Today it's only possible to write back as a page, idle, or huge. A user
might want to writeback pages which are huge and idle first as these idle
pages do not require decompression and make a good first pass for
writeback.
Idle writeback specifically has the advantage that a refault is unlikely
given that the page has been swapped for some amount of time without being
refaulted.
Huge writeback has the advantage that you're guaranteed to get the maximum
benefit from a single page writeback, that is, you're reclaiming one full
page of memory. Pages which are compressed in zram being written back
result in some benefit which is always less than a page size because of
the fact that it was compressed.
The primary use of this is for minimizing refaults in situations where the
device has to be sensitive to storage endurance. On ChromeOS we have
devices with slow eMMC and repeated writes and refaults can negatively
affect performance and endurance.
Link: https://lkml.kernel.org/r/20220322215821.1196994-1-bgeffon@google.com
Signed-off-by: Brian Geffon <bgeffon@google.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Looks like all the changes to this driver had been automated
churn since git era begun. The driver is using virt_to_bus()
so it should be updated to a proper DMA API or removed. Given
the latest "news" entry on the website is from 1999 I'm opting
for the latter.
I'm marking the allocated char device major number as [REMOVED],
I reckon we can't reuse it in case some SW out there assumes its
COSA?
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
RGB/YUV Input is sensor type and it should be sub-dev node.
To generate this dot graph
sudo modprobe vimc
media-ctl --print-dot
Signed-off-by: Kwang Son <dev.kwang.son@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Debugging of problems involving insanely long-running SMI handlers
proceeds better if the CSD-lock timeout can be adjusted. This commit
therefore provides a new smp.csd_lock_timeout kernel boot parameter
that specifies the timeout in milliseconds. The default remains at the
previously hard-coded value of five seconds.
[ paulmck: Apply feedback from Juergen Gross. ]
Cc: Rik van Riel <riel@surriel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Move some out-of-place kernel parameters into their correct
locations.
Move one out-of-order keyword/legend in kernel-parameters.rst.
Add some missing keyword legends in kernel-parameters.rst:
HIBERNATION HYPER_V
and drop some obsolete/removed keyword legends:
EIDE IOSCHED OSS TS XT
Correct the location of the setup.h file.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
x86 EFI earlyprink was removed with commit 69c1f396f2 ("efi/x86:
Convert x86 EFI earlyprintk into generic earlycon implementation").
Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
RCU-tasks stall-warning messages are printed after the grace period is ten
minutes old. Unfortunately, most of us will have rebooted the system in
response to an apparently-hung command long before the ten minutes is up,
and will thus see what looks to be a silent hang.
This commit therefore adds pr_info() messages that are printed earlier.
These should avoid being classified as errors, but should give impatient
users a hint. These are controlled by new rcupdate.rcu_task_stall_info
and rcupdate.rcu_task_stall_info_mult kernel-boot parameters. The former
defines the initial delay in jiffies (defaulting to 10 seconds) and the
latter defines the multiplier (defaulting to 3). Thus, by default, the
first message will appear 10 seconds into the RCU-tasks grace period,
the second 40 seconds in, and the third 160 seconds in. There would be
a fourth at 640 seconds in, but the stall warning message appears 600
seconds in, and once a stall warning is printed for a given grace period,
no further informational messages are printed.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit instruments the acquisitions of the srcu_struct structure's
->lock, enabling the initiation of a transition from SRCU_SIZE_SMALL
to SRCU_SIZE_BIG when sufficient contention is experienced. The
instrumentation counts the number of trylock failures within the confines
of a single jiffy. If that number exceeds the value specified by the
srcutree.small_contention_lim kernel boot parameter (which defaults to
100), and if the value specified by the srcutree.convert_to_big kernel
boot parameter has the 0x10 bit set (defaults to 0), then a transition
will be automatically initiated.
By default, there will never be any transitions, so that none of the
srcu_struct structures ever gains an srcu_node array.
The useful values for srcutree.convert_to_big are:
0x00: Never convert.
0x01: Always convert at init_srcu_struct() time.
0x02: Convert when rcutorture prints its first round of statistics.
0x03: Decide conversion approach at boot given system size.
0x10: Convert if contention is encountered.
0x12: Convert if contention is encountered or when rcutorture prints
its first round of statistics, whichever comes first.
The value 0x11 acts the same as 0x01 because the conversion happens
before there is any chance of contention.
[ paulmck: Apply "static" feedback from kernel test robot. ]
Co-developed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
This commit adds an srcu_tree.convert_to_big kernel parameter that either
refuses to convert at all (0), converts immediately at init_srcu_struct()
time (1), or lets rcutorture convert it (2). An addition contention-based
dynamic conversion choice will be added, along with documentation.
[ paulmck: Apply callback-scanning feedback from Neeraj Upadhyay. ]
Co-developed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
For debugging purposes it is very useful to have a way to see the full
contents of the SNP CPUID table provided to a guest. Add an sev=debug
kernel command-line option to do so.
Also introduce some infrastructure so that additional options can be
specified via sev=option1[,option2] over time in a consistent manner.
[ bp: Massage, simplify string parsing. ]
Suggested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220307213356.2797205-41-brijesh.singh@amd.com
Those were added as part of the SMAP enablement but SMAP is currently
an integral part of kernel proper and there's no need to disable it
anymore.
Rip out that functionality. Leave --uaccess default on for objtool as
this is what objtool should do by default anyway.
If still needed - clearcpuid=smap.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127115626.14179-4-bp@alien8.de
That chicken bit was added by
4f88651125 ("[PATCH] i386: allow disabling X86_FEATURE_SEP at boot")
but measuring int80 vsyscall performance on 32-bit doesn't matter
anymore.
If still needed, one can boot with
clearcpuid=sep
to disable that feature for testing.
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127115626.14179-3-bp@alien8.de
Having to give the X86_FEATURE array indices in order to disable a
feature bit for testing is not really user-friendly. So accept the
feature bit names too.
Some feature bits don't have names so there the array indices are still
accepted, of course.
Clearing CPUID flags is not something which should be done in production
so taint the kernel too.
