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| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2010-03-22 11:17:26 +0000 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2010-03-22 11:17:26 +0000 |
| commit | f9b44121b34174ae4f243a568393fc3225842e75 (patch) | |
| tree | 943f68cd7458d08a9e8809ed0a10b71b23911f3e /Documentation/IPMI.txt | |
| parent | 8727b909bb2348d29e62c599cd7a5d610da3760f (diff) | |
| parent | 220bf991b0366cc50a94feede3d7341fa5710ee4 (diff) | |
Merge commit 'v2.6.34-rc2' into for-2.6.34
Diffstat (limited to 'Documentation/IPMI.txt')
| -rw-r--r-- | Documentation/IPMI.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/IPMI.txt b/Documentation/IPMI.txt index bc38283379f..69dd29ed824 100644 --- a/Documentation/IPMI.txt +++ b/Documentation/IPMI.txt @@ -365,6 +365,7 @@ You can change this at module load time (for a module) with: regshifts=<shift1>,<shift2>,... slave_addrs=<addr1>,<addr2>,... force_kipmid=<enable1>,<enable2>,... + kipmid_max_busy_us=<ustime1>,<ustime2>,... unload_when_empty=[0|1] Each of these except si_trydefaults is a list, the first item for the @@ -433,6 +434,7 @@ kernel command line as: ipmi_si.regshifts=<shift1>,<shift2>,... ipmi_si.slave_addrs=<addr1>,<addr2>,... ipmi_si.force_kipmid=<enable1>,<enable2>,... + ipmi_si.kipmid_max_busy_us=<ustime1>,<ustime2>,... It works the same as the module parameters of the same names. @@ -450,6 +452,16 @@ force this thread on or off. If you force it off and don't have interrupts, the driver will run VERY slowly. Don't blame me, these interfaces suck. +Unfortunately, this thread can use a lot of CPU depending on the +interface's performance. This can waste a lot of CPU and cause +various issues with detecting idle CPU and using extra power. To +avoid this, the kipmid_max_busy_us sets the maximum amount of time, in +microseconds, that kipmid will spin before sleeping for a tick. This +value sets a balance between performance and CPU waste and needs to be +tuned to your needs. Maybe, someday, auto-tuning will be added, but +that's not a simple thing and even the auto-tuning would need to be +tuned to the user's desired performance. + The driver supports a hot add and remove of interfaces. This way, interfaces can be added or removed after the kernel is up and running. This is done using /sys/modules/ipmi_si/parameters/hotmod, which is a |