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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/admin-guide/laptops/disk-shock-protection.rst | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski:
"Core:
- Add dedicated kmem_cache for typical/small skb->head, avoid having
to access struct page at kfree time, and improve memory use.
- Introduce sysctl to set default RPS configuration for new netdevs.
- Define Netlink protocol specification format which can be used to
describe messages used by each family and auto-generate parsers.
Add tools for generating kernel data structures and uAPI headers.
- Expose all net/core sysctls inside netns.
- Remove 4s sleep in netpoll if carrier is instantly detected on
boot.
- Add configurable limit of MDB entries per port, and port-vlan.
- Continue populating drop reasons throughout the stack.
- Retire a handful of legacy Qdiscs and classifiers.
Protocols:
- Support IPv4 big TCP (TSO frames larger than 64kB).
- Add IP_LOCAL_PORT_RANGE socket option, to control local port range
on socket by socket basis.
- Track and report in procfs number of MPTCP sockets used.
- Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
manager.
- IPv6: don't check net.ipv6.route.max_size and rely on garbage
collection to free memory (similarly to IPv4).
- Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).
- ICMP: add per-rate limit counters.
- Add support for user scanning requests in ieee802154.
- Remove static WEP support.
- Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
reporting.
- WiFi 7 EHT channel puncturing support (client & AP).
BPF:
- Add a rbtree data structure following the "next-gen data structure"
precedent set by recently added linked list, that is, by using
kfunc + kptr instead of adding a new BPF map type.
- Expose XDP hints via kfuncs with initial support for RX hash and
timestamp metadata.
- Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
better support decap on GRE tunnel devices not operating in collect
metadata.
- Improve x86 JIT's codegen for PROBE_MEM runtime error checks.
- Remove the need for trace_printk_lock for bpf_trace_printk and
bpf_trace_vprintk helpers.
- Extend libbpf's bpf_tracing.h support for tracing arguments of
kprobes/uprobes and syscall as a special case.
- Significantly reduce the search time for module symbols by
livepatch and BPF.
- Enable cpumasks to be used as kptrs, which is useful for tracing
programs tracking which tasks end up running on which CPUs in
different time intervals.
- Add support for BPF trampoline on s390x and riscv64.
- Add capability to export the XDP features supported by the NIC.
- Add __bpf_kfunc tag for marking kernel functions as kfuncs.
- Add cgroup.memory=nobpf kernel parameter option to disable BPF
memory accounting for container environments.
Netfilter:
- Remove the CLUSTERIP target. It has been marked as obsolete for
years, and we still have WARN splats wrt races of the out-of-band
/proc interface installed by this target.
- Add 'destroy' commands to nf_tables. They are identical to the
existing 'delete' commands, but do not return an error if the
referenced object (set, chain, rule...) did not exist.
Driver API:
- Improve cpumask_local_spread() locality to help NICs set the right
IRQ affinity on AMD platforms.
- Separate C22 and C45 MDIO bus transactions more clearly.
- Introduce new DCB table to control DSCP rewrite on egress.
- Support configuration of Physical Layer Collision Avoidance (PLCA)
Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
shared medium Ethernet.
- Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
preemption of low priority frames by high priority frames.
- Add support for controlling MACSec offload using netlink SET.
- Rework devlink instance refcounts to allow registration and
de-registration under the instance lock. Split the code into
multiple files, drop some of the unnecessarily granular locks and
factor out common parts of netlink operation handling.
- Add TX frame aggregation parameters (for USB drivers).
- Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
messages with notifications for debug.
- Allow offloading of UDP NEW connections via act_ct.
- Add support for per action HW stats in TC.
- Support hardware miss to TC action (continue processing in SW from
a specific point in the action chain).
- Warn if old Wireless Extension user space interface is used with
modern cfg80211/mac80211 drivers. Do not support Wireless
Extensions for Wi-Fi 7 devices at all. Everyone should switch to
using nl80211 interface instead.
- Improve the CAN bit timing configuration. Use extack to return
error messages directly to user space, update the SJW handling,
including the definition of a new default value that will benefit
CAN-FD controllers, by increasing their oscillator tolerance.
New hardware / drivers:
- Ethernet:
- nVidia BlueField-3 support (control traffic driver)
- Ethernet support for imx93 SoCs
- Motorcomm yt8531 gigabit Ethernet PHY
- onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
- Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
- Amlogic gxl MDIO mux
- WiFi:
- RealTek RTL8188EU (rtl8xxxu)
- Qualcomm Wi-Fi 7 devices (ath12k)
- CAN:
- Renesas R-Car V4H
Drivers:
- Bluetooth:
- Set Per Platform Antenna Gain (PPAG) for Intel controllers.