An exemplary cmdline would then be something like:
clearcpuid=de,440,smca,succory,bmi1,3dnow
("succory" is wrong on purpose). And it says:
[ ... ] Clearing CPUID bits: de 13:24 smca (unknown: succory) bmi1 3dnow
[ Fix CONFIG_X86_FEATURE_NAMES=n build error as reported by the 0day
robot: https://lore.kernel.org/r/202203292206.ICsY2RKX-lkp@intel.com ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220127115626.14179-2-bp@alien8.de
Pull random number generator fixes from Jason Donenfeld:
- If a hardware random number generator passes a sufficiently large
chunk of entropy to random.c during early boot, we now skip the
"fast_init" business and let it initialize the RNG.
This makes CONFIG_RANDOM_TRUST_BOOTLOADER=y actually useful.
- We already have the command line `random.trust_cpu=0/1` option for
RDRAND, which let distros enable CONFIG_RANDOM_TRUST_CPU=y while
placating concerns of more paranoid users.
Now we add `random.trust_bootloader=0/1` so that distros can
similarly enable CONFIG_RANDOM_TRUST_BOOTLOADER=y.
- Re-add a comment that got removed by accident in the recent revert.
- Add the spec-compliant ACPI CID for vmgenid, which Microsoft added to
the vmgenid spec at Ard's request during earlier review.
- Restore build-time randomness via the latent entropy plugin, which
was lost when we transitioned to using a hash function.
* tag 'random-5.18-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
random: mix build-time latent entropy into pool at init
virt: vmgenid: recognize new CID added by Hyper-V
random: re-add removed comment about get_random_{u32,u64} reseeding
random: treat bootloader trust toggle the same way as cpu trust toggle
random: skip fast_init if hwrng provides large chunk of entropy
Pull more power management updates from Rafael Wysocki:
"These update ARM cpufreq drivers, the OPP (Operating Performance
Points) library and the power management documentation.
Specifics:
- Add per core DVFS support for QCom SoC (Bjorn Andersson), convert
to yaml binding (Manivannan Sadhasivam) and various other fixes to
the QCom drivers (Luca Weiss).
- Add OPP table for imx7s SoC (Denys Drozdov) and minor fixes (Stefan
Agner).
- Fix CPPC driver's freq/performance conversions (Pierre Gondois).
- Minor generic cleanups (Yury Norov).
- Introduce opp-microwatt property to the OPP core, bindings, etc
(Lukasz Luba).
- Convert DT bindings to schema format and various related fixes
(Yassine Oudjana).
- Expose OPP's OF node in debugfs (Viresh Kumar).
- Add Intel uncore frequency scaling documentation file to its
MAINTAINERS entry (Srinivas Pandruvada).
- Clean up the AMD P-state driver documentation (Jan Engelhardt)"
* tag 'pm-5.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (24 commits)
Documentation: amd-pstate: grammar and sentence structure updates
dt-bindings: cpufreq: cpufreq-qcom-hw: Convert to YAML bindings
dt-bindings: dvfs: Use MediaTek CPUFREQ HW as an example
Documentation: EM: Describe new registration method using DT
OPP: Add support of "opp-microwatt" for EM registration
PM: EM: add macro to set .active_power() callback conditionally
OPP: Add "opp-microwatt" supporting code
dt-bindings: opp: Add "opp-microwatt" entry in the OPP
MAINTAINERS: Add additional file to uncore frequency control
cpufreq: blocklist Qualcomm sc8280xp and sa8540p in cpufreq-dt-platdev
cpufreq: qcom-hw: Add support for per-core-dcvs
dt-bindings: power: avs: qcom,cpr: Convert to DT schema
arm64: dts: qcom: qcs404: Rename CPU and CPR OPP tables
arm64: dts: qcom: msm8996: Rename cluster OPP tables
dt-bindings: opp: Convert qcom-nvmem-cpufreq to DT schema
dt-bindings: opp: qcom-opp: Convert to DT schema
arm64: dts: qcom: msm8996-mtp: Add msm8996 compatible
dt-bindings: arm: qcom: Add msm8996 and apq8096 compatibles
opp: Expose of-node's name in debugfs
cpufreq: CPPC: Fix performance/frequency conversion
...
Merge additional power management documentation udates for 5.18-rc1:
- Add Intel uncore frequency scaling documentation file to its
MAINTAINERS entry (Srinivas Pandruvada).
- Clean up the AMD P-state driver documentation (Jan Engelhardt).
* pm-docs:
Documentation: amd-pstate: grammar and sentence structure updates
MAINTAINERS: Add additional file to uncore frequency control
Pull x86 platform driver updates from Hans de Goede:
"New drivers:
- AMD Host System Management Port (HSMP)
- Intel Software Defined Silicon
Removed drivers (functionality folded into other drivers):
- intel_cht_int33fe_microb
- surface3_button
amd-pmc:
- s2idle bug-fixes
- Support for AMD Spill to DRAM STB feature
hp-wmi:
- Fix SW_TABLET_MODE detection method (and other fixes)
- Support omen thermal profile policy v1
serial-multi-instantiate:
- Add SPI device support
- Add support for CS35L41 amplifiers used in new laptops
think-lmi:
- syfs-class-firmware-attributes Certificate authentication support
thinkpad_acpi:
- Fixes + quirks
- Add platform_profile support on AMD based ThinkPads
x86-android-tablets:
- Improve Asus ME176C / TF103C support
- Support Nextbook Ares 8, Lenovo Tab 2 830 and 1050 tablets
Lots of various other small fixes and hardware-id additions"
* tag 'platform-drivers-x86-v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (60 commits)
platform/x86: think-lmi: Certificate authentication support
Documentation: syfs-class-firmware-attributes: Lenovo Certificate support
platform/x86: amd-pmc: Only report STB errors when STB enabled
platform/x86: amd-pmc: Drop CPU QoS workaround
platform/x86: amd-pmc: Output error codes in messages
platform/x86: amd-pmc: Move to later in the suspend process
ACPI / x86: Add support for LPS0 callback handler
platform/x86: thinkpad_acpi: consistently check fan_get_status return.
platform/x86: hp-wmi: support omen thermal profile policy v1
platform/x86: hp-wmi: Changing bios_args.data to be dynamically allocated
platform/x86: hp-wmi: Fix 0x05 error code reported by several WMI calls
platform/x86: hp-wmi: Fix SW_TABLET_MODE detection method
platform/x86: hp-wmi: Fix hp_wmi_read_int() reporting error (0x05)
platform/x86: amd-pmc: Validate entry into the deepest state on resume
platform/x86: thinkpad_acpi: Don't use test_bit on an integer
platform/x86: thinkpad_acpi: Fix compiler warning about uninitialized err variable
platform/x86: thinkpad_acpi: clean up dytc profile convert
platform/x86: x86-android-tablets: Depend on EFI and SPI
platform/x86: amd-pmc: uninitialized variable in amd_pmc_s2d_init()
platform/x86: intel-uncore-freq: fix uncore_freq_common_init() error codes
...
