X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=Documentation%2Faccounting%2Fdelay-accounting.txt;h=8a12f0730c94da018615aebc8e657daf65eadd80;hb=147db6e9474b444149238b77ceae335ca20e7b4a;hp=be215e58423b8068ac79b7f44561222195b8a3a0;hpb=d6c93e1ddde769010f9c81bbfab41a9844c0e9ba;p=linux-2.6-omap-h63xx.git diff --git a/Documentation/accounting/delay-accounting.txt b/Documentation/accounting/delay-accounting.txt index be215e58423..8a12f0730c9 100644 --- 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