diff options
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/bcache.rst | 13 | ||||
| -rw-r--r-- | Documentation/admin-guide/blockdev/zoned_loop.rst | 61 | ||||
| -rw-r--r-- | Documentation/admin-guide/md.rst | 10 | ||||
| -rw-r--r-- | Documentation/admin-guide/sysctl/net.rst | 29 |
4 files changed, 76 insertions, 37 deletions
diff --git a/Documentation/admin-guide/bcache.rst b/Documentation/admin-guide/bcache.rst index 6fdb495ac466..f71f349553e4 100644 --- a/Documentation/admin-guide/bcache.rst +++ b/Documentation/admin-guide/bcache.rst @@ -17,8 +17,7 @@ The latest bcache kernel code can be found from mainline Linux kernel: It's designed around the performance characteristics of SSDs - it only allocates in erase block sized buckets, and it uses a hybrid btree/log to track cached extents (which can be anywhere from a single sector to the bucket size). It's -designed to avoid random writes at all costs; it fills up an erase block -sequentially, then issues a discard before reusing it. +designed to avoid random writes at all costs. Both writethrough and writeback caching are supported. Writeback defaults to off, but can be switched on and off arbitrarily at runtime. Bcache goes to @@ -618,19 +617,11 @@ bucket_size cache_replacement_policy One of either lru, fifo or random. -discard - Boolean; if on a discard/TRIM will be issued to each bucket before it is - reused. Defaults to off, since SATA TRIM is an unqueued command (and thus - slow). - freelist_percent Size of the freelist as a percentage of nbuckets. Can be written to to increase the number of buckets kept on the freelist, which lets you artificially reduce the size of the cache at runtime. Mostly for testing - purposes (i.e. testing how different size caches affect your hit rate), but - since buckets are discarded when they move on to the freelist will also make - the SSD's garbage collection easier by effectively giving it more reserved - space. + purposes (i.e. testing how different size caches affect your hit rate). io_errors Number of errors that have occurred, decayed by io_error_halflife. diff --git a/Documentation/admin-guide/blockdev/zoned_loop.rst b/Documentation/admin-guide/blockdev/zoned_loop.rst index 64dcfde7450a..806adde664db 100644 --- a/Documentation/admin-guide/blockdev/zoned_loop.rst +++ b/Documentation/admin-guide/blockdev/zoned_loop.rst @@ -68,30 +68,43 @@ The options available for the add command can be listed by reading the In more details, the options that can be used with the "add" command are as follows. -================ =========================================================== -id Device number (the X in /dev/zloopX). - Default: automatically assigned. -capacity_mb Device total capacity in MiB. This is always rounded up to - the nearest higher multiple of the zone size. - Default: 16384 MiB (16 GiB). -zone_size_mb Device zone size in MiB. Default: 256 MiB. -zone_capacity_mb Device zone capacity (must always be equal to or lower than - the zone size. Default: zone size. -conv_zones Total number of conventioanl zones starting from sector 0. - Default: 8. -base_dir Path to the base directory where to create the directory - containing the zone files of the device. - Default=/var/local/zloop. - The device directory containing the zone files is always - named with the device ID. E.g. the default zone file - directory for /dev/zloop0 is /var/local/zloop/0. -nr_queues Number of I/O queues of the zoned block device. This value is - always capped by the number of online CPUs - Default: 1 -queue_depth Maximum I/O queue depth per I/O queue. - Default: 64 -buffered_io Do buffered IOs instead of direct IOs (default: false) -================ =========================================================== +=================== ========================================================= +id Device number (the X in /dev/zloopX). + Default: automatically assigned. +capacity_mb Device total capacity in MiB. This is always rounded up + to the nearest higher multiple of the zone size. + Default: 16384 MiB (16 GiB). +zone_size_mb Device zone size in MiB. Default: 256 MiB. +zone_capacity_mb Device zone capacity (must always be equal to or lower + than the zone size. Default: zone size. +conv_zones Total number of conventioanl zones starting from + sector 0 + Default: 8 +base_dir Path to the base directory where to create the directory + containing the zone files of the device. + Default=/var/local/zloop. + The device directory containing the zone files is always + named with the device ID. E.g. the default zone file + directory for /dev/zloop0 is /var/local/zloop/0. +nr_queues Number of I/O queues of the zoned block device. This + value is always capped by the number of online CPUs + Default: 1 +queue_depth Maximum I/O queue depth per I/O queue. + Default: 64 +buffered_io Do buffered IOs instead of direct IOs (default: false) +zone_append Enable or disable a zloop device native zone append + support. + Default: 1 (enabled). + If native zone append support is disabled, the block layer + will emulate this operation using regular write + operations. +ordered_zone_append Enable zloop mitigation of zone append reordering. + Default: disabled. + This is useful for testing file systems file data mapping + (extents), as when enabled, this can significantly reduce + the number of data extents needed to for a file data + mapping. +=================== ========================================================= 3) Deleting a Zoned Device -------------------------- diff --git a/Documentation/admin-guide/md.rst b/Documentation/admin-guide/md.rst index deed823eab01..dc7eab191caa 100644 --- a/Documentation/admin-guide/md.rst +++ b/Documentation/admin-guide/md.rst @@ -238,6 +238,16 @@ All md devices contain: the number of devices in a raid4/5/6, or to support external metadata formats which mandate such clipping. + logical_block_size + Configure the array's logical block size in bytes. This attribute + is only supported for 1.x meta. Write the value before starting + array. The final array LBS uses the maximum between this + configuration and LBS of all combined devices. Note that + LBS cannot exceed PAGE_SIZE before RAID supports folio. + WARNING: Arrays created on new kernel cannot be assembled at old + kernel due to padding check, Set module parameter 'check_new_feature' + to false to bypass, but data loss may occur. + reshape_position This is either ``none`` or a sector number within the devices of the array where ``reshape`` is up to. If this is set, the three diff --git a/Documentation/admin-guide/sysctl/net.rst b/Documentation/admin-guide/sysctl/net.rst index 2ef50828aff1..369a738a6819 100644 --- a/Documentation/admin-guide/sysctl/net.rst +++ b/Documentation/admin-guide/sysctl/net.rst @@ -212,6 +212,14 @@ mem_pcpu_rsv Per-cpu reserved forward alloc cache size in page units. Default 1MB per CPU. +bypass_prot_mem +--------------- + +Skip charging socket buffers to the global per-protocol memory +accounting controlled by net.ipv4.tcp_mem, net.ipv4.udp_mem, etc. + +Default: 0 (off) + rmem_default ------------ @@ -347,9 +355,9 @@ skb_defer_max ------------- Max size (in skbs) of the per-cpu list of skbs being freed -by the cpu which allocated them. Used by TCP stack so far. +by the cpu which allocated them. -Default: 64 +Default: 128 optmem_max ---------- @@ -406,6 +414,23 @@ to SOCK_TXREHASH_DEFAULT (i. e. not overridden by setsockopt). If set to 1 (default), hash rethink is performed on listening socket. If set to 0, hash rethink is not performed. +txq_reselection_ms +------------------ + +Controls how often (in ms) a busy connected flow can select another tx queue. + +A resection is desirable when/if user thread has migrated and XPS +would select a different queue. Same can occur without XPS +if the flow hash has changed. + +But switching txq can introduce reorders, especially if the +old queue is under high pressure. Modern TCP stacks deal +well with reorders if they happen not too often. + +To disable this feature, set the value to 0. + +Default : 1000 + gro_normal_batch ---------------- |