCU core.

Fixes: cff9b2332ab7 ("kernel/sched: Modify initial boot task idle setup")
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

show more ...

Merge drm/drm-fixes into drm-misc-fixes

Forwarding to v6.6-rc1.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge branch 'next' into for-linus

Prepare input updates for 6.6 merge window.

Merge tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
"Core:

- Increase size limits for to-be-sent skb frag allocat

Merge tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
"Core:

- Increase size limits for to-be-sent skb frag allocations. This
allows tun, tap devices and packet sockets to better cope with
large writes operations

- Store netdevs in an xarray, to simplify iterating over netdevs

- Refactor nexthop selection for multipath routes

- Improve sched class lifetime handling

- Add backup nexthop ID support for bridge

- Implement drop reasons support in openvswitch

- Several data races annotations and fixes

- Constify the sk parameter of routing functions

- Prepend kernel version to netconsole message

Protocols:

- Implement support for TCP probing the peer being under memory
pressure

- Remove hard coded limitation on IPv6 specific info placement inside
the socket struct

- Get rid of sysctl_tcp_adv_win_scale and use an auto-estimated per
socket scaling factor

- Scaling-up the IPv6 expired route GC via a separated list of
expiring routes

- In-kernel support for the TLS alert protocol

- Better support for UDP reuseport with connected sockets

- Add NEXT-C-SID support for SRv6 End.X behavior, reducing the SR
header size

- Get rid of additional ancillary per MPTCP connection struct socket

- Implement support for BPF-based MPTCP packet schedulers

- Format MPTCP subtests selftests results in TAP

- Several new SMC 2.1 features including unique experimental options,
max connections per lgr negotiation, max links per lgr negotiation

BPF:

- Multi-buffer support in AF_XDP

- Add multi uprobe BPF links for attaching multiple uprobes and usdt
probes, which is significantly faster and saves extra fds

- Implement an fd-based tc BPF attach API (TCX) and BPF link support
on top of it

- Add SO_REUSEPORT support for TC bpf_sk_assign

- Support new instructions from cpu v4 to simplify the generated code
and feature completeness, for x86, arm64, riscv64

- Support defragmenting IPv(4|6) packets in BPF

- Teach verifier actual bounds of bpf_get_smp_processor_id() and fix
perf+libbpf issue related to custom section handling

- Introduce bpf map element count and enable it for all program types

- Add a BPF hook in sys_socket() to change the protocol ID from
IPPROTO_TCP to IPPROTO_MPTCP to cover migration for legacy

- Introduce bpf_me_mcache_free_rcu() and fix OOM under stress

- Add uprobe support for the bpf_get_func_ip helper

- Check skb ownership against full socket

- Support for up to 12 arguments in BPF trampoline

- Extend link_info for kprobe_multi and perf_event links

Netfilter:

- Speed-up process exit by aborting ruleset validation if a fatal
signal is pending

- Allow NLA_POLICY_MASK to be used with BE16/BE32 types

Driver API:

- Page pool optimizations, to improve data locality and cache usage

- Introduce ndo_hwtstamp_get() and ndo_hwtstamp_set() to avoid the
need for raw ioctl() handling in drivers

- Simplify genetlink dump operations (doit/dumpit) providing them the
common information already populated in struct genl_info

- Extend and use the yaml devlink specs to [re]generate the split ops

- Introduce devlink selective dumps, to allow SF filtering SF based
on handle and other attributes

- Add yaml netlink spec for netlink-raw families, allow route, link
and address related queries via the ynl tool

- Remove phylink legacy mode support

- Support offload LED blinking to phy

- Add devlink port function attributes for IPsec

New hardware / drivers:

- Ethernet:
- Broadcom ASP 2.0 (72165) ethernet controller
- MediaTek MT7988 SoC
- Texas Instruments AM654 SoC
- Texas Instruments IEP driver
- Atheros qca8081 phy
- Marvell 88Q2110 phy
- NXP TJA1120 phy

- WiFi:
- MediaTek mt7981 support

- Can:
- Kvaser SmartFusion2 PCI Express devices
- Allwinner T113 controllers
- Texas Instruments tcan4552/4553 chips

