openSolaris 2008 - Probes - Solaris Dynamic Tracing Guide

Probes

The vminfo provider makes available probes that correspond to the fields in the vm named kernel statistic: a probe provided by vminfo fires immediately before the corresponding vm value is incremented. To display both the names and the current values of the vm named kernel statistic, use the kstat(1M) command, as shown in the following example:

$ kstat -n vm
module: cpu                             instance: 0
name:   vm                              class:    misc
        anonfree                        13
        anonpgin                        2620
        anonpgout                       13
        as_fault                        12528831
        cow_fault                       2278711
        crtime                          202.10625712
        dfree                           1328740
        execfree                        0
        execpgin                        5541
        ...

The vminfo probes are described in Table 24-1.

Table 24-1 `vminfo` Probes

`anonfree`	Probe that fires whenever an unmodified anonymous page is freed as part of paging activity. Anonymous pages are those that are not associated with a file. Memory containing such pages includes heap memory, stack memory, or memory obtained by explicitly mapping `zero`(7D).
`anonpgin`	Probe that fires whenever an anonymous page is paged in from a swap device.
`anonpgout`	Probe that fires whenever a modified anonymous page is paged out to a swap device.
`as_fault`	Probe that fires whenever a fault is taken on a page and the fault is neither a protection fault nor a copy-on-write fault.
`cow_fault`	Probe that fires whenever a copy-on-write fault is taken on a page. `arg0` contains the number of pages that are created as a result of the copy-on-write.
`dfree`	Probe that fires whenever a page is freed as a result of paging activity. Whenever `dfree` fires, exactly one of `anonfree`, `execfree` or `fsfree` will also subsequently fire.
`execfree`	Probe that fires whenever an unmodified executable page is freed as a result of paging activity.
`execpgin`	Probe that fires whenever an executable page is paged in from the backing store.
`execpgout`	Probe that fires whenever a modified executable page is paged out to the backing store. Most paging of executable pages occurs in terms of `execfree`. `execpgout` can only fire if an executable page is modified in memory, an uncommon occurrence in most systems.
`fsfree`	Probe that fires whenever an unmodified file system data page is freed as part of paging activity.
`fspgin`	Probe that fires whenever a file system page is paged in from the backing store.
`fspgout`	Probe that fires whenever a modified file system page is paged out to the backing store.
`kernel_asflt`	Probe that fires whenever a page fault is taken by the kernel on a page in its own address space. Whenever `kernel_asflt` fires, it will be immediately preceded by a firing of the `as_fault` probe.
`maj_fault`	Probe that fires whenever a page fault is taken that results in I/O from a backing store or swap device. Whenever `maj_fault` fires, it will be immediately preceded by a firing of the `pgin` probe.
`pgfrec`	Probe that fires whenever a page is reclaimed off of the free page list.
`pgin`	Probe that fires whenever a page is paged in from the backing store or from a swap device. This probe differs from `maj_fault` in that `maj_fault` only fires when a page is paged in as a result of a page fault. `pgin` fires every time a page is paged in, regardless of the reason.
`pgout`	Probe that fires whenever a page is paged out to the backing store or to a swap device.
`pgpgin`	Probe that fires whenever a page is paged in from the backing store or from a swap device. The only difference between `pgpgin` and `pgin` is that `pgpgin` contains the number of pages paged in as `arg0`. `pgin` always contains 1 in `arg0`.
`pgpgout`	Probe that fires whenever a page is paged out to the backing store or to a swap device. The only difference between `pgpgout` and `pgout` is that `pgpgout` contains the number of pages paged out as `arg0`. (`pgout` always contains 1 in `arg0`.)
`pgrec`	Probe that fires whenever a page is reclaimed.
`pgrrun`	Probe that fires whenever the pager is scheduled.
`pgswapin`	Probe that fires whenever pages from a swapped-out process are swapped in. The number of pages swapped in is contained in `arg0`.
`pgswapout`	Probe that fires whenever pages are swapped out as part of swapping out a process. The number of pages swapped out is contained in `arg0`.
`prot_fault`	Probe that fires whenever a page fault is taken due to a protection violation.
`rev`	Probe that fires whenever the page daemon begins a new revolution through all pages.
`scan`	Probe that fires whenever the page daemon examines a page.
`softlock`	Probe that fires whenever a page is faulted as a part of placing a software lock on the page.
`swapin`	Probe that fires whenever a swapped-out process is swapped back in.
`swapout`	Probe that fires whenever a process is swapped out.
`zfod`	Probe that fires whenever a zero-filled page is created on demand.

Probes

Table 24-1 vminfo Probes

Table 24-1 `vminfo` Probes