- 'apei_estatus_for_each_section'
- 'ata_for_each_dev'
- 'ata_for_each_link'
+ - '__ata_qc_for_each'
+ - 'ata_qc_for_each'
+ - 'ata_qc_for_each_raw'
+ - 'ata_qc_for_each_with_internal'
- 'ax25_for_each'
- 'ax25_uid_for_each'
- 'bio_for_each_integrity_vec'
- 'blk_queue_for_each_rl'
- 'bond_for_each_slave'
- 'bond_for_each_slave_rcu'
+ - 'bpf_for_each_spilled_reg'
- 'btree_for_each_safe128'
- 'btree_for_each_safe32'
- 'btree_for_each_safe64'
- 'drm_atomic_crtc_for_each_plane'
- 'drm_atomic_crtc_state_for_each_plane'
- 'drm_atomic_crtc_state_for_each_plane_state'
+ - 'drm_atomic_for_each_plane_damage'
+ - 'drm_connector_for_each_possible_encoder'
- 'drm_for_each_connector_iter'
- 'drm_for_each_crtc'
- 'drm_for_each_encoder'
- 'for_each_bio'
- 'for_each_board_func_rsrc'
- 'for_each_bvec'
+ - 'for_each_card_components'
+ - 'for_each_card_links'
+ - 'for_each_card_links_safe'
+ - 'for_each_card_prelinks'
+ - 'for_each_card_rtds'
+ - 'for_each_card_rtds_safe'
+ - 'for_each_cgroup_storage_type'
- 'for_each_child_of_node'
- 'for_each_clear_bit'
- 'for_each_clear_bit_from'
- 'for_each_cmsghdr'
- 'for_each_compatible_node'
+ - 'for_each_component_dais'
+ - 'for_each_component_dais_safe'
+ - 'for_each_comp_order'
- 'for_each_console'
- 'for_each_cpu'
- 'for_each_cpu_and'
- 'for_each_cpu_wrap'
- 'for_each_dev_addr'
- 'for_each_dma_cap_mask'
+ - 'for_each_dpcm_be'
+ - 'for_each_dpcm_be_rollback'
+ - 'for_each_dpcm_be_safe'
+ - 'for_each_dpcm_fe'
- 'for_each_drhd_unit'
- 'for_each_dss_dev'
- 'for_each_efi_memory_desc'
- 'for_each_iommu'
- 'for_each_ip_tunnel_rcu'
- 'for_each_irq_nr'
+ - 'for_each_link_codecs'
- 'for_each_lru'
- 'for_each_matching_node'
- 'for_each_matching_node_and_match'
- 'for_each_mem_range_rev'
- 'for_each_migratetype_order'
- 'for_each_msi_entry'
+ - 'for_each_msi_entry_safe'
- 'for_each_net'
- 'for_each_netdev'
- 'for_each_netdev_continue'
- 'for_each_node_with_property'
- 'for_each_of_allnodes'
- 'for_each_of_allnodes_from'
+ - 'for_each_of_cpu_node'
- 'for_each_of_pci_range'
- 'for_each_old_connector_in_state'
- 'for_each_old_crtc_in_state'
- 'for_each_oldnew_connector_in_state'
- 'for_each_oldnew_crtc_in_state'
- 'for_each_oldnew_plane_in_state'
+ - 'for_each_oldnew_plane_in_state_reverse'
- 'for_each_oldnew_private_obj_in_state'
- 'for_each_old_plane_in_state'
- 'for_each_old_private_obj_in_state'
- 'for_each_process'
- 'for_each_process_thread'
- 'for_each_property_of_node'
+ - 'for_each_registered_fb'
- 'for_each_reserved_mem_region'
- - 'for_each_resv_unavail_range'
+ - 'for_each_rtd_codec_dai'
+ - 'for_each_rtd_codec_dai_rollback'
- 'for_each_rtdcom'
- 'for_each_rtdcom_safe'
- 'for_each_set_bit'
- 'for_each_set_bit_from'
- 'for_each_sg'
- 'for_each_sg_page'
+ - 'for_each_sibling_event'
- '__for_each_thread'
- 'for_each_thread'
- 'for_each_zone'
- 'hlist_nulls_for_each_entry_from'
- 'hlist_nulls_for_each_entry_rcu'
- 'hlist_nulls_for_each_entry_safe'
+ - 'i3c_bus_for_each_i2cdev'
+ - 'i3c_bus_for_each_i3cdev'
- 'ide_host_for_each_port'
- 'ide_port_for_each_dev'
- 'ide_port_for_each_present_dev'
- 'kvm_for_each_memslot'
- 'kvm_for_each_vcpu'
- 'list_for_each'
+ - 'list_for_each_codec'
+ - 'list_for_each_codec_safe'
- 'list_for_each_entry'
- 'list_for_each_entry_continue'
- 'list_for_each_entry_continue_rcu'
- 'list_for_each_entry_continue_reverse'
- 'list_for_each_entry_from'
+ - 'list_for_each_entry_from_rcu'
- 'list_for_each_entry_from_reverse'
- 'list_for_each_entry_lockless'
- 'list_for_each_entry_rcu'
- 'media_device_for_each_intf'