- Bluetooth:
- Intel Gale Peak
- Qualcomm WCN3988 and WCN7850
- NXP AW693 and IW624
- Mediatek MT2925

Drivers:

- Ethernet NICs:
- nVidia/Mellanox:
- mlx5:
- support UDP encapsulation in packet offload mode
- IPsec packet offload support in eswitch mode
- improve aRFS observability by adding new set of counters
- extends MACsec offload support to cover RoCE traffic
- dynamic completion EQs
- mlx4:
- convert to use auxiliary bus instead of custom interface
logic
- Intel
- ice:
- implement switchdev bridge offload, even for LAG
interfaces
- implement SRIOV support for LAG interfaces
- igc:
- add support for multiple in-flight TX timestamps
- Broadcom:
- bnxt:
- use the unified RX page pool buffers for XDP and non-XDP
- use the NAPI skb allocation cache
- OcteonTX2:
- support Round Robin scheduling HTB offload
- TC flower offload support for SPI field
- Freescale:
- add XDP_TX feature support
- AMD:
- ionic: add support for PCI FLR event
- sfc:
- basic conntrack offload
- introduce eth, ipv4 and ipv6 pedit offloads
- ST Microelectronics:
- stmmac: maximze PTP timestamping resolution

- Virtual NICs:
- Microsoft vNIC:
- batch ringing RX queue doorbell on receiving packets
- add page pool for RX buffers
- Virtio vNIC:
- add per queue interrupt coalescing support
- Google vNIC:
- add queue-page-list mode support

- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add port range matching tc-flower offload
- permit enslavement to netdevices with uppers

- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- convert to phylink_pcs
- Renesas:
- r8A779fx: add speed change support
- rzn1: enables vlan support

- Ethernet PHYs:
- convert mv88e6xxx to phylink_pcs

- WiFi:
- Qualcomm Wi-Fi 7 (ath12k):
- extremely High Throughput (EHT) PHY support
- RealTek (rtl8xxxu):
- enable AP mode for: RTL8192FU, RTL8710BU (RTL8188GU),
RTL8192EU and RTL8723BU
- RealTek (rtw89):
- Introduce Time Averaged SAR (TAS) support

- Connector:
- support for event filtering"

* tag 'net-next-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1806 commits)
net: ethernet: mtk_wed: minor change in wed_{tx,rx}info_show
net: ethernet: mtk_wed: add some more info in wed_txinfo_show handler
net: stmmac: clarify difference between "interface" and "phy_interface"
r8152: add vendor/device ID pair for D-Link DUB-E250
devlink: move devlink_notify_register/unregister() to dev.c
devlink: move small_ops definition into netlink.c
devlink: move tracepoint definitions into core.c
devlink: push linecard related code into separate file
devlink: push rate related code into separate file
devlink: push trap related code into separate file
devlink: use tracepoint_enabled() helper
devlink: push region related code into separate file
devlink: push param related code into separate file
devlink: push resource related code into separate file
devlink: push dpipe related code into separate file
devlink: move and rename devlink_dpipe_send_and_alloc_skb() helper
devlink: push shared buffer related code into separate file
devlink: push port related code into separate file
devlink: push object register/unregister notifications into separate helpers
inet: fix IP_TRANSPARENT error handling
...

show more ...

Merge tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:

- Documentation updates

- Miscellaneous fixes, perhaps most no

Merge tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:

- Documentation updates

- Miscellaneous fixes, perhaps most notably simplifying
SRCU_NOTIFIER_INIT() as suggested

- RCU Tasks updates, most notably treating Tasks RCU callbacks as lazy
while still treating synchronous grace periods as urgent. Also fixes
one bug that restores the ability to apply debug-objects to RCU Tasks
and another that fixes a race condition that could result in
false-positive failures of the boot-time self-test code

- RCU-scalability performance-test updates, most notably adding the
ability to measure the RCU-Tasks's grace-period kthread's CPU
consumption. This proved quite useful for the RCU Tasks work

- Reference-acquisition/release performance-test updates, including a
fix for an uninitialized wait_queue_head_t