If CONFIG_RANDOM_TRUST_CPU is set, the RNG initializes using RDRAND.
But, the user can disable (or enable) this behavior by setting
`random.trust_cpu=0/1` on the kernel command line. This allows system
builders to do reasonable things while avoiding howls from tinfoil
hatters. (Or vice versa.)
CONFIG_RANDOM_TRUST_BOOTLOADER is basically the same thing, but regards
the seed passed via EFI or device tree, which might come from RDRAND or
a TPM or somewhere else. In order to allow distros to more easily enable
this while avoiding those same howls (or vice versa), this commit adds
the corresponding `random.trust_bootloader=0/1` toggle.
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Graham Christensen <graham@grahamc.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Link: https://github.com/NixOS/nixpkgs/pull/165355
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Merge more updates from Andrew Morton:
"Various misc subsystems, before getting into the post-linux-next
material.
41 patches.
Subsystems affected by this patch series: procfs, misc, core-kernel,
lib, checkpatch, init, pipe, minix, fat, cgroups, kexec, kdump,
taskstats, panic, kcov, resource, and ubsan"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (41 commits)
Revert "ubsan, kcsan: Don't combine sanitizer with kcov on clang"
kernel/resource: fix kfree() of bootmem memory again
kcov: properly handle subsequent mmap calls
kcov: split ioctl handling into locked and unlocked parts
panic: move panic_print before kmsg dumpers
panic: add option to dump all CPUs backtraces in panic_print
docs: sysctl/kernel: add missing bit to panic_print
taskstats: remove unneeded dead assignment
kasan: no need to unset panic_on_warn in end_report()
ubsan: no need to unset panic_on_warn in ubsan_epilogue()
panic: unset panic_on_warn inside panic()
docs: kdump: add scp example to write out the dump file
docs: kdump: update description about sysfs file system support
arm64: mm: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
x86/setup: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
riscv: mm: init: use IS_ENABLED(CONFIG_KEXEC_CORE) instead of #ifdef
kexec: make crashk_res, crashk_low_res and crash_notes symbols always visible
cgroup: use irqsave in cgroup_rstat_flush_locked().
fat: use pointer to simple type in put_user()
minix: fix bug when opening a file with O_DIRECT
...
Pull networking updates from Jakub Kicinski:
"The sprinkling of SPI drivers is because we added a new one and Mark
sent us a SPI driver interface conversion pull request.
Core
----
- Introduce XDP multi-buffer support, allowing the use of XDP with
jumbo frame MTUs and combination with Rx coalescing offloads (LRO).
- Speed up netns dismantling (5x) and lower the memory cost a little.
Remove unnecessary per-netns sockets. Scope some lists to a netns.
Cut down RCU syncing. Use batch methods. Allow netdev registration
to complete out of order.
- Support distinguishing timestamp types (ingress vs egress) and
maintaining them across packet scrubbing points (e.g. redirect).
- Continue the work of annotating packet drop reasons throughout the
stack.
- Switch netdev error counters from an atomic to dynamically
allocated per-CPU counters.
- Rework a few preempt_disable(), local_irq_save() and busy waiting
sections problematic on PREEMPT_RT.
- Extend the ref_tracker to allow catching use-after-free bugs.
BPF
---
- Introduce "packing allocator" for BPF JIT images. JITed code is
marked read only, and used to be allocated at page granularity.
Custom allocator allows for more efficient memory use, lower iTLB
pressure and prevents identity mapping huge pages from getting
split.
- Make use of BTF type annotations (e.g. __user, __percpu) to enforce
the correct probe read access method, add appropriate helpers.
- Convert the BPF preload to use light skeleton and drop the
user-mode-driver dependency.
- Allow XDP BPF_PROG_RUN test infra to send real packets, enabling
its use as a packet generator.
- Allow local storage memory to be allocated with GFP_KERNEL if
called from a hook allowed to sleep.
- Introduce fprobe (multi kprobe) to speed up mass attachment (arch
bits to come later).
- Add unstable conntrack lookup helpers for BPF by using the BPF
kfunc infra.
- Allow cgroup BPF progs to return custom errors to user space.
- Add support for AF_UNIX iterator batching.
- Allow iterator programs to use sleepable helpers.
- Support JIT of add, and, or, xor and xchg atomic ops on arm64.
- Add BTFGen support to bpftool which allows to use CO-RE in kernels
without BTF info.
- Large number of libbpf API improvements, cleanups and deprecations.
Protocols
---------
- Micro-optimize UDPv6 Tx, gaining up to 5% in test on dummy netdev.
- Adjust TSO packet sizes based on min_rtt, allowing very low latency
links (data centers) to always send full-sized TSO super-frames.
- Make IPv6 flow label changes (AKA hash rethink) more configurable,
via sysctl and setsockopt. Distinguish between server and client
behavior.
- VxLAN support to "collect metadata" devices to terminate only
configured VNIs. This is similar to VLAN filtering in the bridge.
- Support inserting IPv6 IOAM information to a fraction of frames.
- Add protocol attribute to IP addresses to allow identifying where
given address comes from (kernel-generated, DHCP etc.)
- Support setting socket and IPv6 options via cmsg on ping6 sockets.
- Reject mis-use of ECN bits in IP headers as part of DSCP/TOS.
Define dscp_t and stop taking ECN bits into account in fib-rules.
- Add support for locked bridge ports (for 802.1X).
- tun: support NAPI for packets received from batched XDP buffs,
doubling the performance in some scenarios.
- IPv6 extension header handling in Open vSwitch.
- Support IPv6 control message load balancing in bonding, prevent
neighbor solicitation and advertisement from using the wrong port.