- Ethernet NICs:
- Intel (1G, igc):
- support TSN / Qbv / packet scheduling features of i226 model
- Intel (100G, ice):
- use GNSS subsystem instead of TTY
- multi-buffer XDP support
- extend support for GPIO pins to E823 devices
- nVidia/Mellanox:
- update the shared buffer configuration on PFC commands
- implement PTP adjphase function for HW offset control
- TC support for Geneve and GRE with VF tunnel offload
- more efficient crypto key management method
- multi-port eswitch support
- Netronome/Corigine:
- add DCB IEEE support
- support IPsec offloading for NFP3800
- Freescale/NXP (enetc):
- support XDP_REDIRECT for XDP non-linear buffers
- improve reconfig, avoid link flap and waiting for idle
- support MAC Merge layer
- Other NICs:
- sfc/ef100: add basic devlink support for ef100
- ionic: rx_push mode operation (writing descriptors via MMIO)
- bnxt: use the auxiliary bus abstraction for RDMA
- r8169: disable ASPM and reset bus in case of tx timeout
- cpsw: support QSGMII mode for J721e CPSW9G
- cpts: support pulse-per-second output
- ngbe: add an mdio bus driver
- usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
- r8152: handle devices with FW with NCM support
- amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
- virtio-net: support multi buffer XDP
- virtio/vsock: replace virtio_vsock_pkt with sk_buff
- tsnep: XDP support
- Ethernet high-speed switches:
- nVidia/Mellanox (mlxsw):
- add support for latency TLV (in FW control messages)
- Microchip (sparx5):
- separate explicit and implicit traffic forwarding rules, make
the implicit rules always active
- add support for egress DSCP rewrite
- IS0 VCAP support (Ingress Classification)
- IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
etc.)
- ES2 VCAP support (Egress Access Control)
- support for Per-Stream Filtering and Policing (802.1Q,
8.6.5.1)
- Ethernet embedded switches:
- Marvell (mv88e6xxx):
- add MAB (port auth) offload support
- enable PTP receive for mv88e6390
- NXP (ocelot):
- support MAC Merge layer
- support for the the vsc7512 internal copper phys
- Microchip:
- lan9303: convert to PHYLINK
- lan966x: support TC flower filter statistics
- lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
- lan937x: support Credit Based Shaper configuration
- ksz9477: support Energy Efficient Ethernet
- other:
- qca8k: convert to regmap read/write API, use bulk operations
- rswitch: Improve TX timestamp accuracy
- Intel WiFi (iwlwifi):
- EHT (Wi-Fi 7) rate reporting
- STEP equalizer support: transfer some STEP (connection to radio
on platforms with integrated wifi) related parameters from the
BIOS to the firmware.
- Qualcomm 802.11ax WiFi (ath11k):
- IPQ5018 support
- Fine Timing Measurement (FTM) responder role support
- channel 177 support
- MediaTek WiFi (mt76):
- per-PHY LED support
- mt7996: EHT (Wi-Fi 7) support
- Wireless Ethernet Dispatch (WED) reset support
- switch to using page pool allocator
- RealTek WiFi (rtw89):
- support new version of Bluetooth co-existance
- Mobile:
- rmnet: support TX aggregation"
* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
page_pool: add a comment explaining the fragment counter usage
net: ethtool: fix __ethtool_dev_mm_supported() implementation
ethtool: pse-pd: Fix double word in comments
xsk: add linux/vmalloc.h to xsk.c
sefltests: netdevsim: wait for devlink instance after netns removal
selftest: fib_tests: Always cleanup before exit
net/mlx5e: Align IPsec ASO result memory to be as required by hardware
net/mlx5e: TC, Set CT miss to the specific ct action instance
net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
net/mlx5: Refactor tc miss handling to a single function
net/mlx5: Kconfig: Make tc offload depend on tc skb extension
net/sched: flower: Support hardware miss to tc action
net/sched: flower: Move filter handle initialization earlier
net/sched: cls_api: Support hardware miss to tc action
net/sched: Rename user cookie and act cookie
sfc: fix builds without CONFIG_RTC_LIB
sfc: clean up some inconsistent indentings
net/mlx4_en: Introduce flexible array to silence overflow warning
net: lan966x: Fix possible deadlock inside PTP
net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
...
