From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 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(). ... --- .../admin-guide/cgroup-v1/blkio-controller.rst | 301 +++++++++++++++++++++ 1 file changed, 301 insertions(+) create mode 100644 Documentation/admin-guide/cgroup-v1/blkio-controller.rst (limited to 'Documentation/admin-guide/cgroup-v1/blkio-controller.rst') diff --git a/Documentation/admin-guide/cgroup-v1/blkio-controller.rst b/Documentation/admin-guide/cgroup-v1/blkio-controller.rst new file mode 100644 index 000000000..16253eda1 --- /dev/null +++ b/Documentation/admin-guide/cgroup-v1/blkio-controller.rst @@ -0,0 +1,301 @@ +=================== +Block IO Controller +=================== + +Overview +======== +cgroup subsys "blkio" implements the block io controller. There seems to be +a need of various kinds of IO control policies (like proportional BW, max BW) +both at leaf nodes as well as at intermediate nodes in a storage hierarchy. +Plan is to use the same cgroup based management interface for blkio controller +and based on user options switch IO policies in the background. + +One IO control policy is throttling policy which can be used to +specify upper IO rate limits on devices. This policy is implemented in +generic block layer and can be used on leaf nodes as well as higher +level logical devices like device mapper. + +HOWTO +===== + +Throttling/Upper Limit policy +----------------------------- +Enable Block IO controller:: + + CONFIG_BLK_CGROUP=y + +Enable throttling in block layer:: + + CONFIG_BLK_DEV_THROTTLING=y + +Mount blkio controller (see cgroups.txt, Why are cgroups needed?):: + + mount -t cgroup -o blkio none /sys/fs/cgroup/blkio + +Specify a bandwidth rate on particular device for root group. The format +for policy is ": ":: + + echo "8:16 1048576" > /sys/fs/cgroup/blkio/blkio.throttle.read_bps_device + +This will put a limit of 1MB/second on reads happening for root group +on device having major/minor number 8:16. + +Run dd to read a file and see if rate is throttled to 1MB/s or not:: + + # dd iflag=direct if=/mnt/common/zerofile of=/dev/null bs=4K count=1024 + 1024+0 records in + 1024+0 records out + 4194304 bytes (4.2 MB) copied, 4.0001 s, 1.0 MB/s + +Limits for writes can be put using blkio.throttle.write_bps_device file. + +Hierarchical Cgroups +==================== + +Throttling implements hierarchy support; however, +throttling's hierarchy support is enabled iff "sane_behavior" is +enabled from cgroup side, which currently is a development option and +not publicly available. + +If somebody created a hierarchy like as follows:: + + root + / \ + test1 test2 + | + test3 + +Throttling with "sane_behavior" will handle the +hierarchy correctly. For throttling, all limits apply +to the whole subtree while all statistics are local to the IOs +directly generated by tasks in that cgroup. + +Throttling without "sane_behavior" enabled from cgroup side will +practically treat all groups at same level as if it looks like the +following:: + + pivot + / / \ \ + root test1 test2 test3 + +Various user visible config options +=================================== + + CONFIG_BLK_CGROUP + Block IO controller. + + CONFIG_BFQ_CGROUP_DEBUG + Debug help. Right now some additional stats file show up in cgroup + if this option is enabled. + + CONFIG_BLK_DEV_THROTTLING + Enable block device throttling support in block layer. + +Details of cgroup files +======================= + +Proportional weight policy files +-------------------------------- + + blkio.bfq.weight + Specifies per cgroup weight. This is default weight of the group + on all the devices until and unless overridden by per device rule + (see `blkio.bfq.weight_device` below). + + Currently allowed range of weights is from 1 to 1000. For more details, + see Documentation/block/bfq-iosched.rst. + + blkio.bfq.weight_device + Specifes per cgroup per device weights, overriding the default group + weight. For more details, see Documentation/block/bfq-iosched.rst. + + Following is the format:: + + # echo dev_maj:dev_minor weight > blkio.bfq.weight_device + + Configure weight=300 on /dev/sdb (8:16) in this cgroup:: + + # echo 8:16 300 > blkio.bfq.weight_device + # cat blkio.bfq.weight_device + dev weight + 8:16 300 + + Configure weight=500 on /dev/sda (8:0) in this cgroup:: + + # echo 8:0 500 > blkio.bfq.weight_device + # cat blkio.bfq.weight_device + dev weight + 8:0 500 + 8:16 300 + + Remove specific weight for /dev/sda in this cgroup:: + + # echo 8:0 0 > blkio.bfq.weight_device + # cat blkio.bfq.weight_device + dev weight + 8:16 300 + + blkio.time + Disk time allocated to cgroup per device in milliseconds. First + two fields specify the major and minor number of the device and + third field specifies the disk time allocated to group in + milliseconds. + + blkio.sectors + Number of sectors transferred to/from disk by the group. First + two fields specify the major and minor number of the device and + third field specifies the number of sectors transferred by the + group to/from the device. + + blkio.io_service_bytes + Number of bytes transferred to/from the disk by the group. These + are further divided by the type of operation - read or write, sync + or async. First two fields specify the major and minor number of the + device, third field specifies the operation type and the fourth field + specifies the number of bytes. + + blkio.io_serviced + Number of IOs (bio) issued to the disk by the group. These + are further divided by the type of operation - read or write, sync + or async. First two fields specify the major and minor number of the + device, third field specifies the operation type and the fourth field + specifies the number of IOs. + + blkio.io_service_time + Total amount of time between request dispatch and request completion + for the IOs done by this cgroup. This is in nanoseconds to make it + meaningful for flash devices too. For devices with queue depth of 1, + this time represents the actual service time. When queue_depth > 1, + that is no longer true as requests may be served out of order. This + may cause