Support NS/NA monitor selection similar to existing ARP monitor.
- SMC
- improve performance with TCP_CORK and sendfile()
- support auto-corking
- support TCP_NODELAY
- MCTP (Management Component Transport Protocol)
- add user space tag control interface
- I2C binding driver (as specified by DMTF DSP0237)
- Multi-BSSID beacon handling in AP mode for WiFi.
- Bluetooth:
- handle MSFT Monitor Device Event
- add MGMT Adv Monitor Device Found/Lost events
- Multi-Path TCP:
- add support for the SO_SNDTIMEO socket option
- lots of selftest cleanups and improvements
- Increase the max PDU size in CAN ISOTP to 64 kB.
Driver API
----------
- Add HW counters for SW netdevs, a mechanism for devices which
offload packet forwarding to report packet statistics back to
software interfaces such as tunnels.
- Select the default NIC queue count as a fraction of number of
physical CPU cores, instead of hard-coding to 8.
- Expose devlink instance locks to drivers. Allow device layer of
drivers to use that lock directly instead of creating their own
which always runs into ordering issues in devlink callbacks.
- Add header/data split indication to guide user space enabling of
TCP zero-copy Rx.
- Allow configuring completion queue event size.
- Refactor page_pool to enable fragmenting after allocation.
- Add allocation and page reuse statistics to page_pool.
- Improve Multiple Spanning Trees support in the bridge to allow
reuse of topologies across VLANs, saving HW resources in switches.
- DSA (Distributed Switch Architecture):
- replay and offload of host VLAN entries
- offload of static and local FDB entries on LAG interfaces
- FDB isolation and unicast filtering
New hardware / drivers
----------------------
- Ethernet:
- LAN937x T1 PHYs
- Davicom DM9051 SPI NIC driver
- Realtek RTL8367S, RTL8367RB-VB switch and MDIO
- Microchip ksz8563 switches
- Netronome NFP3800 SmartNICs
- Fungible SmartNICs
- MediaTek MT8195 switches
- WiFi:
- mt76: MediaTek mt7916
- mt76: MediaTek mt7921u USB adapters
- brcmfmac: Broadcom BCM43454/6
- Mobile:
- iosm: Intel M.2 7360 WWAN card
Drivers
-------
- Convert many drivers to the new phylink API built for split PCS
designs but also simplifying other cases.
- Intel Ethernet NICs:
- add TTY for GNSS module for E810T device
- improve AF_XDP performance
- GTP-C and GTP-U filter offload
- QinQ VLAN support
- Mellanox Ethernet NICs (mlx5):
- support xdp->data_meta
- multi-buffer XDP
- offload tc push_eth and pop_eth actions
- Netronome Ethernet NICs (nfp):
- flow-independent tc action hardware offload (police / meter)
- AF_XDP
- Other Ethernet NICs:
- at803x: fiber and SFP support
- xgmac: mdio: preamble suppression and custom MDC frequencies
- r8169: enable ASPM L1.2 if system vendor flags it as safe
- macb/gem: ZynqMP SGMII
- hns3: add TX push mode
- dpaa2-eth: software TSO
- lan743x: multi-queue, mdio, SGMII, PTP
- axienet: NAPI and GRO support
- Mellanox Ethernet switches (mlxsw):
- source and dest IP address rewrites
- RJ45 ports
- Marvell Ethernet switches (prestera):
- basic routing offload
- multi-chain TC ACL offload
- NXP embedded Ethernet switches (ocelot & felix):
- PTP over UDP with the ocelot-8021q DSA tagging protocol
- basic QoS classification on Felix DSA switch using dcbnl
- port mirroring for ocelot switches
- Microchip high-speed industrial Ethernet (sparx5):
- offloading of bridge port flooding flags
- PTP Hardware Clock
- Other embedded switches:
- lan966x: PTP Hardward Clock
- qca8k: mdio read/write operations via crafted Ethernet packets
- Qualcomm 802.11ax WiFi (ath11k):
- add LDPC FEC type and 802.11ax High Efficiency data in radiotap
- enable RX PPDU stats in monitor co-exist mode
- Intel WiFi (iwlwifi):
- UHB TAS enablement via BIOS
- band disablement via BIOS
- channel switch offload
- 32 Rx AMPDU sessions in newer devices
- MediaTek WiFi (mt76):
- background radar detection
- thermal management improvements on mt7915
- SAR support for more mt76 platforms
- MBSSID and 6 GHz band on mt7915
- RealTek WiFi:
- rtw89: AP mode
- rtw89: 160 MHz channels and 6 GHz band
- rtw89: hardware scan
- Bluetooth:
- mt7921s: wake on Bluetooth, SCO over I2S, wide-band-speed (WBS)
- Microchip CAN (mcp251xfd):
- multiple RX-FIFOs and runtime configurable RX/TX rings
- internal PLL, runtime PM handling simplification
- improve chip detection and error handling after wakeup"
* tag 'net-next-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2521 commits)
llc: fix netdevice reference leaks in llc_ui_bind()
drivers: ethernet: cpsw: fix panic when interrupt coaleceing is set via ethtool
ice: don't allow to run ice_send_event_to_aux() in atomic ctx
ice: fix 'scheduling while atomic' on aux critical err interrupt
net/sched: fix incorrect vlan_push_eth dest field
net: bridge: mst: Restrict info size queries to bridge ports
net: marvell: prestera: add missing destroy_workqueue() in prestera_module_init()
drivers: net: xgene: Fix regression in CRC stripping
net: geneve: add missing netlink policy and size for IFLA_GENEVE_INNER_PROTO_INHERIT
net: dsa: fix missing host-filtered multicast addresses
net/mlx5e: Fix build warning, detected write beyond size of field
iwlwifi: mvm: Don't fail if PPAG isn't supported
selftests/bpf: Fix kprobe_multi test.
Revert "rethook: x86: Add rethook x86 implementation"
Revert "arm64: rethook: Add arm64 rethook implementation"
Revert "powerpc: Add rethook support"
Revert "ARM: rethook: Add rethook arm implementation"
netdevice: add missing dm_private kdoc
net: bridge: mst: prevent NULL deref in br_mst_info_size()
selftests: forwarding: Use same VRF for port and VLAN upper
...
