diff options
Diffstat (limited to 'Documentation/sysctl')
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 26 | ||||
| -rw-r--r-- | Documentation/sysctl/net.txt | 16 | ||||
| -rw-r--r-- | Documentation/sysctl/vm.txt | 14 |
3 files changed, 42 insertions, 14 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 6fccb69c0..f1a8333dd 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -38,6 +38,7 @@ show up in /proc/sys/kernel: - hung_task_timeout_secs - hung_task_warnings - kexec_load_disabled +- iso_cpu - kptr_restrict - kstack_depth_to_print [ X86 only ] - l2cr [ PPC only ] @@ -66,6 +67,7 @@ show up in /proc/sys/kernel: - randomize_va_space - real-root-dev ==> Documentation/initrd.txt - reboot-cmd [ SPARC only ] +- rr_interval - rtsig-max - rtsig-nr - sem @@ -384,6 +386,16 @@ kernel stack. ============================================================== +iso_cpu: (BFS CPU scheduler only). + +This sets the percentage cpu that the unprivileged SCHED_ISO tasks can +run effectively at realtime priority, averaged over a rolling five +seconds over the -whole- system, meaning all cpus. + +Set to 70 (percent) by default. + +============================================================== + l2cr: (PPC only) This flag controls the L2 cache of G3 processor boards. If @@ -723,6 +735,20 @@ rebooting. ??? ============================================================== +rr_interval: (BFS CPU scheduler only) + +This is the smallest duration that any cpu process scheduling unit +will run for. Increasing this value can increase throughput of cpu +bound tasks substantially but at the expense of increased latencies +overall. Conversely decreasing it will decrease average and maximum +latencies but at the expense of throughput. This value is in +milliseconds and the default value chosen depends on the number of +cpus available at scheduler initialisation with a minimum of 6. + +Valid values are from 1-1000. + +============================================================== + rtsig-max & rtsig-nr: The file rtsig-max can be used to tune the maximum number diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt index 6294b5186..809ab6efc 100644 --- a/Documentation/sysctl/net.txt +++ b/Documentation/sysctl/net.txt @@ -54,13 +54,15 @@ default_qdisc -------------- The default queuing discipline to use for network devices. This allows -overriding the default queue discipline of pfifo_fast with an -alternative. Since the default queuing discipline is created with the -no additional parameters so is best suited to queuing disciplines that -work well without configuration like stochastic fair queue (sfq), -CoDel (codel) or fair queue CoDel (fq_codel). Don't use queuing disciplines -like Hierarchical Token Bucket or Deficit Round Robin which require setting -up classes and bandwidths. +overriding the default of pfifo_fast with an alternative. Since the default +queuing discipline is created without additional parameters so is best suited +to queuing disciplines that work well without configuration like stochastic +fair queue (sfq), CoDel (codel) or fair queue CoDel (fq_codel). Don't use +queuing disciplines like Hierarchical Token Bucket or Deficit Round Robin +which require setting up classes and bandwidths. Note that physical multiqueue +interfaces still use mq as root qdisc, which in turn uses this default for its +leaves. Virtual devices (like e.g. lo or veth) ignore this setting and instead +default to noqueue. Default: pfifo_fast busy_read diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 9832ec52f..a4482fcea 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -225,11 +225,11 @@ with your system. To disable them, echo 4 (bit 3) into drop_caches. extfrag_threshold This parameter affects whether the kernel will compact memory or direct -reclaim to satisfy a high-order allocation. /proc/extfrag_index shows what -the fragmentation index for each order is in each zone in the system. Values -tending towards 0 imply allocations would fail due to lack of memory, -values towards 1000 imply failures are due to fragmentation and -1 implies -that the allocation will succeed as long as watermarks are met. +reclaim to satisfy a high-order allocation. The extfrag/extfrag_index file in +debugfs shows what the fragmentation index for each order is in each zone in +the system. Values tending towards 0 imply allocations would fail due to lack +of memory, values towards 1000 imply failures are due to fragmentation and -1 +implies that the allocation will succeed as long as watermarks are met. The kernel will not compact memory in a zone if the fragmentation index is <= extfrag_threshold. The default value is 500. @@ -349,7 +349,7 @@ zone[i]'s protection[j] is calculated by following expression. (i < j): zone[i]->protection[j] - = (total sums of present_pages from zone[i+1] to zone[j] on the node) + = (total sums of managed_pages from zone[i+1] to zone[j] on the node) / lowmem_reserve_ratio[i]; (i = j): (should not be protected. = 0; @@ -360,7 +360,7 @@ The default values of lowmem_reserve_ratio[i] are 256 (if zone[i] means DMA or DMA32 zone) 32 (others). As above expression, they are reciprocal number of ratio. -256 means 1/256. # of protection pages becomes about "0.39%" of total present +256 means 1/256. # of protection pages becomes about "0.39%" of total managed pages of higher zones on the node. If you would like to protect more pages, smaller values are effective. |