- Miscellaneous torture-test updates

- Torture-test scripting updates, including removal of the
non-longer-functional formal-verification scripts, test builds of
individual RCU Tasks flavors, better diagnostics for loss of
connectivity for distributed rcutorture tests, disabling of reboot
loops in qemu/KVM-based rcutorture testing, and passing of init
parameters to rcutorture's init program

* tag 'rcu.2023.08.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (64 commits)
rcu: Use WRITE_ONCE() for assignments to ->next for rculist_nulls
rcu: Make the rcu_nocb_poll boot parameter usable via boot config
rcu: Mark __rcu_irq_enter_check_tick() ->rcu_urgent_qs load
srcu,notifier: Remove #ifdefs in favor of SRCU Tiny srcu_usage
rcutorture: Stop right-shifting torture_random() return values
torture: Stop right-shifting torture_random() return values
torture: Move stutter_wait() timeouts to hrtimers
torture: Move torture_shuffle() timeouts to hrtimers
torture: Move torture_onoff() timeouts to hrtimers
torture: Make torture_hrtimeout_*() use TASK_IDLE
torture: Add lock_torture writer_fifo module parameter
torture: Add a kthread-creation callback to _torture_create_kthread()
rcu-tasks: Fix boot-time RCU tasks debug-only deadlock
rcu-tasks: Permit use of debug-objects with RCU Tasks flavors
checkpatch: Complain about unexpected uses of RCU Tasks Trace
torture: Cause mkinitrd.sh to indicate failure on compile errors
torture: Make init program dump command-line arguments
torture: Switch qemu from -nographic to -display none
torture: Add init-program support for loongarch
torture: Avoid torture-test reboot loops
...

show more ...

Merge branches 'doc.2023.07.14b', 'fixes.2023.08.16a', 'rcu-tasks.2023.07.24a', 'rcuscale.2023.07.14b', 'refscale.2023.07.14b', 'torture.2023.08.14a' and 'torturescripts.2023.07.20a' into HEAD

doc.2

Merge branches 'doc.2023.07.14b', 'fixes.2023.08.16a', 'rcu-tasks.2023.07.24a', 'rcuscale.2023.07.14b', 'refscale.2023.07.14b', 'torture.2023.08.14a' and 'torturescripts.2023.07.20a' into HEAD

doc.2023.07.14b: Documentation updates.
fixes.2023.08.16a: Miscellaneous fixes.
rcu-tasks.2023.07.24a: RCU Tasks updates.
rcuscale.2023.07.14b: RCU (updater) scalability test updates.
refscale.2023.07.14b: Reference (reader) scalability test updates.
torture.2023.08.14a: Other torture-test updates.
torturescripts.2023.07.20a: Other torture-test scripting updates.

show more ...

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo V

Merge drm/drm-next into drm-intel-next

Catching-up with drm-next and drm-intel-gt-next.
It will unblock a code refactor around the platform
definitions (names vs acronyms).

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

show more ...

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/1

Merge drm/drm-next into drm-intel-gt-next

Need to pull in b3e4aae612ec ("drm/i915/hdcp: Modify hdcp_gsc_message msg sending mechanism") as
a dependency for https://patchwork.freedesktop.org/series/121735/

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

show more ...

Merge drm/drm-next into drm-misc-next

Backmerging to get v6.5-rc2.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'v6.4' into next

Sync up with mainline to bring in updates to shared infrastructure.

ASoC: Merge v6.5-rc2

Get a similar baseline to my other branches, and fixes for people using
the branch.

rcuscale: fix building with RCU_TINY

Both the CONFIG_TASKS_RCU and CONFIG_TASKS_RUDE_RCU options
are broken when RCU_TINY is enabled as well, as some functions
are missing a declaration.

In file in

rcuscale: fix building with RCU_TINY

Both the CONFIG_TASKS_RCU and CONFIG_TASKS_RUDE_RCU options
are broken when RCU_TINY is enabled as well, as some functions
are missing a declaration.

