Add L2ARC tunables

The performance of the L2ARC can be tweaked by a number of tunables, which
may be necessary for different workloads:

     l2arc_write_max         max write bytes per interval
     l2arc_write_boost       extra write bytes during device warmup
     l2arc_noprefetch        skip caching prefetched buffers
     l2arc_headroom          number of max device writes to precache
     l2arc_feed_secs         seconds between L2ARC writing
     l2arc_feed_min_ms       min feed interval in milliseconds
     l2arc_feed_again        turbo L2ARC warmup
     l2arc_norw              no reads during writes

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #316
This commit is contained in:
Brian Behlendorf 2011-07-08 12:41:57 -07:00
parent e0f86c9862
commit abd8610cd5

View File

@ -582,14 +582,14 @@ uint64_t zfs_crc64_table[256];
/*
* L2ARC Performance Tunables
*/
uint64_t l2arc_write_max = L2ARC_WRITE_SIZE; /* default max write size */
uint64_t l2arc_write_boost = L2ARC_WRITE_SIZE; /* extra write during warmup */
uint64_t l2arc_headroom = L2ARC_HEADROOM; /* number of dev writes */
uint64_t l2arc_feed_secs = L2ARC_FEED_SECS; /* interval seconds */
uint64_t l2arc_feed_min_ms = L2ARC_FEED_MIN_MS; /* min interval milliseconds */
boolean_t l2arc_noprefetch = B_TRUE; /* don't cache prefetch bufs */
boolean_t l2arc_feed_again = B_TRUE; /* turbo warmup */
boolean_t l2arc_norw = B_TRUE; /* no reads during writes */
unsigned long l2arc_write_max = L2ARC_WRITE_SIZE; /* def max write size */
unsigned long l2arc_write_boost = L2ARC_WRITE_SIZE; /* extra warmup write */
unsigned long l2arc_headroom = L2ARC_HEADROOM; /* # of dev writes */
unsigned long l2arc_feed_secs = L2ARC_FEED_SECS; /* interval seconds */
unsigned long l2arc_feed_min_ms = L2ARC_FEED_MIN_MS; /* min interval msecs */
int l2arc_noprefetch = B_TRUE; /* don't cache prefetch bufs */
int l2arc_feed_again = B_TRUE; /* turbo warmup */
int l2arc_norw = B_TRUE; /* no reads during writes */
/*
* L2ARC Internals
@ -4796,4 +4796,28 @@ MODULE_PARM_DESC(zfs_arc_shrink_shift, "log2(fraction of arc to reclaim)");
module_param(zfs_arc_p_min_shift, int, 0444);
MODULE_PARM_DESC(zfs_arc_p_min_shift, "arc_c shift to calc min/max arc_p");
module_param(l2arc_write_max, ulong, 0444);
MODULE_PARM_DESC(l2arc_write_max, "Max write bytes per interval");
module_param(l2arc_write_boost, ulong, 0444);
MODULE_PARM_DESC(l2arc_write_boost, "Extra write bytes during device warmup");
module_param(l2arc_headroom, ulong, 0444);
MODULE_PARM_DESC(l2arc_headroom, "Number of max device writes to precache");
module_param(l2arc_feed_secs, ulong, 0444);
MODULE_PARM_DESC(l2arc_feed_secs, "Seconds between L2ARC writing");
module_param(l2arc_feed_min_ms, ulong, 0444);
MODULE_PARM_DESC(l2arc_feed_min_ms, "Min feed interval in milliseconds");
module_param(l2arc_noprefetch, int, 0444);
MODULE_PARM_DESC(l2arc_noprefetch, "Skip caching prefetched buffers");
module_param(l2arc_feed_again, int, 0444);
MODULE_PARM_DESC(l2arc_feed_again, "Turbo L2ARC warmup");
module_param(l2arc_norw, int, 0444);
MODULE_PARM_DESC(l2arc_norw, "No reads during writes");
#endif