- 'media_device_for_each_link'
- 'media_device_for_each_pad'
+ - 'nanddev_io_for_each_page'
- 'netdev_for_each_lower_dev'
- 'netdev_for_each_lower_private'
- 'netdev_for_each_lower_private_rcu'
- 'sk_nulls_for_each'
- 'sk_nulls_for_each_from'
- 'sk_nulls_for_each_rcu'
+ - 'snd_array_for_each'
- 'snd_pcm_group_for_each_entry'
- 'snd_soc_dapm_widget_for_each_path'
- 'snd_soc_dapm_widget_for_each_path_safe'
- 'snd_soc_dapm_widget_for_each_sink_path'
- 'snd_soc_dapm_widget_for_each_source_path'
- 'tb_property_for_each'
+ - 'tcf_exts_for_each_action'
- 'udp_portaddr_for_each_entry'
- 'udp_portaddr_for_each_entry_rcu'
- 'usb_hub_for_each_child'
- 'v4l2_m2m_for_each_dst_buf_safe'
- 'v4l2_m2m_for_each_src_buf'
- 'v4l2_m2m_for_each_src_buf_safe'
+ - 'virtio_device_for_each_vq'
+ - 'xa_for_each'
+ - 'xas_for_each'
+ - 'xas_for_each_conflict'
+ - 'xas_for_each_marked'
- 'zorro_for_each_dev'
#IncludeBlocks: Preserve # Unknown to clang-format-5.0
size in 512B sectors of the zones of the device, with
the eventual exception of the last zone of the device
which may be smaller.
+
+What: /sys/block/<disk>/queue/io_timeout
+Date: November 2018
+Contact: Weiping Zhang <zhangweiping@didiglobal.com>
+Description:
+ io_timeout is the request timeout in milliseconds. If a request
+ does not complete in this time then the block driver timeout
+ handler is invoked. That timeout handler can decide to retry
+ the request, to fail it or to start a device recovery strategy.
statistics (bd_count, bd_reads, bd_writes) in a format
similar to block layer statistics file format.
+What: /sys/block/zram<id>/writeback_limit_enable
+Date: November 2018
+Contact: Minchan Kim <minchan@kernel.org>
+Description:
+ The writeback_limit_enable file is read-write and specifies
+ eanbe of writeback_limit feature. "1" means eable the feature.
+ No limit "0" is the initial state.
+
What: /sys/block/zram<id>/writeback_limit
Date: November 2018
Contact: Minchan Kim <minchan@kernel.org>
Description:
The writeback_limit file is read-write and specifies the maximum
amount of writeback ZRAM can do. The limit could be changed
- in run time and "0" means disable the limit.
- No limit is the initial state.
+ in run time.
than maximum throughput. In these cases, consider setting the
strict_guarantees parameter.
+slice_idle_us
+-------------
+
+Controls the same tuning parameter as slice_idle, but in microseconds.
+Either tunable can be used to set idling behavior. Afterwards, the
+other tunable will reflect the newly set value in sysfs.
+
strict_guarantees
-----------------
zoned=[0/1]: Default: 0
0: Block device is exposed as a random-access block device.
- 1: Block device is exposed as a host-managed zoned block device.
+ 1: Block device is exposed as a host-managed zoned block device. Requires
+ CONFIG_BLK_DEV_ZONED.
zone_size=[MB]: Default: 256
Per zone size when exposed as a zoned block device. Must be a power of two.
IO to sleep for this amount of microseconds before entering classic
polling.
+io_timeout (RW)
+---------------
+io_timeout is the request timeout in milliseconds. If a request does not
+complete in this time then the block driver timeout handler is invoked.
+That timeout handler can decide to retry the request, to fail it or to start
+a device recovery strategy.
+
iostats (RW)
-------------
This file is used to control (on/off) the iostats accounting of the
A brief description of exported device attributes. For more details please
read Documentation/ABI/testing/sysfs-block-zram.
