diff options
Diffstat (limited to 'sys/kern/kern_mbuf.c')
| -rw-r--r-- | sys/kern/kern_mbuf.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c index 0648a5d..a864c94 100644 --- a/sys/kern/kern_mbuf.c +++ b/sys/kern/kern_mbuf.c @@ -32,11 +32,14 @@ __FBSDID("$FreeBSD$"); #include <sys/param.h> #include <sys/malloc.h> +#include <sys/types.h> #include <sys/systm.h> #include <sys/mbuf.h> #include <sys/domain.h> #include <sys/eventhandler.h> #include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/mutex.h> #include <sys/protosw.h> #include <sys/smp.h> #include <sys/sysctl.h> @@ -272,6 +275,12 @@ uma_zone_t zone_jumbo16; uma_zone_t zone_ext_refcnt; /* + * Callout to assist us in freeing mbufs. + */ +static struct callout mb_reclaim_callout; +static struct mtx mb_reclaim_callout_mtx; + +/* * Local prototypes. */ static int mb_ctor_mbuf(void *, int, void *, int); @@ -285,6 +294,7 @@ static void mb_zfini_pack(void *, int); static void mb_reclaim(void *); static void *mbuf_jumbo_alloc(uma_zone_t, vm_size_t, uint8_t *, int); +static void mb_maxaction(uma_zone_t); /* Ensure that MSIZE is a power of 2. */ CTASSERT((((MSIZE - 1) ^ MSIZE) + 1) >> 1 == MSIZE); @@ -310,6 +320,7 @@ mbuf_init(void *dummy) if (nmbufs > 0) nmbufs = uma_zone_set_max(zone_mbuf, nmbufs); uma_zone_set_warning(zone_mbuf, "kern.ipc.nmbufs limit reached"); + uma_zone_set_maxaction(zone_mbuf, mb_maxaction); zone_clust = uma_zcreate(MBUF_CLUSTER_MEM_NAME, MCLBYTES, mb_ctor_clust, mb_dtor_clust, @@ -322,6 +333,7 @@ mbuf_init(void *dummy) if (nmbclusters > 0) nmbclusters = uma_zone_set_max(zone_clust, nmbclusters); uma_zone_set_warning(zone_clust, "kern.ipc.nmbclusters limit reached"); + uma_zone_set_maxaction(zone_clust, mb_maxaction); zone_pack = uma_zsecond_create(MBUF_PACKET_MEM_NAME, mb_ctor_pack, mb_dtor_pack, mb_zinit_pack, mb_zfini_pack, zone_mbuf); @@ -338,6 +350,7 @@ mbuf_init(void *dummy) if (nmbjumbop > 0) nmbjumbop = uma_zone_set_max(zone_jumbop, nmbjumbop); uma_zone_set_warning(zone_jumbop, "kern.ipc.nmbjumbop limit reached"); + uma_zone_set_maxaction(zone_jumbop, mb_maxaction); zone_jumbo9 = uma_zcreate(MBUF_JUMBO9_MEM_NAME, MJUM9BYTES, mb_ctor_clust, mb_dtor_clust, @@ -351,6 +364,7 @@ mbuf_init(void *dummy) if (nmbjumbo9 > 0) nmbjumbo9 = uma_zone_set_max(zone_jumbo9, nmbjumbo9); uma_zone_set_warning(zone_jumbo9, "kern.ipc.nmbjumbo9 limit reached"); + uma_zone_set_maxaction(zone_jumbo9, mb_maxaction); zone_jumbo16 = uma_zcreate(MBUF_JUMBO16_MEM_NAME, MJUM16BYTES, mb_ctor_clust, mb_dtor_clust, @@ -364,6 +378,7 @@ mbuf_init(void *dummy) if (nmbjumbo16 > 0) nmbjumbo16 = uma_zone_set_max(zone_jumbo16, nmbjumbo16); uma_zone_set_warning(zone_jumbo16, "kern.ipc.nmbjumbo16 limit reached"); + uma_zone_set_maxaction(zone_jumbo16, mb_maxaction); zone_ext_refcnt = uma_zcreate(MBUF_EXTREFCNT_MEM_NAME, sizeof(u_int), NULL, NULL, @@ -372,6 +387,11 @@ mbuf_init(void *dummy) /* uma_prealloc() goes here... */ + /* Initialize the mb_reclaim() callout. */ + mtx_init(&mb_reclaim_callout_mtx, "mb_reclaim_callout_mtx", NULL, + MTX_DEF); + callout_init(&mb_reclaim_callout, 1); + /* * Hook event handler for low-memory situation, used to * drain protocols and push data back to the caches (UMA @@ -678,3 +698,61 @@ mb_reclaim(void *junk) if (pr->pr_drain != NULL) (*pr->pr_drain)(); } + +/* + * This is the function called by the mb_reclaim_callout, which is + * used when we hit the maximum for a zone. + * + * (See mb_maxaction() below.) + */ +static void +mb_reclaim_timer(void *junk __unused) +{ + + mtx_lock(&mb_reclaim_callout_mtx); + + /* + * Avoid running this function extra times by skipping this invocation + * if the callout has already been rescheduled. + */ + if (callout_pending(&mb_reclaim_callout) || + !callout_active(&mb_reclaim_callout)) { + mtx_unlock(&mb_reclaim_callout_mtx); + return; + } + mtx_unlock(&mb_reclaim_callout_mtx); + + mb_reclaim(NULL); + + mtx_lock(&mb_reclaim_callout_mtx); + callout_deactivate(&mb_reclaim_callout); + mtx_unlock(&mb_reclaim_callout_mtx); +} + +/* + * This function is called when we hit the maximum for a zone. + * + * At that point, we want to call the protocol drain routine to free up some + * mbufs. However, we will use the callout routines to schedule this to + * occur in another thread. (The thread calling this function holds the + * zone lock.) + */ +static void +mb_maxaction(uma_zone_t zone __unused) +{ + + /* + * If we can't immediately obtain the lock, either the callout + * is currently running, or another thread is scheduling the + * callout. + */ + if (!mtx_trylock(&mb_reclaim_callout_mtx)) + return; + + /* If not already scheduled/running, schedule the callout. */ + if (!callout_active(&mb_reclaim_callout)) { + callout_reset(&mb_reclaim_callout, 1, mb_reclaim_timer, NULL); + } + + mtx_unlock(&mb_reclaim_callout_mtx); +} |