Pull kvm updates from Paolo Bonzini:
"ARM:
- Proper emulation of the OSLock feature of the debug architecture
- Scalibility improvements for the MMU lock when dirty logging is on
- New VMID allocator, which will eventually help with SVA in VMs
- Better support for PMUs in heterogenous systems
- PSCI 1.1 support, enabling support for SYSTEM_RESET2
- Implement CONFIG_DEBUG_LIST at EL2
- Make CONFIG_ARM64_ERRATUM_2077057 default y
- Reduce the overhead of VM exit when no interrupt is pending
- Remove traces of 32bit ARM host support from the documentation
- Updated vgic selftests
- Various cleanups, doc updates and spelling fixes
RISC-V:
- Prevent KVM_COMPAT from being selected
- Optimize __kvm_riscv_switch_to() implementation
- RISC-V SBI v0.3 support
s390:
- memop selftest
- fix SCK locking
- adapter interruptions virtualization for secure guests
- add Claudio Imbrenda as maintainer
- first step to do proper storage key checking
x86:
- Continue switching kvm_x86_ops to static_call(); introduce
static_call_cond() and __static_call_ret0 when applicable.
- Cleanup unused arguments in several functions
- Synthesize AMD 0x80000021 leaf
- Fixes and optimization for Hyper-V sparse-bank hypercalls
- Implement Hyper-V's enlightened MSR bitmap for nested SVM
- Remove MMU auditing
- Eager splitting of page tables (new aka "TDP" MMU only) when dirty
page tracking is enabled
- Cleanup the implementation of the guest PGD cache
- Preparation for the implementation of Intel IPI virtualization
- Fix some segment descriptor checks in the emulator
- Allow AMD AVIC support on systems with physical APIC ID above 255
- Better API to disable virtualization quirks
- Fixes and optimizations for the zapping of page tables:
- Zap roots in two passes, avoiding RCU read-side critical
sections that last too long for very large guests backed by 4
KiB SPTEs.
- Zap invalid and defunct roots asynchronously via
concurrency-managed work queue.
- Allowing yielding when zapping TDP MMU roots in response to the
root's last reference being put.
- Batch more TLB flushes with an RCU trick. Whoever frees the
paging structure now holds RCU as a proxy for all vCPUs running
in the guest, i.e. to prolongs the grace period on their behalf.
It then kicks the the vCPUs out of guest mode before doing
rcu_read_unlock().
Generic:
- Introduce __vcalloc and use it for very large allocations that need
memcg accounting"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (246 commits)
KVM: use kvcalloc for array allocations
KVM: x86: Introduce KVM_CAP_DISABLE_QUIRKS2
kvm: x86: Require const tsc for RT
KVM: x86: synthesize CPUID leaf 0x80000021h if useful
KVM: x86: add support for CPUID leaf 0x80000021
KVM: x86: do not use KVM_X86_OP_OPTIONAL_RET0 for get_mt_mask
Revert "KVM: x86/mmu: Zap only TDP MMU leafs in kvm_zap_gfn_range()"
kvm: x86/mmu: Flush TLB before zap_gfn_range releases RCU
KVM: arm64: fix typos in comments
KVM: arm64: Generalise VM features into a set of flags
KVM: s390: selftests: Add error memop tests
KVM: s390: selftests: Add more copy memop tests
KVM: s390: selftests: Add named stages for memop test
KVM: s390: selftests: Add macro as abstraction for MEM_OP
KVM: s390: selftests: Split memop tests
KVM: s390x: fix SCK locking
RISC-V: KVM: Implement SBI HSM suspend call
RISC-V: KVM: Add common kvm_riscv_vcpu_wfi() function
RISC-V: Add SBI HSM suspend related defines
RISC-V: KVM: Implement SBI v0.3 SRST extension
...
The panic_print setting allows users to collect more information in a
panic event, like memory stats, tasks, CPUs backtraces, etc. This is an
interesting debug mechanism, but currently the print event happens *after*
kmsg_dump(), meaning that pstore, for example, cannot collect a dmesg with
the panic_print extra information.
This patch changes that in 2 steps:
(a) The panic_print setting allows to replay the existing kernel log
buffer to the console (bit 5), besides the extra information dump.
This functionality makes sense only at the end of the panic()
function. So, we hereby allow to distinguish the two situations by a
new boolean parameter in the function panic_print_sys_info().
(b) With the above change, we can safely call panic_print_sys_info()
before kmsg_dump(), allowing to dump the extra information when using
pstore or other kmsg dumpers.
The additional messages from panic_print could overwrite the oldest
messages when the buffer is full. The only reasonable solution is to use
a large enough log buffer, hence we added an advice into the kernel
parameters documentation about that.
Link: https://lkml.kernel.org/r/20220214141308.841525-1-gpiccoli@igalia.com
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Acked-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Feng Tang <feng.tang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the "panic_print" parameter/sysctl allows some interesting debug
information to be printed during a panic event. This is useful for
example in cases the user cannot kdump due to resource limits, or if the
user collects panic logs in a serial output (or pstore) and prefers a fast
reboot instead of a kdump.
Happens that currently there's no way to see all CPUs backtraces in a
panic using "panic_print" on architectures that support that. We do have
"oops_all_cpu_backtrace" sysctl, but although partially overlapping in the
functionality, they are orthogonal in nature: "panic_print" is a panic
tuning (and we have panics without oopses, like direct calls to panic() or
maybe other paths that don't go through oops_enter() function), and the
original purpose of "oops_all_cpu_backtrace" is to provide more
information on oopses for cases in which the users desire to continue
running the kernel even after an oops, i.e., used in non-panic scenarios.
So, we hereby introduce an additional bit for "panic_print" to allow
dumping the CPUs backtraces during a panic event.