-Name access description
----- ------ -----------
-disksize RW show and set the device's disk size
-initstate RO shows the initialization state of the device
-reset WO trigger device reset
-mem_used_max WO reset the `mem_used_max' counter (see later)
-mem_limit WO specifies the maximum amount of memory ZRAM can use
- to store the compressed data
-writeback_limit WO specifies the maximum amount of write IO zram can
- write out to backing device as 4KB unit
-max_comp_streams RW the number of possible concurrent compress operations
-comp_algorithm RW show and change the compression algorithm
-compact WO trigger memory compaction
-debug_stat RO this file is used for zram debugging purposes
-backing_dev RW set up backend storage for zram to write out
-idle WO mark allocated slot as idle
+Name access description
+---- ------ -----------
+disksize RW show and set the device's disk size
+initstate RO shows the initialization state of the device
+reset WO trigger device reset
+mem_used_max WO reset the `mem_used_max' counter (see later)
+mem_limit WO specifies the maximum amount of memory ZRAM can use
+ to store the compressed data
+writeback_limit WO specifies the maximum amount of write IO zram can
+ write out to backing device as 4KB unit
+writeback_limit_enable RW show and set writeback_limit feature
+max_comp_streams RW the number of possible concurrent compress operations
+comp_algorithm RW show and change the compression algorithm
+compact WO trigger memory compaction
+debug_stat RO this file is used for zram debugging purposes
+backing_dev RW set up backend storage for zram to write out
+idle WO mark allocated slot as idle
User space is advised to use the following files to read the device statistics.
If there are lots of write IO with flash device, potentially, it has
flash wearout problem so that admin needs to design write limitation
to guarantee storage health for entire product life.
-To overcome the concern, zram supports "writeback_limit".
-The "writeback_limit"'s default value is 0 so that it doesn't limit
-any writeback. If admin want to measure writeback count in a certain
-period, he could know it via /sys/block/zram0/bd_stat's 3rd column.
+
+To overcome the concern, zram supports "writeback_limit" feature.
+The "writeback_limit_enable"'s default value is 0 so that it doesn't limit
+any writeback. IOW, if admin want to apply writeback budget, he should
+enable writeback_limit_enable via
+
+ $ echo 1 > /sys/block/zramX/writeback_limit_enable
+
+Once writeback_limit_enable is set, zram doesn't allow any writeback
+until admin set the budget via /sys/block/zramX/writeback_limit.
+
+(If admin doesn't enable writeback_limit_enable, writeback_limit's value
+assigned via /sys/block/zramX/writeback_limit is meaninless.)
If admin want to limit writeback as per-day 400M, he could do it
like below.
- MB_SHIFT=20
- 4K_SHIFT=12
- echo $((400<<MB_SHIFT>>4K_SHIFT)) > \
- /sys/block/zram0/writeback_limit.
+ $ MB_SHIFT=20
+ $ 4K_SHIFT=12
+ $ echo $((400<<MB_SHIFT>>4K_SHIFT)) > \
+ /sys/block/zram0/writeback_limit.
+ $ echo 1 > /sys/block/zram0/writeback_limit_enable
-If admin want to allow further write again, he could do it like below
+If admin want to allow further write again once the bugdet is exausted,
+he could do it like below
- echo 0 > /sys/block/zram0/writeback_limit
+ $ echo $((400<<MB_SHIFT>>4K_SHIFT)) > \
+ /sys/block/zram0/writeback_limit
If admin want to see remaining writeback budget since he set,
- cat /sys/block/zram0/writeback_limit
+ $ cat /sys/block/zramX/writeback_limit
+
+If admin want to disable writeback limit, he could do
+
+ $ echo 0 > /sys/block/zramX/writeback_limit_enable
The writeback_limit count will reset whenever you reset zram(e.g.,
system reboot, echo 1 > /sys/block/zramX/reset) so keeping how many of
writeback happened until you reset the zram to allocate extra writeback
budget in next setting is user's job.
+If admin want to measure writeback count in a certain period, he could
+know it via /sys/block/zram0/bd_stat's 3rd column.
+
= memory tracking
With CONFIG_ZRAM_MEMORY_TRACKING, user can know information of the
------------------------------
A: YES. BPF instructions, arguments to BPF programs, set of helper
functions and their arguments, recognized return codes are all part
-of ABI. However when tracing programs are using bpf_probe_read() helper
-to walk kernel internal datastructures and compile with kernel
-internal headers these accesses can and will break with newer
-kernels. The union bpf_attr -> kern_version is checked at load time
-to prevent accidentally loading kprobe-based bpf programs written
-for a different kernel. Networking programs don't do kern_version check.
