having spent an age experimenting with it over the last 6 months on various
machines and with different use cases it's always either break-even or a
slight net loss for me.
- Don't need to count anonpages+filepages any more; clean+unknown+dirty for
each kind of page can be summed to get the totals.
- Track the number of free pages with a counter so that it's one less thing
for the allocator to do, which opens up further options there.
- Remove cpu_count_sync_one(). It has no users and doesn't save a whole lot.
For the cheap option, give cpu_count_sync() a boolean parameter indicating
that a cached value is okay, and rate limit the updates for cached values
to hz.
parallel, where the relevant pages are already in-core. Proposed on
tech-kern.
Temporarily disabled on MP architectures with __HAVE_UNLOCKED_PMAP until
adjustments are made to their pmaps.
fetch them when necessary. allow for fallback uses of older
time sources if others are not present.
this stops vmstat from exiting if it can't get the addresses
of these time values it often doesn't need (eg, running kernels
use the sysctl method), which has cropped up recently wit the
removal of boottime variable.
a slighly modified version of this patch (modified to handle
the old boottime variable over the new one) works against a
netbsd-9 vmstat in -current too.
XXX: pullup
bootpages is set to the pages allocated via uvm_pageboot_alloc().
poolpages is calculated from the list of pools nr_pages members.
this brings us closer to having a valid total of pages known by
the system, vs actual pages originally managed.
XXX: poolpages needs some handling for PR_RECURSIVE pools still.
in PR kern/52639, as well as some general cleaning-up...
(As proposed on tech-kern@ with additional changes and enhancements.)
Details of changes:
* All history arguments are now stored as uintmax_t values[1], both in
the kernel and in the structures used for exporting the history data
to userland via sysctl(9). This avoids problems on some architectures
where passing a 64-bit (or larger) value to printf(3) can cause it to
process the value as multiple arguments. (This can be particularly
problematic when printf()'s format string is not a literal, since in
that case the compiler cannot know how large each argument should be.)
* Update the data structures used for exporting kernel history data to
include a version number as well as the length of history arguments.
* All [2] existing users of kernhist(9) have had their format strings
updated. Each format specifier now includes an explicit length
modifier 'j' to refer to numeric values of the size of uintmax_t.
* All [2] existing users of kernhist(9) have had their format strings
updated to replace uses of "%p" with "%#jx", and the pointer
arguments are now cast to (uintptr_t) before being subsequently cast
to (uintmax_t). This is needed to avoid compiler warnings about
casting "pointer to integer of a different size."
* All [2] existing users of kernhist(9) have had instances of "%s" or
"%c" format strings replaced with numeric formats; several instances
of mis-match between format string and argument list have been fixed.
* vmstat(1) has been modified to handle the new size of arguments in the
history data as exported by sysctl(9).
* vmstat(1) now provides a warning message if the history requested with
the -u option does not exist (previously, this condition was silently
ignored, with only a single blank line being printed).
* vmstat(1) now checks the version and argument length included in the
data exported via sysctl(9) and exits if they do not match the values
with which vmstat was built.
* The kernhist(9) man-page has been updated to note the additional
requirements imposed on the format strings, along with several other
minor changes and enhancements.
[1] It would have been possible to use an explicit length (for example,
uint64_t) for the history arguments. But that would require another
"rototill" of all the users in the future when we add support for an
architecture that supports a larger size. Also, the printf(3) format
specifiers for explicitly-sized values, such as "%"PRIu64, are much
more verbose (and less aesthetically appealing, IMHO) than simply
using "%ju".
[2] I've tried very hard to find "all [the] existing users of kernhist(9)"
but it is possible that I've missed some of them. I would be glad to
update any stragglers that anyone identifies.
Disk statistics are collected in a fixed size array, that got corrupted
when a disk was detached. Adapt by skipping entries of detached disks
and detect reused disknames at the array end.
races while allowing consistent lockless sampling of the per-cpu
statistics without atomic operations. Update comment describing
the locking protocol to include this.
These files were fumble-fingered out of the last commit.
ad