Diffstat (limited to 'Documentation/admin-guide/laptops/disk-shock-protection.rst')
-rw-r--r-- | Documentation/admin-guide/laptops/disk-shock-protection.rst | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/Documentation/admin-guide/laptops/disk-shock-protection.rst b/Documentation/admin-guide/laptops/disk-shock-protection.rst new file mode 100644 index 000000000..22c7ec3e8 --- /dev/null +++ b/Documentation/admin-guide/laptops/disk-shock-protection.rst @@ -0,0 +1,151 @@ +========================== +Hard disk shock protection +========================== + +Author: Elias Oltmanns <eo@nebensachen.de> + +Last modified: 2008-10-03 + + +.. 0. Contents + + 1. Intro + 2. The interface + 3. References + 4. CREDITS + + +1. Intro +-------- + +ATA/ATAPI-7 specifies the IDLE IMMEDIATE command with unload feature. +Issuing this command should cause the drive to switch to idle mode and +unload disk heads. This feature is being used in modern laptops in +conjunction with accelerometers and appropriate software to implement +a shock protection facility. The idea is to stop all I/O operations on +the internal hard drive and park its heads on the ramp when critical +situations are anticipated. The desire to have such a feature +available on GNU/Linux systems has been the original motivation to +implement a generic disk head parking interface in the Linux kernel. +Please note, however, that other components have to be set up on your +system in order to get disk shock protection working (see +section 3. References below for pointers to more information about +that). + + +2. The interface +---------------- + +For each ATA device, the kernel exports the file +`block/*/device/unload_heads` in sysfs (here assumed to be mounted under +/sys). Access to `/sys/block/*/device/unload_heads` is denied with +-EOPNOTSUPP if the device does not support the unload feature. +Otherwise, writing an integer value to this file will take the heads +of the respective drive off the platter and block all I/O operations +for the specified number of milliseconds. When the timeout expires and +no further disk head park request has been issued in the meantime, +normal operation will be resumed. The maximal value accepted for a +timeout is 30000 milliseconds. Exceeding this limit will return +-EOVERFLOW, but heads will be parked anyway and the timeout will be +set to 30 seconds. However, you can always change a timeout to any +value between 0 and 30000 by issuing a subsequent head park request +before the timeout of the previous one has expired. In particular, the +total timeout can exceed 30 seconds and, more importantly, you can +cancel a previously set timeout and resume normal operation +immediately by specifying a timeout of 0. Values below -2 are rejected +with -EINVAL (see below for the special meaning of -1 and -2). If the +timeout specified for a recent head park request has not yet expired, +reading from `/sys/block/*/device/unload_heads` will report the number +of milliseconds remaining until normal operation will be resumed; +otherwise, reading the unload_heads attribute will return 0. + +For example, do the following in order to park the heads of drive +/dev/sda and stop all I/O operations for five seconds:: + + # echo 5000 > /sys/block/sda/device/unload_heads + +A simple:: + + # cat /sys/block/sda/device/unload_heads + +will show you how many milliseconds are left before normal operation +will be resumed. + +A word of caution: The fact that the interface operates on a basis of +milliseconds may raise expectations that cannot be satisfied in +reality. In fact, the ATA specs clearly state that the time for an +unload operation to complete is vendor specific. The hint in ATA-7 +that this will typically be within 500 milliseconds apparently has +been dropped in ATA-8. + +There is a technical detail of this implementation that may cause some +confusion and should be discussed here. When a head park request has +been issued to a device successfully, all I/O operations on the +controller port this device is attached to will be deferred. That is +to say, any other device that may be connected to the same port will +be affected too. The only exception is that a subsequent head unload +request to that other device will be executed immediately. Further +operations on that port will be deferred until the timeout specified +for either device on the port has expired. As far as PATA (old style +IDE) configurations are concerned, there can only be two devices +attached to any single port. In SATA world we have port multipliers +which means that a user-issued head parking request to one device may +actually result in stopping I/O to a whole bunch of devices. However, +since this feature is supposed to be used on laptops and does not seem +to be very useful in any other environment, there will be mostly one +device per port. Even if the CD/DVD writer happens to be connected to +the same port as the hard drive, it generally *should* recover just +fine from the occasional buffer under-run incurred by a head park +request to the HD. Actually, when you are using an ide driver rather +than its libata counterpart (i.e. your disk is called /dev/hda +instead of /dev/sda), then parking the heads of one drive (drive X) +will generally not affect the mode of operation of another drive +(drive Y) on the same port as described above. It is only when a port +reset is required to recover from an exception on drive Y that further +I/O operations on that drive (and the reset itself) will be delayed +until drive X is no longer in the parked state. + +Finally, there are some hard drives that only comply with an earlier +version of the ATA standard than ATA-7, but do support the unload +feature nonetheless. Unfortunately, there is no safe way Linux can +detect these devices, so you won't be able to write to the +unload_heads attribute. If you know that your device really does +support the unload feature (for instance, because the vendor of your +laptop or the hard drive itself told you so), then you can tell the +kernel to enable the usage of this feature for that drive by writing +the special value -1 to the unload_heads attribute:: + + # echo -1 > /sys/block/sda/device/unload_heads + +will enable the feature for /dev/sda, and giving -2 instead of -1 will +disable it again. + + +3. References +------------- + +There are several laptops from different vendors featuring shock +protection capabilities. As manufacturers have refused to support open +source development of the required software components so far, Linux +support for shock protection varies considerably between different +hardware implementations. Ideally, this section should contain a list +of pointers at different projects aiming at an implementation of shock +protection on different systems. Unfortunately, I only know of a +single project which, although still considered experimental, is fit +for use. Please feel free to add projects that have been the victims +of my ignorance. + +- https://www.thinkwiki.org/wiki/HDAPS + + See this page for information about Linux support of the hard disk + active protection system as implemented in IBM/Lenovo Thinkpads. + + +4. CREDITS +---------- + +This implementation of disk head parking has been inspired by a patch +originally published by Jon Escombe <lists@dresco.co.uk>. My efforts +to develop an implementation of this feature that is fit to be merged +into mainline have been aided by various kernel developers, in +particular by Tejun Heo and Bartlomiej Zolnierkiewicz. |