Merge branch 'pci-for-jesse' of git://git.kernel.org/pub/scm/linux/kernel/git/tip...

[sfrench/cifs-2.6.git] / Documentation / accounting / delay-accounting.txt

diff --git a/Documentation/accounting/delay-accounting.txt b/Documentation/accounting/delay-accounting.txt
index be215e58423b8068ac79b7f44561222195b8a3a0..8a12f0730c94da018615aebc8e657daf65eadd80 100644 (file)
--- a/Documentation/accounting/delay-accounting.txt
+++ b/Documentation/accounting/delay-accounting.txt
@@ -11,6 +11,7 @@ the delays experienced by a task while
 a) waiting for a CPU (while being runnable)
 b) completion of synchronous block I/O initiated by the task
 c) swapping in pages
+d) memory reclaim
 
 and makes these statistics available to userspace through
 the taskstats interface.
@@ -41,7 +42,7 @@ this structure. See
      include/linux/taskstats.h
 for a description of the fields pertaining to delay accounting.
 It will generally be in the form of counters returning the cumulative
-delay seen for cpu, sync block I/O, swapin etc.
+delay seen for cpu, sync block I/O, swapin, memory reclaim etc.
 
 Taking the difference of two successive readings of a given
 counter (say cpu_delay_total) for a task will give the delay
@@ -64,11 +65,13 @@ Compile the kernel with
        CONFIG_TASK_DELAY_ACCT=y
        CONFIG_TASKSTATS=y
 
-Enable the accounting at boot time by adding
-the following to the kernel boot options
-       delayacct
+Delay accounting is enabled by default at boot up.
+To disable, add
+   nodelayacct
+to the kernel boot options. The rest of the instructions
+below assume this has not been done.
 
-and after the system has booted up, use a utility
+After the system has booted up, use a utility
 similar to  getdelays.c to access the delays
 seen by a given task or a task group (tgid).
 The utility also allows a given command to be
@@ -92,7 +95,9 @@ CPU   count   real total      virtual total   delay total
        7876    92005750        100000000       24001500
 IO     count   delay total
        0       0
-MEM    count   delay total
+SWAP   count   delay total
+       0       0
+RECLAIM        count   delay total
        0       0
 
 Get delays seen in executing a given simple command
@@ -106,5 +111,7 @@ CPU count   real total      virtual total   delay total
        6       4000250         4000000         0
 IO     count   delay total
        0       0
-MEM    count   delay total
+SWAP   count   delay total
+       0       0
+RECLAIM        count   delay total
        0       0