vminfo Probes

`vminfo` 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 kstat2 command, as shown in the following example:

$ kstat2 /system/cpu/0/vm
kstat:/system/cpu/0/vm
        anonfree                        0
        anonpgin                        0
        anonpgout                       0
        as_fault                        164243072
        cow_fault                       14804500
        crtime                          1210605854957637ns
        dfree                           0
        execfree                        0
        execpgin                        110
        execpgout                       0
        fsfree                          0

The following table describes the probes for the vminfo provider.

Table 11-40 List of vminfo Probes

Probe	Description
`anonfree`	Fires when 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`.
`anonpgin`	Fires when an anonymous page is paged in from a swap device.
`anonpgout`	Fires when a modified anonymous page is paged out to a swap device.
`as_fault`	Fires when a fault is taken on a page and the fault is neither a protection fault nor a copy-on-write fault.
`cow_fault`	Fires when 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`	Fires when 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`	Fires when an unmodified executable page is freed as a result of paging activity.
`execpgin`	Fires when an executable page is paged in from the backing store.
`execpgout`	Fires when 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`	Fires when an unmodified file system data page is freed as part of paging activity.
`fspgin`	Fires when a file system page is paged in from the backing store.
`fspgout`	Fires when a modified file system page is paged out to the backing store.
`kernel_asflt`	Fires when 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`	Fires when a page fault is taken that results in I/O from a backing store or swap device. Whenever `maj_fault` fires, it is immediately preceded by a firing of the `pgin` probe.
`pgfrec`	Fires when a page is reclaimed off of the free page list.
`pgin`	Fires when 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`	Fires when a page is paged out to the backing store or to a swap device.
`pgpgin`	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`	Fires when 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`	Fires when a page is reclaimed.
`pgrrun`	Fires when the pager is scheduled.
`pgswapin`	Fires when pages from a swapped-out process are swapped in. The number of pages swapped in is contained in `arg0`.
`pgswapout`	Fires when pages are swapped out as part of swapping out a process. The number of pages swapped out is contained in `arg0`.
`prot_fault`	Fires when a page fault is taken due to a protection violation.
`rev`	Fires when the page daemon begins a new revolution through all pages.
`scan`	Fires when the page daemon examines a page.
`softlock`	Fires when a page is faulted as a part of placing a software lock on the page.
`swapin`	Fires when a swapped-out process is swapped back in.
`swapout`	Fires when a process is swapped out.
`zfod`	Fires when a zero-filled page is created on demand.