fincore
—
query in-core status of file pages
The fincore
utility queries and displays in-core status
of specified files.
Note that the result can already be stale when being output due to
other activities in the system. Thus it should be used only for advisory
purposes.
The fincore
utility accepts the following
options.
-q
- The quiet mode. Outputs nothing unless the file has in-core pages.
-s
- The summary mode. Only shows number of pages.
The following example shows that /bin/cat and
/bin/cp are fully cached in-core while the other
executables are not in-core. numbers shown in the default output are page
indexes in the file of each in-core pages.
% fincore /bin/c*
/bin/cat: 0 1 2 3
/bin/chio:
/bin/chmod:
/bin/cp: 0 1 2 3 4 5
/bin/cpio:
/bin/csh:
% fincore -s /bin/c*
/bin/cat: 4 / 4 in-core pages (100.00%)
/bin/chio: 0 / 5 in-core pages (0.00%)
/bin/chmod: 0 / 3 in-core pages (0.00%)
/bin/cp: 6 / 6 in-core pages (100.00%)
/bin/cpio: 0 / 36 in-core pages (0.00%)
/bin/csh: 0 / 41 in-core pages (0.00%)
The fincore
utility is written by
YAMAMOTO Takashi.
The concept of page cache is an implementation detail of the kernel. The
fincore
utility works using some assumptions on the
current implementation. Thus it might stop working in a future version of
NetBSD.
The amount of CPU time the current implementation of
fincore
utility would take is roughly proportional to
the file sizes. Ideally it should be proportional to the number of in-core
pages.