summaryrefslogtreecommitdiffstats
path: root/Documentation/IPMI.txt
diff options
context:
space:
mode:
authorJ. Bruce Fields <bfields@citi.umich.edu>2010-05-04 11:27:05 -0400
committerJ. Bruce Fields <bfields@citi.umich.edu>2010-05-04 11:29:05 -0400
commit5306293c9cd2caf41849cc909281bda628bb989e (patch)
tree3be4e8231e2772c8a43ddbef5c6a72c20b3054bb /Documentation/IPMI.txt
parentdbd65a7e44fff4741a0b2c84bd6bace85d22c242 (diff)
parent66f41d4c5c8a5deed66fdcc84509376c9a0bf9d8 (diff)
Merge commit 'v2.6.34-rc6'
Conflicts: fs/nfsd/nfs4callback.c
Diffstat (limited to 'Documentation/IPMI.txt')
-rw-r--r--Documentation/IPMI.txt12
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