• Neil Horman's avatar
    xfrm: select sane defaults for xfrm[4|6] gc_thresh · a33bc5c1
    Neil Horman authored
    Choose saner defaults for xfrm[4|6] gc_thresh values on init
    Currently, the xfrm[4|6] code has hard-coded initial gc_thresh values
    (set to 1024).  Given that the ipv4 and ipv6 routing caches are sized
    dynamically at boot time, the static selections can be non-sensical.
    This patch dynamically selects an appropriate gc threshold based on
    the corresponding main routing table size, using the assumption that
    we should in the worst case be able to handle as many connections as
    the routing table can.
    For ipv4, the maximum route cache size is 16 * the number of hash
    buckets in the route cache.  Given that xfrm4 starts garbage
    collection at the gc_thresh and prevents new allocations at 2 *
    gc_thresh, we set gc_thresh to half the maximum route cache size.
    For ipv6, its a bit trickier.  there is no maximum route cache size,
    but the ipv6 dst_ops gc_thresh is statically set to 1024.  It seems
    sane to select a simmilar gc_thresh for the xfrm6 code that is half
    the number of hash buckets in the v6 route cache times 16 (like the v4
    code does).
    Signed-off-by: default avatarNeil Horman <nhorman@tuxdriver.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
ip6_fib.h 4.88 KB