In file included from kernel/rcu/update.c:649:
kernel/rcu/tasks.h:1271:21: error: no previous prototype for 'get_rcu_tasks_rude_gp_kthread' [-Werror=missing-prototypes]
1271 | struct task_struct *get_rcu_tasks_rude_gp_kthread(void)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/rcu/rcuscale.c:330:27: error: 'get_rcu_tasks_rude_gp_kthread' undeclared here (not in a function); did you mean 'get_rcu_tasks_trace_gp_kthread'?
330 | .rso_gp_kthread = get_rcu_tasks_rude_gp_kthread,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| get_rcu_tasks_trace_gp_kthread

In file included from /home/arnd/arm-soc/kernel/rcu/update.c:649:
kernel/rcu/tasks.h:1113:21: error: no previous prototype for 'get_rcu_tasks_gp_kthread' [-Werror=missing-prototypes]
1113 | struct task_struct *get_rcu_tasks_gp_kthread(void)
| ^~~~~~~~~~~~~~~~~~~~~~~~

Also, building with CONFIG_TASKS_RUDE_RCU but not CONFIG_TASKS_RCU is
broken because of some missing stub functions:

kernel/rcu/rcuscale.c:322:27: error: 'tasks_scale_read_lock' undeclared here (not in a function); did you mean 'srcu_scale_read_lock'?
322 | .readlock = tasks_scale_read_lock,
| ^~~~~~~~~~~~~~~~~~~~~
| srcu_scale_read_lock
kernel/rcu/rcuscale.c:323:27: error: 'tasks_scale_read_unlock' undeclared here (not in a function); did you mean 'srcu_scale_read_unlock'?
323 | .readunlock = tasks_scale_read_unlock,
| ^~~~~~~~~~~~~~~~~~~~~~~
| srcu_scale_read_unlock

Move the declarations outside of the RCU_TINY #ifdef and duplicate the
shared stub functions to address all of the above.

Fixes: 88d7ff818f0ce ("rcuscale: Add RCU Tasks Rude testing")
Fixes: 755f1c5eb416b ("rcuscale: Measure RCU Tasks Trace grace-period kthread CPU time")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

show more ...

rcuscale: Add RCU Tasks Rude testing

Add a "tasks-rude" option to the rcuscale.scale_type module parameter.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

rcuscale: Measure RCU Tasks Trace grace-period kthread CPU time

This commit causes RCU Tasks Trace to output the CPU time consumed by
its grace-period kthread. The CPU time is whatever is in the de

rcuscale: Measure RCU Tasks Trace grace-period kthread CPU time

This commit causes RCU Tasks Trace to output the CPU time consumed by
its grace-period kthread. The CPU time is whatever is in the designated
task's current->stime field, and thus is controlled by whatever CPU-time
accounting scheme is in effect.

This output appears in microseconds as follows on the console:

rcu_scale: Grace-period kthread CPU time: 42367.037

[ paulmck: Apply Willy Tarreau feedback. ]

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2023-07-13

We've added 67 non-merge comm

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2023-07-13

We've added 67 non-merge commits during the last 15 day(s) which contain
a total of 106 files changed, 4444 insertions(+), 619 deletions(-).

The main changes are:

1) Fix bpftool build in presence of stale vmlinux.h,
from Alexander Lobakin.

2) Introduce bpf_me_mcache_free_rcu() and fix OOM under stress,
from Alexei Starovoitov.

3) Teach verifier actual bounds of bpf_get_smp_processor_id()
and fix perf+libbpf issue related to custom section handling,
from Andrii Nakryiko.

4) Introduce bpf map element count, from Anton Protopopov.

5) Check skb ownership against full socket, from Kui-Feng Lee.

6) Support for up to 12 arguments in BPF trampoline, from Menglong Dong.

7) Export rcu_request_urgent_qs_task, from Paul E. McKenney.

8) Fix BTF walking of unions, from Yafang Shao.

