Don't ignore zfs_arc_max below allmem/32

Set arc_c_min before arc_c_max so that when zfs_arc_min is set lower
than the default allmem/32 zfs_arc_max can also be set lower.

Add warning messages when tunables are being ignored.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #10157
Closes #10158
This commit is contained in:
Ryan Moeller 2020-04-09 18:39:48 -04:00 committed by GitHub
parent 8b27e08ed8
commit 36a6e2335c
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 31 additions and 15 deletions

View File

@ -612,7 +612,7 @@ extern void arc_prune_async(int64_t);
extern int arc_memory_throttle(spa_t *spa, uint64_t reserve, uint64_t txg);
extern uint64_t arc_free_memory(void);
extern int64_t arc_available_memory(void);
extern void arc_tuning_update(void);
extern void arc_tuning_update(boolean_t);
extern int param_set_arc_long(ZFS_MODULE_PARAM_ARGS);
extern int param_set_arc_int(ZFS_MODULE_PARAM_ARGS);

View File

@ -377,7 +377,7 @@ param_set_arc_long(const char *buf, zfs_kernel_param_t *kp)
if (error < 0)
return (SET_ERROR(error));
arc_tuning_update();
arc_tuning_update(B_TRUE);
return (0);
}
@ -391,7 +391,7 @@ param_set_arc_int(const char *buf, zfs_kernel_param_t *kp)
if (error < 0)
return (SET_ERROR(error));
arc_tuning_update();
arc_tuning_update(B_TRUE);
return (0);
}

View File

@ -4558,7 +4558,7 @@ arc_adjust_cb_check(void *arg, zthr_t *zthr)
* their actual internal variable counterparts. Without this,
* changing those module params at runtime would have no effect.
*/
arc_tuning_update();
arc_tuning_update(B_FALSE);
/*
* This is necessary in order to keep the kstat information
@ -6900,6 +6900,14 @@ arc_state_multilist_index_func(multilist_t *ml, void *obj)
multilist_get_num_sublists(ml));
}
#define WARN_IF_TUNING_IGNORED(tuning, value, do_warn) do { \
if ((do_warn) && (tuning) && ((tuning) != (value))) { \
cmn_err(CE_WARN, \
"ignoring tunable %s (using %llu instead)", \
(#tuning), (value)); \
} \
} while (0)
/*
* Called during module initialization and periodically thereafter to
* apply reasonable changes to the exposed performance tunings. Can also be
@ -6908,11 +6916,20 @@ arc_state_multilist_index_func(multilist_t *ml, void *obj)
* values will be applied.
*/
void
arc_tuning_update(void)
arc_tuning_update(boolean_t verbose)
{
uint64_t allmem = arc_all_memory();
unsigned long limit;
/* Valid range: 32M - <arc_c_max> */
if ((zfs_arc_min) && (zfs_arc_min != arc_c_min) &&
(zfs_arc_min >= 2ULL << SPA_MAXBLOCKSHIFT) &&
(zfs_arc_min <= arc_c_max)) {
arc_c_min = zfs_arc_min;
arc_c = MAX(arc_c, arc_c_min);
}
WARN_IF_TUNING_IGNORED(zfs_arc_min, arc_c_min, verbose);
/* Valid range: 64M - <all physical memory> */
if ((zfs_arc_max) && (zfs_arc_max != arc_c_max) &&
(zfs_arc_max >= 64 << 20) && (zfs_arc_max < allmem) &&
@ -6925,14 +6942,7 @@ arc_tuning_update(void)
if (arc_dnode_size_limit > arc_meta_limit)
arc_dnode_size_limit = arc_meta_limit;
}
/* Valid range: 32M - <arc_c_max> */
if ((zfs_arc_min) && (zfs_arc_min != arc_c_min) &&
(zfs_arc_min >= 2ULL << SPA_MAXBLOCKSHIFT) &&
(zfs_arc_min <= arc_c_max)) {
arc_c_min = zfs_arc_min;
arc_c = MAX(arc_c, arc_c_min);
}
WARN_IF_TUNING_IGNORED(zfs_arc_max, arc_c_max, verbose);
/* Valid range: 16M - <arc_c_max> */
if ((zfs_arc_meta_min) && (zfs_arc_meta_min != arc_meta_min) &&
@ -6944,6 +6954,7 @@ arc_tuning_update(void)
if (arc_dnode_size_limit < arc_meta_min)
arc_dnode_size_limit = arc_meta_min;
}
WARN_IF_TUNING_IGNORED(zfs_arc_meta_min, arc_meta_min, verbose);
/* Valid range: <arc_meta_min> - <arc_c_max> */
limit = zfs_arc_meta_limit ? zfs_arc_meta_limit :
@ -6952,6 +6963,7 @@ arc_tuning_update(void)
(limit >= arc_meta_min) &&
(limit <= arc_c_max))
arc_meta_limit = limit;
WARN_IF_TUNING_IGNORED(zfs_arc_meta_limit, arc_meta_limit, verbose);
/* Valid range: <arc_meta_min> - <arc_meta_limit> */
limit = zfs_arc_dnode_limit ? zfs_arc_dnode_limit :
@ -6960,6 +6972,8 @@ arc_tuning_update(void)
(limit >= arc_meta_min) &&
(limit <= arc_meta_limit))
arc_dnode_size_limit = limit;
WARN_IF_TUNING_IGNORED(zfs_arc_dnode_limit, arc_dnode_size_limit,
verbose);
/* Valid range: 1 - N */
if (zfs_arc_grow_retry)
@ -6989,11 +7003,13 @@ arc_tuning_update(void)
if ((zfs_arc_lotsfree_percent >= 0) &&
(zfs_arc_lotsfree_percent <= 100))
arc_lotsfree_percent = zfs_arc_lotsfree_percent;
WARN_IF_TUNING_IGNORED(zfs_arc_lotsfree_percent, arc_lotsfree_percent,
verbose);
/* Valid range: 0 - <all physical memory> */
if ((zfs_arc_sys_free) && (zfs_arc_sys_free != arc_sys_free))
arc_sys_free = MIN(MAX(zfs_arc_sys_free, 0), allmem);
WARN_IF_TUNING_IGNORED(zfs_arc_sys_free, arc_sys_free, verbose);
}
static void
@ -7183,7 +7199,7 @@ arc_init(void)
arc_dnode_size_limit = (percent * arc_meta_limit) / 100;
/* Apply user specified tunings */
arc_tuning_update();
arc_tuning_update(B_TRUE);
/* if kmem_flags are set, lets try to use less memory */
if (kmem_debugging())