Link: https://lkml.kernel.org/r/20211109202848.610874-3-gpiccoli@igalia.com
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Reviewed-by: Feng Tang <feng.tang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull media updates from Mauro Carvalho Chehab:
- a major reorg at platform Kconfig/Makefile files, organizing them per
vendor. The other media Kconfig/Makefile files also sorted
- New sensor drivers: hi847, isl7998x, ov08d10
- New Amphion vpu decoder stateful driver
- New Atmel microchip csi2dc driver
- tegra-vde driver promoted from staging
- atomisp: some fixes for it to work on BYT
- imx7-mipi-csis driver promoted from staging and renamed
- camss driver got initial support for VFE hardware version Titan 480
- mtk-vcodec has gained support for MT8192
- lots of driver changes, fixes and improvements
* tag 'media/v5.18-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (417 commits)
media: nxp: Restrict VIDEO_IMX_MIPI_CSIS to ARCH_MXC or COMPILE_TEST
media: amphion: cleanup media device if register it fail
media: amphion: fix some issues to improve robust
media: amphion: fix some error related with undefined reference to __divdi3
media: amphion: fix an issue that using pm_runtime_get_sync incorrectly
media: vidtv: use vfree() for memory allocated with vzalloc()
media: m5mols/m5mols.h: document new reset field
media: pixfmt-yuv-planar.rst: fix PIX_FMT labels
media: platform: Remove unnecessary print function dev_err()
media: amphion: Add missing of_node_put() in vpu_core_parse_dt()
media: mtk-vcodec: Add missing of_node_put() in mtk_vdec_hw_prob_done()
media: platform: amphion: Fix build error without MAILBOX
media: spi: Kconfig: Place SPI drivers on a single menu
media: i2c: Kconfig: move camera drivers to the top
media: atomisp: fix bad usage at error handling logic
media: platform: rename mediatek/mtk-jpeg/ to mediatek/jpeg/
media: media/*/Kconfig: sort entries
media: Kconfig: cleanup VIDEO_DEV dependencies
media: platform/*/Kconfig: make manufacturer menus more uniform
media: platform: Create vendor/{Makefile,Kconfig} files
...
Pull tracing updates from Steven Rostedt:
- New user_events interface. User space can register an event with the
kernel describing the format of the event. Then it will receive a
byte in a page mapping that it can check against. A privileged task
can then enable that event like any other event, which will change
the mapped byte to true, telling the user space application to start
writing the event to the tracing buffer.
- Add new "ftrace_boot_snapshot" kernel command line parameter. When
set, the tracing buffer will be saved in the snapshot buffer at boot
up when the kernel hands things over to user space. This will keep
the traces that happened at boot up available even if user space boot
up has tracing as well.
- Have TRACE_EVENT_ENUM() also update trace event field type
descriptions. Thus if a static array defines its size with an enum,
the user space trace event parsers can still know how to parse that
array.
- Add new TRACE_CUSTOM_EVENT() macro. This acts the same as the
TRACE_EVENT() macro, but will attach to an existing tracepoint. This
will make one tracepoint be able to trace different content and not
be stuck at only what the original TRACE_EVENT() macro exports.
- Fixes to tracing error logging.
- Better saving of cmdlines to PIDs when tracing (use the wakeup events
for mapping).
* tag 'trace-v5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (30 commits)
tracing: Have type enum modifications copy the strings
user_events: Add trace event call as root for low permission cases
tracing/user_events: Use alloc_pages instead of kzalloc() for register pages
tracing: Add snapshot at end of kernel boot up
tracing: Have TRACE_DEFINE_ENUM affect trace event types as well
tracing: Fix strncpy warning in trace_events_synth.c
user_events: Prevent dyn_event delete racing with ioctl add/delete
tracing: Add TRACE_CUSTOM_EVENT() macro
tracing: Move the defines to create TRACE_EVENTS into their own files
tracing: Add sample code for custom trace events
tracing: Allow custom events to be added to the tracefs directory
tracing: Fix last_cmd_set() string management in histogram code
user_events: Fix potential uninitialized pointer while parsing field
tracing: Fix allocation of last_cmd in last_cmd_set()
user_events: Add documentation file
user_events: Add sample code for typical usage
user_events: Add self-test for validator boundaries
user_events: Add self-test for perf_event integration
user_events: Add self-test for dynamic_events integration
user_events: Add self-test for ftrace integration
...
Pull printk updates from Petr Mladek:
- Make %pK behave the same as %p for kptr_restrict == 0 also with
no_hash_pointers parameter
- Ignore the default console in the device tree also when console=null
or console="" is used on the command line
- Document console=null and console="" behavior
- Prevent a deadlock and a livelock caused by console_lock in panic()
- Make console_lock available for panicking CPU
- Fast query for the next to-be-used sequence number
- Use the expected return values in printk.devkmsg __setup handler
- Use the correct atomic operations in wake_up_klogd() irq_work handler
- Avoid possible unaligned access when handling %4cc printing format
* tag 'printk-for-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
printk: fix return value of printk.devkmsg __setup handler
vsprintf: Fix %pK with kptr_restrict == 0
printk: make suppress_panic_printk static
printk: Set console_set_on_cmdline=1 when __add_preferred_console() is called with user_specified == true
Docs: printk: add 'console=null|""' to admin/kernel-parameters
printk: use atomic updates for klogd work
printk: Drop console_sem during panic
printk: Avoid livelock with heavy printk during panic
printk: disable optimistic spin during panic
printk: Add panic_in_progress helper
vsprintf: Move space out of string literals in fourcc_string()
vsprintf: Fix potential unaligned access
printk: ringbuffer: Improve prb_next_seq() performance
With the advent of various new memory types, some machines will have
multiple types of memory, e.g. DRAM and PMEM (persistent memory). The
memory subsystem of these machines can be called memory tiering system,
because the performance of the different types of memory are usually
different.
In such system, because of the memory accessing pattern changing etc,
some pages in the slow memory may become hot globally. So in this
patch, the NUMA balancing mechanism is enhanced to optimize the page
placement among the different memory types according to hot/cold
dynamically.
In a typical memory tiering system, there are CPUs, fast memory and slow
memory in each physical NUMA node. The CPUs and the fast memory will be
put in one logical node (called fast memory node), while the slow memory
will be put in another (faked) logical node (called slow memory node).
That is, the fast memory is regarded as local while the slow memory is
regarded as remote. So it's possible for the recently accessed pages in
the slow memory node to be promoted to the fast memory node via the
existing NUMA balancing mechanism.
The original NUMA balancing mechanism will stop to migrate pages if the
free memory of the target node becomes below the high watermark. This
is a reasonable policy if there's only one memory type. But this makes
the original NUMA balancing mechanism almost do not work to optimize
page placement among different memory types. Details are as follows.
