Change l2arc_norw default to zero

These days modern SSDs can efficiently service concurrent reads
and writes.  When this flag was added that wasn't really the
case for a variety of SSD controllers.  But now we can set the
default value to take advantage of this parallelism and only
disable this as needed for specific troublesome hardware.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>

diff --git a/module/zfs/arc.c b/module/zfs/arc.c
index 3fd4fa0..dca17ab 100644 (file)
--- a/module/zfs/arc.c
+++ b/module/zfs/arc.c
@@ -640,7 +640,7 @@ 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 */
+int l2arc_norw = B_FALSE;                      /* no reads during writes */
 
 /*
  * L2ARC Internals