diff options
Diffstat (limited to 'Documentation/sysctl/fs.txt')
| -rw-r--r-- | Documentation/sysctl/fs.txt | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/Documentation/sysctl/fs.txt b/Documentation/sysctl/fs.txt index 819caf8ca05f..ebc679bcb2dc 100644 --- a/Documentation/sysctl/fs.txt +++ b/Documentation/sysctl/fs.txt @@ -56,26 +56,34 @@ of any kernel data structures. dentry-state: -From linux/fs/dentry.c: +From linux/include/linux/dcache.h: -------------------------------------------------------------- -struct { +struct dentry_stat_t dentry_stat { int nr_dentry; int nr_unused; int age_limit; /* age in seconds */ int want_pages; /* pages requested by system */ - int dummy[2]; -} dentry_stat = {0, 0, 45, 0,}; --------------------------------------------------------------- - -Dentries are dynamically allocated and deallocated, and -nr_dentry seems to be 0 all the time. Hence it's safe to -assume that only nr_unused, age_limit and want_pages are -used. Nr_unused seems to be exactly what its name says. + int nr_negative; /* # of unused negative dentries */ + int dummy; /* Reserved for future use */ +}; +-------------------------------------------------------------- + +Dentries are dynamically allocated and deallocated. + +nr_dentry shows the total number of dentries allocated (active ++ unused). nr_unused shows the number of dentries that are not +actively used, but are saved in the LRU list for future reuse. + Age_limit is the age in seconds after which dcache entries can be reclaimed when memory is short and want_pages is nonzero when shrink_dcache_pages() has been called and the dcache isn't pruned yet. +nr_negative shows the number of unused dentries that are also +negative dentries which do not map to any files. Instead, +they help speeding up rejection of non-existing files provided +by the users. + ============================================================== dquot-max & dquot-nr: |