avc_cache_stats(3)                  SELinux API documentation                  avc_cache_stats(3)



NAME
       avc_cache_stats, avc_av_stats, avc_sid_stats - obtain userspace SELinux AVC statistics

SYNOPSIS
       #include <selinux/selinux.h>
       #include <selinux/avc.h>

       void avc_av_stats(void);

       void avc_sid_stats(void);

       void avc_cache_stats(struct avc_cache_stats *stats);

DESCRIPTION
       The  userspace  AVC maintains two internal hash tables, one to store security ID's and one
       to cache access decisions.

       avc_av_stats() and avc_sid_stats() produce log  messages  indicating  the  status  of  the
       access  decision and SID tables, respectively.  The messages contain the number of entries
       in the table, number of hash buckets and number of buckets used,  and  maximum  number  of
       entries in a single bucket.

       avc_cache_stats() populates a structure whose fields reflect cache activity:

              struct avc_cache_stats {
                  unsigned  entry_lookups;
                  unsigned  entry_hits;
                  unsigned  entry_misses;
                  unsigned  entry_discards;
                  unsigned  cav_lookups;
                  unsigned  cav_hits;
                  unsigned  cav_probes;
                  unsigned  cav_misses;
              };


       entry_lookups
              Number of queries made.

       entry_hits
              Number of times a decision was found in the aeref argument.

       entry_misses
              Number of times a decision was not found in the aeref argument.

       entry_discards
              Number  of times a decision was not found in the aeref argument and the aeref argu‐
              ment was non-NULL.

       cav_lookups
              Number of cache lookups.

       cav_hits
              Number of cache hits.

       cav_misses
              Number of cache misses.

       cav_probes
              Number of entries examined while searching the cache.

NOTES
       When the cache is flushed as a result of a call to avc_reset() or a policy change  notifi‐
       cation,  the  statistics  returned by avc_cache_stats() are reset to zero.  The SID table,
       however, is left unchanged.

       When a policy change notification is received, a call to avc_av_stats() is made before the
       cache is flushed.

AUTHOR
       Eamon Walsh <ewalsh AT tycho.gov>

SEE ALSO
       avc_init(3), avc_has_perm(3), avc_context_to_sid(3), avc_add_callback(3), selinux(8)



                                           27 May 2004                         avc_cache_stats(3)