It's the common cases that the working-set size of the workload is
larger than the size of the fast memory nodes. Otherwise, it's
unnecessary to use the slow memory at all. So, there are almost always
no enough free pages in the fast memory nodes, so that the globally hot
pages in the slow memory node cannot be promoted to the fast memory
node. To solve the issue, we have 2 choices as follows,
a. Ignore the free pages watermark checking when promoting hot pages
from the slow memory node to the fast memory node. This will
create some memory pressure in the fast memory node, thus trigger
the memory reclaiming. So that, the cold pages in the fast memory
node will be demoted to the slow memory node.
b. Define a new watermark called wmark_promo which is higher than
wmark_high, and have kswapd reclaiming pages until free pages reach
such watermark. The scenario is as follows: when we want to promote
hot-pages from a slow memory to a fast memory, but fast memory's free
pages would go lower than high watermark with such promotion, we wake
up kswapd with wmark_promo watermark in order to demote cold pages and
free us up some space. So, next time we want to promote hot-pages we
might have a chance of doing so.
The choice "a" may create high memory pressure in the fast memory node.
If the memory pressure of the workload is high, the memory pressure
may become so high that the memory allocation latency of the workload
is influenced, e.g. the direct reclaiming may be triggered.
The choice "b" works much better at this aspect. If the memory
pressure of the workload is high, the hot pages promotion will stop
earlier because its allocation watermark is higher than that of the
normal memory allocation. So in this patch, choice "b" is implemented.
A new zone watermark (WMARK_PROMO) is added. Which is larger than the
high watermark and can be controlled via watermark_scale_factor.
In addition to the original page placement optimization among sockets,
the NUMA balancing mechanism is extended to be used to optimize page
placement according to hot/cold among different memory types. So the
sysctl user space interface (numa_balancing) is extended in a backward
compatible way as follow, so that the users can enable/disable these
functionality individually.
The sysctl is converted from a Boolean value to a bits field. The
definition of the flags is,
- 0: NUMA_BALANCING_DISABLED
- 1: NUMA_BALANCING_NORMAL
- 2: NUMA_BALANCING_MEMORY_TIERING
We have tested the patch with the pmbench memory accessing benchmark
with the 80:20 read/write ratio and the Gauss access address
distribution on a 2 socket Intel server with Optane DC Persistent
Memory Model. The test results shows that the pmbench score can
improve up to 95.9%.
Thanks Andrew Morton to help fix the document format error.
Link: https://lkml.kernel.org/r/20220221084529.1052339-3-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: zhongjiang-ali <zhongjiang-ali@linux.alibaba.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Feng Tang <feng.tang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Free the 2nd vmemmap page associated with each HugeTLB
page", v7.
This series can minimize the overhead of struct page for 2MB HugeTLB
pages significantly. It further reduces the overhead of struct page by
12.5% for a 2MB HugeTLB compared to the previous approach, which means
2GB per 1TB HugeTLB. It is a nice gain. Comments and reviews are
welcome. Thanks.
The main implementation and details can refer to the commit log of patch
1. In this series, I have changed the following four helpers, the
following table shows the impact of the overhead of those helpers.
+------------------+-----------------------+
| APIs | head page | tail page |
+------------------+-----------+-----------+
| PageHead() | Y | N |
+------------------+-----------+-----------+
| PageTail() | Y | N |
+------------------+-----------+-----------+
| PageCompound() | N | N |
+------------------+-----------+-----------+
| compound_head() | Y | N |
+------------------+-----------+-----------+
Y: Overhead is increased.
N: Overhead is _NOT_ increased.
It shows that the overhead of those helpers on a tail page don't change
between "hugetlb_free_vmemmap=on" and "hugetlb_free_vmemmap=off". But the
overhead on a head page will be increased when "hugetlb_free_vmemmap=on"
(except PageCompound()). So I believe that Matthew Wilcox's folio series
will help with this.
The users of PageHead() and PageTail() are much less than compound_head()
and most users of PageTail() are VM_BUG_ON(), so I have done some tests
about the overhead of compound_head() on head pages.
I have tested the overhead of calling compound_head() on a head page,
which is 2.11ns (Measure the call time of 10 million times
compound_head(), and then average).
For a head page whose address is not aligned with PAGE_SIZE or a
non-compound page, the overhead of compound_head() is 2.54ns which is
increased by 20%. For a head page whose address is aligned with
PAGE_SIZE, the overhead of compound_head() is 2.97ns which is increased by
40%. Most pages are the former. I do not think the overhead is
significant since the overhead of compound_head() itself is low.
This patch (of 5):
This patch minimizes the overhead of struct page for 2MB HugeTLB pages
significantly. It further reduces the overhead of struct page by 12.5%
for a 2MB HugeTLB compared to the previous approach, which means 2GB per
1TB HugeTLB (2MB type).
After the feature of "Free sonme vmemmap pages of HugeTLB page" is
enabled, the mapping of the vmemmap addresses associated with a 2MB
HugeTLB page becomes the figure below.
HugeTLB struct pages(8 pages) page frame(8 pages)
+-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+---> PG_head
| | | 0 | -------------> | 0 |
| | +-----------+ +-----------+
| | | 1 | -------------> | 1 |
| | +-----------+ +-----------+
| | | 2 | ----------------^ ^ ^ ^ ^ ^
| | +-----------+ | | | | |
| | | 3 | ------------------+ | | | |
| | +-----------+ | | | |
| | | 4 | --------------------+ | | |
| 2MB | +-----------+ | | |
| | | 5 | ----------------------+ | |
| | +-----------+ | |
| | | 6 | ------------------------+ |
| | +-----------+ |
| | | 7 | --------------------------+
| | +-----------+
| |
| |
| |
+-----------+
As we can see, the 2nd vmemmap page frame (indexed by 1) is reused and
remaped. However, the 2nd vmemmap page frame is also can be freed to
the buddy allocator, then we can change the mapping from the figure
above to the figure below.
