Commit Graph

17 Commits

Author SHA1 Message Date
Robert Watson
10b037c1d9 Update copyright for 2006.
MFC after:	3 days
2006-02-11 19:21:39 +00:00
Robert Watson
1d90b80f28 The uma_zone data structure defines the size of its uz_cpu[] array as 1,
but then sizes the containing data structure at run-time to make room
for per-cpu cache data.  Modify libmemstat to separately allocate a
buffer to hold per-cpu cache data, sized based on the run-time mp_maxid
variable when using libkvm to access UMA data.  This avoids reading
invalid cache data from beyond the end of the uma_zone data structure
on the stack, which can result in invalid statistics and/or reads from
invalid kernel addresses.

Foot target practice by:	ps
MFC after:			3 days
2006-02-11 19:19:29 +00:00
Robert Watson
59e012a852 When reporting an error reading from UMA per-cpu cache pointers using KVM,
return a KVM error rather than an out of memory error, so that the caller
reports the KVM error state.  This replaces a misleading error message
with a more accurate although equally confusing one.

MFC after:	3 days
2006-02-11 18:55:03 +00:00
Robert Watson
3f374960e6 Read all_cpus variable out of kmem, and validate CPUs against the all_cpus
cpu mask before looking at the cache entries for the CPU.  For systems
with sparse CPU id arrays, this skips otherwise uninitialized cache
structures.

MFC after:	3 days
2006-02-11 18:44:37 +00:00
Robert Watson
ee4be9485c Correct a typo in the extraction of zone information from UMA using kmem:
bytes = allocated - freed, not bytes = allocated = freed.

MFC after:	3 days
2006-02-11 16:54:00 +00:00
Robert Watson
c21f7757d2 Remove unnecessary and undesirable 'static' from function-local keg
list, which could cause problems for multi-threaded applications
using libmemstat to monitor UMA in more than one thread
simultaneously.

MFC after:	3 days
2006-01-16 00:37:20 +00:00
Robert Watson
2286854ff0 Define LIBMEMSTAT so that vm_page.h won't perform a nested include of
opt_vmpage.h.

Remove definition of _KERNEL, it is no longer required in order to
include uma_int.h, as the sensitive parts of uma_int.h (a number of
inlines depending on kernel-only constants) are now protected by
_KERNEL.
2005-08-04 10:06:39 +00:00
Robert Watson
33c20d188c Add memstat_kvm_uma(), an implementation of a libmemstat(3) query routine
that knows how to extract UMA(9) allocator statistics from a core dump or
live memory image using kvm(3).  The caller is expected to provide the
necessary kvm_t handle, which is then used by libmemstat(3).

With these changes, it is trivially straight forward to re-introduce
vmstat -z support on core dumps, which was lost when UMA was introduced.

In the short term, this requires including vm/ include files that are not
intended for extra-kernel use, requiring in turn some ugliness.
2005-08-01 19:07:39 +00:00
Robert Watson
22247a2a38 Correct two libmemstat(3) bugs:
- Move memory_type_list flushing logic from memstat_mtl_free() to
  _memstat_mtl_empty(), a libmemstat-internal function that can
  be called from other parts of the library.  Invoke
  _memstat_mtl_empty() from memstat_mtl_free(), which also frees
  the containing list structure.

  Invoke _memstat_mtl_empty() instead of memstat_mtl_free() in
  various error cases in memstat_malloc.c and memstat_uma.c, which
  previously resulted in the list being freed prematurely.

- Reverse the order of updating the mt_kegfree and mt_free fields
  of the memory_type in memstat_uma.c, otherwise keg free items
  won't be counted properly for non-secondary zones.

MFC after:	3 days
2005-08-01 13:18:21 +00:00
Robert Watson
7f6e27372b If a retrieved UMA zone is a secondary zone, don't report keg free items,
as they actually belong to the  primary zone, and maye otherwise be
reported more than once.

MFC after:	1 day
2005-07-25 09:52:59 +00:00
Robert Watson
345628080d Introduce more formal error handling for libmemstat(3):
- Define a set of libmemstat(3) error constants, which are used by all
  libmemstat(3) methods except for memstat_mtl_alloc(), which allocates
  a memory type list and may return ENOMEM via errno.

- Define a per-memory_type_list current error value, which is set when a
  call associated with a memory list fails.  This requires wrapping a
  structure around the queue(9) list head data structure, but this change
  is not visible to libmemstat(3) consumers due to using access methods.

- Add a new accessor method, memstat_mtl_geterror() to retrieve the error
  number.

- Consistently set the error number in a number of failure modes where
  previously some combination of setting errno and printf'ing error
  descriptions was used.  libmemstat(3) will now no longer print to stdio
  under any circumstances.  Returns of NULL/-1 for errors remain the
  same.

This avoids use of stdio, misuse of error numbers, and should make it
easier to program a libmemstat(3) consumer able to print useful error
messages.  Currently, no error-to-string function is provided, as I'm
unsure how to address internationalization concerns.

MFC after:	1 day
2005-07-24 01:28:54 +00:00
Robert Watson
ddefbc898a Prefix two non-static libmemstat(3) internal functions with '_' symbols, to
try and discourage use outside the library.

Remove duplicate declaration of memstat_mtl_free() from memstat_internal.h,
as it's not internal, and the memstat.h definition suffices.
2005-07-23 21:17:15 +00:00
Robert Watson
ca108fe268 UMA supports "secondary" zones, in which a second zone can be layered
on top of a primary zone, sharing the same allocation "keg".  When
reporting statistics for zones, do not report the free items in the
keg as part of the free items in the zone, or those free items will
be reported more than once: for the primary zone, and then any
secondary zones off the primary zone.  Separately record and maintain
a kegfree statistic, and export via memstat_get_kegfree(), which is
available for use if needed.  Since items free'd back to the keg are
not fully initialized, and hence may not actually be available (since
secondary zone ctor-time initialization can fail), this makes some
amount of sense.

This change corrects a bug made visible in the libmemstat(3)
modifications to netstat: mbufs freed back to the keg from the
packet zone would be counted twice, resulting in negative values
being printed in the mbuf free count.

Some further refinement of reporting relating to secondary zones may
still be required.

Reported by:	ssouhlal
MFC after:	3 days
2005-07-20 09:17:40 +00:00
Robert Watson
d144359bde Teach libmemstat(3) about UMA(9) failure statistics.
Requested by:	victor cruceru <victor dot cruceru at gmail dot com>
MFC after:	1 week
2005-07-15 23:39:21 +00:00
Robert Watson
3ab4da680f Re-spell wronge less wrongly as wrong.
Submitted by:	jkoshy
MFC after:	1 week
2005-07-15 10:13:50 +00:00
Robert Watson
37b40e499e Properly combine per-CPU UMA cache allocation and free counts with the
global counters maintained in the zone.

MFC after:	1 week
2005-07-14 20:01:04 +00:00
Robert Watson
0cddce4989 Add libmemstat(3), a library for use by debugging and monitoring
applications in tracking kernel memory statistics.  It provides an
abstracted interface to uma(9) and malloc(9) statistics, wrapped
around the recently added binary stream sysctls for the allocators.

Using this interface, it is easy to build monitoring tools, query
specific memory types for usage information, etc.  Facilities are
provided for binding caller-provided data to memory types,
incremental updates of memory types, and queries that span multiple
allocators.

Support for additional allocators is (relatively) easy to add.

The API for libmemstat(3) will probably change some over time as
consumers are written, and requirements evolve.  It is written to
avoid encoding ABIs for data structure layout into consuming
applications for this reason.

MFC after:	1 week
2005-07-14 17:40:02 +00:00