cvs commit: src/sys/vm uma.h uma_core.c uma_int.h

[Robert Watson]

rwatson     2005-07-14 16:35:13 UTC

  FreeBSD src repository

  Modified files:
    sys/vm               uma.h uma_core.c uma_int.h 
  Log:
  Introduce a new sysctl, vm.zone_stats, which exports UMA(9) allocator
  statistics via a binary structure stream:
  
  - Add structure 'uma_stream_header', which defines a stream version,
    definition of MAXCPUs used in the stream, and the number of zone
    records in the stream.
  
  - Add structure 'uma_type_header', which defines the name, alignment,
    size, resource allocation limits, current pages allocated, preferred
    bucket size, and central zone + keg statistics.
  
  - Add structure 'uma_percpu_stat', which, for each per-CPU cache,
    includes the number of allocations and frees, as well as the number
    of free items in the cache.
  
  - When the sysctl is queried, return a stream header, followed by a
    series of type descriptions, each consisting of a type header
    followed by a series of MAXCPUs uma_percpu_stat structures holding
    per-CPU allocation information.  Typical values of MAXCPU will be
    1 (UP compiled kernel) and 16 (SMP compiled kernel).
  
  This query mechanism allows user space monitoring tools to extract
  memory allocation statistics in a machine-readable form, and to do so
  at a per-CPU granularity, allowing monitoring of allocation patterns
  across CPUs in order to better understand the distribution of work and
  memory flow over multiple CPUs.
  
  While here, also export the number of UMA zones as a sysctl
  vm.uma_count, in order to assist in sizing user swpace buffers to
  receive the stream.
  
  A follow-up commit of libmemstat(3), a library to monitor kernel memory
  allocation, will occur in the next few days.  This change directly
  supports converting netstat(1)'s "-mb" mode to using UMA-sourced stats
  rather than separately maintained mbuf allocator statistics.
  
  MFC after:      1 week
  
  Revision  Changes    Path
  1.23      +47 -0     src/sys/vm/uma.h
  1.122     +192 -16   src/sys/vm/uma_core.c
  1.33      +1 -1      src/sys/vm/uma_int.h