Provided by: flashcache-utils_3.1.3+git20150701-2ubuntu2_i386 bug

NAME

       flashcache_setioctl   -   Set  I/O  behavior  for  special  process  in
       flashcache

DESCRIPTION

       The flashcache_setioctl command can be used  to  set/remove  a  process
       from    flashcache    blacklist/whitelist,    or    clear    flashcache
       blacklist/whitelist.

SYNOPSIS

       flashcache_setioctl (-c | -a | -r) (-b pid |-w pid) ssd_devname

OPTIONS

       -c     Clear blacklist/whitelist

       -a     Add to blacklist/whitelist

       -r     Remove from blacklist/whitelist

       -b     Operate on blacklist

       -w     Operate on whitelist

FLASHCACHE CACHE POLICY

       Flashcache can be put in one of 2 modes -  Cache  Everything  or  Cache
       Nothing   (dev.flashcache.cache_all).    The   defaults  is  to  "cache
       everything".

       These 2 modes have a blacklist and a whitelist.

       The tgid (thread group id) for a group of pthreads can  be  used  as  a
       shorthand to tag all threads in an application.  The tgid for a pthread
       is returned by getpid()  and  the  pid  of  the  individual  thread  is
       returned by gettid().

       The algorithm works as follows :

       In "cache everything" mode, 1) If the pid of the process issuing the IO
       is in the blacklist, do not cache the IO.  ELSE, 2) If the tgid  is  in
       the  blacklist,  don't  cache this IO.  UNLESS 3) The particular pid is
       marked as an exception (and entered in the whitelist, which  makes  the
       IO  cacheable).   4) Finally, even if IO is cacheable up to this point,
       skip sequential IO if configured by the sysctl.

       Conversely, in "cache nothing" mode, 1)  If  the  pid  of  the  process
       issuing the IO is in the whitelist, cache the IO.  ELSE, 2) If the tgid
       is in the whitelist, cache this IO.  UNLESS 3) The  particular  pid  is
       marked  as  an exception (and entered in the blacklist, which makes the
       IO non-cacheable).  4) Anything whitelisted is  cached,  regardless  of
       sequential or random IO.

SEE ALSO

       flashcache_create(8)

       README and other documents in /usr/share/doc/flashcache-utils

       The flashcache source code and all documentation may be downloaded from
       <https://github.com/facebook/flashcache/>.

AUTHORS

       Flashcache is developed by Mohan Srinivasan <mohan@fb.com>

       This man page was written by Liang Guo <guoliang@debian.org> for Debian
       GNU/Linux (but may be used by others).