HugeTLB struct pages(8 pages) page frame(8 pages)
+-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+---> PG_head
| | | 0 | -------------> | 0 |
| | +-----------+ +-----------+
| | | 1 | ---------------^ ^ ^ ^ ^ ^ ^
| | +-----------+ | | | | | |
| | | 2 | -----------------+ | | | | |
| | +-----------+ | | | | |
| | | 3 | -------------------+ | | | |
| | +-----------+ | | | |
| | | 4 | ---------------------+ | | |
| 2MB | +-----------+ | | |
| | | 5 | -----------------------+ | |
| | +-----------+ | |
| | | 6 | -------------------------+ |
| | +-----------+ |
| | | 7 | ---------------------------+
| | +-----------+
| |
| |
| |
+-----------+
After we do this, all tail vmemmap pages (1-7) are mapped to the head
vmemmap page frame (0). In other words, there are more than one page
struct with PG_head associated with each HugeTLB page. We __know__ that
there is only one head page struct, the tail page structs with PG_head are
fake head page structs. We need an approach to distinguish between those
two different types of page structs so that compound_head(), PageHead()
and PageTail() can work properly if the parameter is the tail page struct
but with PG_head.
The following code snippet describes how to distinguish between real and
fake head page struct.
if (test_bit(PG_head, &page->flags)) {
unsigned long head = READ_ONCE(page[1].compound_head);
if (head & 1) {
if (head == (unsigned long)page + 1)
==> head page struct
else
==> tail page struct
} else
==> head page struct
}
We can safely access the field of the @page[1] with PG_head because the
@page is a compound page composed with at least two contiguous pages.
[songmuchun@bytedance.com: restore lost comment changes]
Link: https://lkml.kernel.org/r/20211101031651.75851-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20211101031651.75851-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During the integration of PREEMPT_RT support, the code flow around
memcg_check_events() resulted in `twisted code'. Moving the code around
and avoiding then would then lead to an additional local-irq-save
section within memcg_check_events(). While looking better, it adds a
local-irq-save section to code flow which is usually within an
local-irq-off block on non-PREEMPT_RT configurations.
The threshold event handler is a deprecated memcg v1 feature. Instead
of trying to get it to work under PREEMPT_RT just disable it. There
should be no users on PREEMPT_RT. From that perspective it makes even
less sense to get it to work under PREEMPT_RT while having zero users.
Make memory.soft_limit_in_bytes and cgroup.event_control return
-EOPNOTSUPP on PREEMPT_RT. Make an empty memcg_check_events() and
memcg_write_event_control() which return only -EOPNOTSUPP on PREEMPT_RT.
Document that the two knobs are disabled on PREEMPT_RT.
Link: https://lkml.kernel.org/r/20220226204144.1008339-3-bigeasy@linutronix.de
Suggested-by: Michal Hocko <mhocko@kernel.org>
Suggested-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: kernel test robot <oliver.sang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently memcg stats show several types of kernel memory: kernel stack,
page tables, sock, vmalloc, and slab. However, there are other
allocations with __GFP_ACCOUNT (or supersets such as GFP_KERNEL_ACCOUNT)
that are not accounted in any of those stats, a few examples are:
- various kvm allocations (e.g. allocated pages to create vcpus)
- io_uring
- tmp_page in pipes during pipe_write()
- bpf ringbuffers
- unix sockets
Keeping track of the total kernel memory is essential for the ease of
migration from cgroup v1 to v2 as there are large discrepancies between
v1's kmem.usage_in_bytes and the sum of the available kernel memory
stats in v2. Adding separate memcg stats for all __GFP_ACCOUNT kernel
allocations is an impractical maintenance burden as there a lot of those
all over the kernel code, with more use cases likely to show up in the
future.
Therefore, add a "kernel" memcg stat that is analogous to kmem page
counter, with added benefits such as using rstat infrastructure which
aggregates stats more efficiently. Additionally, this provides a
lighter alternative in case the legacy kmem is deprecated in the future
[yosryahmed@google.com: v2]
Link: https://lkml.kernel.org/r/20220203193856.972500-1-yosryahmed@google.com
Link: https://lkml.kernel.org/r/20220201200823.3283171-1-yosryahmed@google.com
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull scheduler updates from Ingo Molnar:
- Cleanups for SCHED_DEADLINE
- Tracing updates/fixes
- CPU Accounting fixes
- First wave of changes to optimize the overhead of the scheduler
build, from the fast-headers tree - including placeholder *_api.h
headers for later header split-ups.
- Preempt-dynamic using static_branch() for ARM64
- Isolation housekeeping mask rework; preperatory for further changes
- NUMA-balancing: deal with CPU-less nodes
- NUMA-balancing: tune systems that have multiple LLC cache domains per
node (eg. AMD)
- Updates to RSEQ UAPI in preparation for glibc usage
- Lots of RSEQ/selftests, for same
- Add Suren as PSI co-maintainer
* tag 'sched-core-2022-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (81 commits)
sched/headers: ARM needs asm/paravirt_api_clock.h too
sched/numa: Fix boot crash on arm64 systems
headers/prep: Fix header to build standalone: <linux/psi.h>
sched/headers: Only include <linux/entry-common.h> when CONFIG_GENERIC_ENTRY=y
cgroup: Fix suspicious rcu_dereference_check() usage warning
sched/preempt: Tell about PREEMPT_DYNAMIC on kernel headers
sched/topology: Remove redundant variable and fix incorrect type in build_sched_domains
sched/deadline,rt: Remove unused parameter from pick_next_[rt|dl]_entity()
sched/deadline,rt: Remove unused functions for !CONFIG_SMP
sched/deadline: Use __node_2_[pdl|dle]() and rb_first_cached() consistently
sched/deadline: Merge dl_task_can_attach() and dl_cpu_busy()
sched/deadline: Move bandwidth mgmt and reclaim functions into sched class source file
sched/deadline: Remove unused def_dl_bandwidth
sched/tracing: Report TASK_RTLOCK_WAIT tasks as TASK_UNINTERRUPTIBLE
sched/tracing: Don't re-read p->state when emitting sched_switch event
sched/rt: Plug rt_mutex_setprio() vs push_rt_task() race
sched/cpuacct: Remove redundant RCU read lock
sched/cpuacct: Optimize away RCU read lock
sched/cpuacct: Fix charge percpu cpuusage
sched/headers: Reorganize, clean up and optimize kernel/sched/sched.h dependencies
...