the service time for a given IO to include the service time + of multiple IOs when served out of order which may result in total + io_service_time > actual time elapsed. This time is further divided by + the type of operation - read or write, sync or async. First two fields + specify the major and minor number of the device, third field + specifies the operation type and the fourth field specifies the + io_service_time in ns. + + blkio.io_wait_time + Total amount of time the IOs for this cgroup spent waiting in the + scheduler queues for service. This can be greater than the total time + elapsed since it is cumulative io_wait_time for all IOs. It is not a + measure of total time the cgroup spent waiting but rather a measure of + the wait_time for its individual IOs. For devices with queue_depth > 1 + this metric does not include the time spent waiting for service once + the IO is dispatched to the device but till it actually gets serviced + (there might be a time lag here due to re-ordering of requests by the + device). This is in nanoseconds to make it meaningful for flash + devices too. This time is further divided by the type of operation - + read or write, sync or async. First two fields specify the major and + minor number of the device, third field specifies the operation type + and the fourth field specifies the io_wait_time in ns. + + blkio.io_merged + Total number of bios/requests merged into requests belonging to this + cgroup. This is further divided by the type of operation - read or + write, sync or async. + + blkio.io_queued + Total number of requests queued up at any given instant for this + cgroup. This is further divided by the type of operation - read or + write, sync or async. + + blkio.avg_queue_size + Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. + The average queue size for this cgroup over the entire time of this + cgroup's existence. Queue size samples are taken each time one of the + queues of this cgroup gets a timeslice. + + blkio.group_wait_time + Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. + This is the amount of time the cgroup had to wait since it became busy + (i.e., went from 0 to 1 request queued) to get a timeslice for one of + its queues. This is different from the io_wait_time which is the + cumulative total of the amount of time spent by each IO in that cgroup + waiting in the scheduler queue. This is in nanoseconds. If this is + read when the cgroup is in a waiting (for timeslice) state, the stat + will only report the group_wait_time accumulated till the last time it + got a timeslice and will not include the current delta. + + blkio.empty_time + Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. + This is the amount of time a cgroup spends without any pending + requests when not being served, i.e., it does not include any time + spent idling for one of the queues of the cgroup. This is in + nanoseconds. If this is read when the cgroup is in an empty state, + the stat will only report the empty_time accumulated till the last + time it had a pending request and will not include the current delta. + + blkio.idle_time + Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. + This is the amount of time spent by the IO scheduler idling for a + given cgroup in anticipation of a better request than the existing ones + from other queues/cgroups. This is in nanoseconds. If this is read + when the cgroup is in an idling state, the stat will only report the + idle_time accumulated till the last idle period and will not include + the current delta. + + blkio.dequeue + Debugging aid only enabled if CONFIG_BFQ_CGROUP_DEBUG=y. This + gives the statistics about how many a times a group was dequeued + from service tree of the device. First two fields specify the major + and minor number of the device and third field specifies the number + of times a group was dequeued from a particular device. + + blkio.*_recursive + Recursive version of various stats. These files show the + same information as their non-recursive counterparts but + include stats from all the descendant cgroups. + +Throttling/Upper limit policy files +----------------------------------- + blkio.throttle.read_bps_device + Specifies upper limit on READ rate from the device. IO rate is + specified in bytes per second. Rules are per device. Following is + the format:: + + echo ": " > /cgrp/blkio.throttle.read_bps_device + + blkio.throttle.write_bps_device + Specifies upper limit on WRITE rate to the device. IO rate is + specified in bytes per second. Rules are per device. Following is + the format:: + + echo ": " > /cgrp/blkio.throttle.write_bps_device + + blkio.throttle.read_iops_device + Specifies upper limit on READ rate from the device. IO rate is + specified in IO per second. Rules are per device. Following is + the format:: + + echo ": " > /cgrp/blkio.throttle.read_iops_device + + blkio.throttle.write_iops_device + Specifies upper limit on WRITE rate to the device. IO rate is + specified in io per second. Rules are per device. Following is + the format:: + + echo ": " > /cgrp/blkio.throttle.write_iops_device + + Note: If both BW and IOPS rules are specified for a device, then IO is + subjected to both the constraints. + + blkio.throttle.io_serviced + Number of IOs (bio) issued to the disk by the group. These + are further divided by the type of operation - read or write, sync + or async. First two fields specify the major and minor number of the + device, third field specifies the operation type and the fourth field + specifies the number of IOs. + + blkio.throttle.io_service_bytes + Number of bytes transferred to/from the disk by the group. These + are further divided by the type of operation - read or write, sync + or async. First two fields specify the major and minor number of the + device, third field specifies the operation type and the fourth field + specifies the number of bytes. + +Common files among various policies +----------------------------------- + blkio.reset_stats + Writing an int to this file will result in resetting all the stats + for that cgroup. -- cgit v1.2.3