+of ABI. However there is one specific exception to tracing programs
+which are using helpers like bpf_probe_read() to walk kernel internal
+data structures and compile with kernel internal headers. Both of these
+kernel internals are subject to change and can break with newer kernels
+such that the program needs to be adapted accordingly.
Q: How much stack space a BPF program uses?
-------------------------------------------
Sometimes you need to ensure that a subsequent call to :c:func:`xa_store`
will not need to allocate memory. The :c:func:`xa_reserve` function
-will store a reserved entry at the indicated index. Users of the normal
-API will see this entry as containing ``NULL``. If you do not need to
-use the reserved entry, you can call :c:func:`xa_release` to remove the
-unused entry. If another user has stored to the entry in the meantime,
-:c:func:`xa_release` will do nothing; if instead you want the entry to
-become ``NULL``, you should use :c:func:`xa_erase`.
+will store a reserved entry at the indicated index. Users of the
+normal API will see this entry as containing ``NULL``. If you do
+not need to use the reserved entry, you can call :c:func:`xa_release`
+to remove the unused entry. If another user has stored to the entry
+in the meantime, :c:func:`xa_release` will do nothing; if instead you
+want the entry to become ``NULL``, you should use :c:func:`xa_erase`.
+Using :c:func:`xa_insert` on a reserved entry will fail.
If all entries in the array are ``NULL``, the :c:func:`xa_empty` function
will return ``true``.
* :c:func:`xa_store_bh`
* :c:func:`xa_store_irq`
* :c:func:`xa_insert`
+ * :c:func:`xa_insert_bh`
+ * :c:func:`xa_insert_irq`
* :c:func:`xa_erase`
* :c:func:`xa_erase_bh`
* :c:func:`xa_erase_irq`
===========================================
[1] ARM Linux Kernel documentation - CPUs bindings
- Documentation/devicetree/bindings/arm/cpus.txt
+ Documentation/devicetree/bindings/arm/cpus.yaml
===========================================
[1] ARM Linux Kernel documentation - CPUs bindings
- Documentation/devicetree/bindings/arm/cpus.txt
+ Documentation/devicetree/bindings/arm/cpus.yaml
[2] ARM Linux Kernel documentation - PSCI bindings
Documentation/devicetree/bindings/arm/psci.txt
Required properties:
- compatible: standard compatible string for a Primecell peripheral,
- see Documentation/devicetree/bindings/arm/primecell.txt
+ see Documentation/devicetree/bindings/arm/primecell.yaml
for more details
should be: "arm,sp810", "arm,primecell"
===============================================================================
[1] ARM Linux kernel documentation
- Documentation/devicetree/bindings/arm/cpus.txt
+ Documentation/devicetree/bindings/arm/cpus.yaml
Each clock is assigned an identifier and client nodes use this identifier
to specify the clock which they consume.
-All these identifier could be found in <dt-bindings/clock/marvell-mmp2.h>.
+All these identifiers could be found in <dt-bindings/clock/marvell,mmp2.h>.
* ARM PrimeCell Color LCD Controller PL110/PL111
-See also Documentation/devicetree/bindings/arm/primecell.txt
+See also Documentation/devicetree/bindings/arm/primecell.yaml
Required properties:
reg = <0x04300000 0x20000>;
reg-names = "kgsl_3d0_reg_memory";
interrupts = <GIC_SPI 80 0>;
- interrupt-names = "kgsl_3d0_irq";
clock-names =
"core",
"iface",
"marvell,armada-8k-gpio" should be used for the Armada 7K and 8K
SoCs (either from AP or CP), see
- Documentation/devicetree/bindings/arm/marvell/cp110-system-controller0.txt
- and
Documentation/devicetree/bindings/arm/marvell/ap806-system-controller.txt
for specific details about the offset property.
PPI affinity can be expressed as a single "ppi-partitions" node,
containing a set of sub-nodes, each with the following property:
- affinity: Should be a list of phandles to CPU nodes (as described in
-Documentation/devicetree/bindings/arm/cpus.txt).
+ Documentation/devicetree/bindings/arm/cpus.yaml).
GICv3 has one or more Interrupt Translation Services (ITS) that are
used to route Message Signalled Interrupts (MSI) to the CPUs.
git.samba.org / sfrench / cifs-2.6.git / commitdiff