Optimize arc_l2c_only lists assertions

It is very expensive and not informative to call multilist_is_empty()
for each arc_change_state() on debug builds to check for impossible.
Instead implement special index function for arc_l2c_only->arcs_list,
multilists, panicking on any attempt to use it.

Reviewed-by: Mark Maybee <mark.maybee@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored-By: iXsystems, Inc.
Closes #12421
This commit is contained in:
Alexander Motin 2021-08-17 11:55:34 -04:00 committed by GitHub
parent cfe8e960f1
commit bb7ad5d326
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1 changed files with 12 additions and 9 deletions

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@ -2578,13 +2578,6 @@ arc_change_state(arc_state_t *new_state, arc_buf_hdr_t *hdr,
l2arc_hdr_arcstats_increment_state(hdr);
}
}
/*
* L2 headers should never be on the L2 state list since they don't
* have L1 headers allocated.
*/
ASSERT(multilist_is_empty(&arc_l2c_only->arcs_list[ARC_BUFC_DATA]) &&
multilist_is_empty(&arc_l2c_only->arcs_list[ARC_BUFC_METADATA]));
}
void
@ -7456,6 +7449,12 @@ arc_state_multilist_index_func(multilist_t *ml, void *obj)
multilist_get_num_sublists(ml));
}
static unsigned int
arc_state_l2c_multilist_index_func(multilist_t *ml, void *obj)
{
panic("Header %p insert into arc_l2c_only %p", obj, ml);
}
#define WARN_IF_TUNING_IGNORED(tuning, value, do_warn) do { \
if ((do_warn) && (tuning) && ((tuning) != (value))) { \
cmn_err(CE_WARN, \
@ -7603,14 +7602,18 @@ arc_state_init(void)
sizeof (arc_buf_hdr_t),
offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node),
arc_state_multilist_index_func);
/*
* L2 headers should never be on the L2 state list since they don't
* have L1 headers allocated. Special index function asserts that.
*/
multilist_create(&arc_l2c_only->arcs_list[ARC_BUFC_METADATA],
sizeof (arc_buf_hdr_t),
offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node),
arc_state_multilist_index_func);
arc_state_l2c_multilist_index_func);
multilist_create(&arc_l2c_only->arcs_list[ARC_BUFC_DATA],
sizeof (arc_buf_hdr_t),
offsetof(arc_buf_hdr_t, b_l1hdr.b_arc_node),
arc_state_multilist_index_func);
arc_state_l2c_multilist_index_func);
zfs_refcount_create(&arc_anon->arcs_esize[ARC_BUFC_METADATA]);
zfs_refcount_create(&arc_anon->arcs_esize[ARC_BUFC_DATA]);