9) Extend link_info for kprobe_multi and perf_event links,
from Yafang Shao.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (67 commits)
selftests/bpf: Add selftest for PTR_UNTRUSTED
bpf: Fix an error in verifying a field in a union
selftests/bpf: Add selftests for nested_trust
bpf: Fix an error around PTR_UNTRUSTED
selftests/bpf: add testcase for TRACING with 6+ arguments
bpf, x86: allow function arguments up to 12 for TRACING
bpf, x86: save/restore regs with BPF_DW size
bpftool: Use "fallthrough;" keyword instead of comments
bpf: Add object leak check.
bpf: Convert bpf_cpumask to bpf_mem_cache_free_rcu.
bpf: Introduce bpf_mem_free_rcu() similar to kfree_rcu().
selftests/bpf: Improve test coverage of bpf_mem_alloc.
rcu: Export rcu_request_urgent_qs_task()
bpf: Allow reuse from waiting_for_gp_ttrace list.
bpf: Add a hint to allocated objects.
bpf: Change bpf_mem_cache draining process.
bpf: Further refactor alloc_bulk().
bpf: Factor out inc/dec of active flag into helpers.
bpf: Refactor alloc_bulk().
bpf: Let free_all() return the number of freed elements.
...
====================

Link: https://lore.kernel.org/r/20230714020910.80794-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

Merge branch 'bpf-mem-cache-free-rcu'

Alexei Starovoitov says:

====================
v3->v4:
- extra patch 14 from Hou to check for object leaks.
- fixed the race/leak in free_by_rcu_ttrace. Extra h

Merge branch 'bpf-mem-cache-free-rcu'

Alexei Starovoitov says:

====================
v3->v4:
- extra patch 14 from Hou to check for object leaks.
- fixed the race/leak in free_by_rcu_ttrace. Extra hunk in patch 8.
- added Acks and fixed typos.

v2->v3:
- dropped _tail optimization for free_by_rcu_ttrace
- new patch 5 to refactor inc/dec of c->active
- change 'draining' logic in patch 7
- add rcu_barrier in patch 12
- __llist_add-> llist_add(waiting_for_gp_ttrace) in patch 9 to fix race
- David's Ack in patch 13 and explanation that migrate_disable cannot be removed just yet.

v1->v2:
- Fixed race condition spotted by Hou. Patch 7.

v1:

Introduce bpf_mem_cache_free_rcu() that is similar to kfree_rcu except
the objects will go through an additional RCU tasks trace grace period
before being freed into slab.

Patches 1-9 - a bunch of prep work
Patch 10 - a patch from Paul that exports rcu_request_urgent_qs_task().
Patch 12 - the main bpf_mem_cache_free_rcu patch.
Patch 13 - use it in bpf_cpumask.

bpf_local_storage, bpf_obj_drop, qp-trie will be other users eventually.

With additional hack patch to htab that replaces bpf_mem_cache_free with bpf_mem_cache_free_rcu
the following are benchmark results:
- map_perf_test 4 8 16348 1000000
drops from 800k to 600k. Waiting for RCU GP makes objects cache cold.

- bench htab-mem -a -p 8
20% drop in performance and big increase in memory. From 3 Mbyte to 50 Mbyte. As expected.

- bench htab-mem -a -p 16 --use-case add_del_on_diff_cpu
Same performance and better memory consumption.
Before these patches this bench would OOM (with or without 'reuse after GP')
Patch 8 addresses the issue.

At the end the performance drop and additional memory consumption due to _rcu()
were expected and came out to be within reasonable margin.
Without Paul's patch 10 the memory consumption in 'bench htab-mem' is in Gbytes
which wouldn't be acceptable.

Patch 8 is a heuristic to address 'alloc on one cpu, free on another' issue.
It works well in practice. One can probably construct an artificial benchmark
to make heuristic ineffective, but we have to trade off performance, code complexity,
and memory consumption.

The life cycle of objects:
alloc: dequeue free_llist
free: enqeueu free_llist
free_llist above high watermark -> free_by_rcu_ttrace
free_rcu: enqueue free_by_rcu -> waiting_for_gp
after RCU GP waiting_for_gp -> free_by_rcu_ttrace
free_by_rcu_ttrace -> waiting_for_gp_ttrace -> slab
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

show more ...

rcu: Export rcu_request_urgent_qs_task()

If a CPU is executing a long series of non-sleeping system calls,
RCU grace periods can be delayed for on the order of a couple hundred
milliseconds. This i

rcu: Export rcu_request_urgent_qs_task()

If a CPU is executing a long series of non-sleeping system calls,
RCU grace periods can be delayed for on the order of a couple hundred
milliseconds. This is normally not a problem, but if each system call
does a call_rcu(), those callbacks can stack up. RCU will eventually
notice this callback storm, but use of rcu_request_urgent_qs_task()
allows the code invoking call_rcu() to give RCU a heads up.

