diff options
Diffstat (limited to 'usr/src/uts/common/fs/zfs/dmu.c')
| -rw-r--r-- | usr/src/uts/common/fs/zfs/dmu.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/usr/src/uts/common/fs/zfs/dmu.c b/usr/src/uts/common/fs/zfs/dmu.c index da84226c14..e299096351 100644 --- a/usr/src/uts/common/fs/zfs/dmu.c +++ b/usr/src/uts/common/fs/zfs/dmu.c @@ -88,6 +88,13 @@ uint32_t zfs_per_txg_dirty_frees_percent = 30; */ int zfs_object_remap_one_indirect_delay_ticks = 0; +/* + * Limit the amount we can prefetch with one call to this amount. This + * helps to limit the amount of memory that can be used by prefetching. + * Larger objects should be prefetched a bit at a time. + */ +uint64_t dmu_prefetch_max = 8 * SPA_MAXBLOCKSIZE; + const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES] = { { DMU_BSWAP_UINT8, TRUE, FALSE, "unallocated" }, { DMU_BSWAP_ZAP, TRUE, TRUE, "object directory" }, @@ -638,6 +645,11 @@ dmu_prefetch(objset_t *os, uint64_t object, int64_t level, uint64_t offset, } /* + * See comment before the definition of dmu_prefetch_max. + */ + len = MIN(len, dmu_prefetch_max); + + /* * XXX - Note, if the dnode for the requested object is not * already cached, we will do a *synchronous* read in the * dnode_hold() call. The same is true for any indirects. |