This function is not for general use, not yet, anyway.

Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230706033447.54696-11-alexei.starovoitov@gmail.com

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Merge v6.5-rc1 into drm-misc-fixes

Boris needs 6.5-rc1 in drm-misc-fixes to prevent a conflict.

Signed-off-by: Maxime Ripard <mripard@kernel.org>

Merge branch 'master' into mm-hotfixes-stable

Merge tag 'rcu.2023.06.22a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:
"Documentation updates

Miscellaneous fixes, perhaps most notab

Merge tag 'rcu.2023.06.22a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

Pull RCU updates from Paul McKenney:
"Documentation updates

Miscellaneous fixes, perhaps most notably:

- Remove RCU_NONIDLE(). The new visibility of most of the idle loop
to RCU has obsoleted this API.

- Make the RCU_SOFTIRQ callback-invocation time limit also apply to
the rcuc kthreads that invoke callbacks for CONFIG_PREEMPT_RT.

- Add a jiffies-based callback-invocation time limit to handle
long-running callbacks. (The local_clock() function is only invoked
once per 32 callbacks due to its high overhead.)

- Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs, which
fixes a bug that can occur on systems with non-contiguous CPU
numbering.

kvfree_rcu updates:

- Eliminate the single-argument variant of k[v]free_rcu() now that
all uses have been converted to k[v]free_rcu_mightsleep().

- Add WARN_ON_ONCE() checks for k[v]free_rcu*() freeing callbacks too
soon. Yes, this is closing the barn door after the horse has
escaped, but Murphy says that there will be more horses.

Callback-offloading updates:

- Fix a number of bugs involving the shrinker and lazy callbacks.

Tasks RCU updates

Torture-test updates"

* tag 'rcu.2023.06.22a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (32 commits)
torture: Remove duplicated argument -enable-kvm for ppc64
doc/rcutorture: Add description of rcutorture.stall_cpu_block
rcu/rcuscale: Stop kfree_scale_thread thread(s) after unloading rcuscale
rcu/rcuscale: Move rcu_scale_*() after kfree_scale_cleanup()
rcutorture: Correct name of use_softirq module parameter
locktorture: Add long_hold to adjust lock-hold delays
rcu/nocb: Make shrinker iterate only over NOCB CPUs
rcu-tasks: Stop rcu_tasks_invoke_cbs() from using never-onlined CPUs
rcu: Make rcu_cpu_starting() rely on interrupts being disabled
rcu: Mark rcu_cpu_kthread() accesses to ->rcu_cpu_has_work
rcu: Mark additional concurrent load from ->cpu_no_qs.b.exp
rcu: Employ jiffies-based backstop to callback time limit
rcu: Check callback-invocation time limit for rcuc kthreads
rcu: Remove RCU_NONIDLE()
rcu: Add more RCU files to kernel-api.rst
rcu-tasks: Clarify the cblist_init_generic() function's pr_info() output
rcu-tasks: Avoid pr_info() with spin lock in cblist_init_generic()
rcu/nocb: Recheck lazy callbacks under the ->nocb_lock from shrinker
rcu/nocb: Fix shrinker race against callback enqueuer
rcu/nocb: Protect lazy shrinker against concurrent (de-)offloading
...

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Merge drm/drm-next into drm-misc-next-fixes

Backmerging to sync drm-misc-next-fixes with drm-misc-next.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge branch 'drm-next' of git://anongit.freedesktop.org/drm/drm into msm-next-lumag-base

Merge the drm-next tree to pick up the DRM DSC helpers (merged via
drm-intel-next tree). MSM DSC v1.2 patche

Merge branch 'drm-next' of git://anongit.freedesktop.org/drm/drm into msm-next-lumag-base

Merge the drm-next tree to pick up the DRM DSC helpers (merged via
drm-intel-next tree). MSM DSC v1.2 patches depend on these helpers.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

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