b7654bd794
The l2arc_evict() function is responsible for evicting buffers which reference the next bytes of the L2ARC device to be overwritten. Teach this function to additionally TRIM that vdev space before it is overwritten if the device has been filled with data. This is done by vdev_trim_simple() which trims by issuing a new type of TRIM, TRIM_TYPE_SIMPLE. We also implement a "Trim Ahead" feature. It is a zfs module parameter, expressed in % of the current write size. This trims ahead of the current write size. A minimum of 64MB will be trimmed. The default is 0 which disables TRIM on L2ARC as it can put significant stress to underlying storage devices. To enable TRIM on L2ARC we set l2arc_trim_ahead > 0. We also implement TRIM of the whole cache device upon addition to a pool, pool creation or when the header of the device is invalid upon importing a pool or onlining a cache device. This is dependent on l2arc_trim_ahead > 0. TRIM of the whole device is done with TRIM_TYPE_MANUAL so that its status can be monitored by zpool status -t. We save the TRIM state for the whole device and the time of completion on-disk in the header, and restore these upon L2ARC rebuild so that zpool status -t can correctly report them. Whole device TRIM is done asynchronously so that the user can export of the pool or remove the cache device while it is trimming (ie if it is too slow). We do not TRIM the whole device if persistent L2ARC has been disabled by l2arc_rebuild_enabled = 0 because we may not want to lose all cached buffers (eg we may want to import the pool with l2arc_rebuild_enabled = 0 only once because of memory pressure). If persistent L2ARC has been disabled by setting the module parameter l2arc_rebuild_blocks_min_l2size to a value greater than the size of the cache device then the whole device is trimmed upon creation or import of a pool if l2arc_trim_ahead > 0. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Adam D. Moss <c@yotes.com> Signed-off-by: George Amanakis <gamanakis@gmail.com> Closes #9713 Closes #9789 Closes #10224
55 lines
1.7 KiB
C
55 lines
1.7 KiB
C
/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License (the "License").
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* You may not use this file except in compliance with the License.
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*
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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* or http://www.opensolaris.org/os/licensing.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*/
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/*
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* Copyright (c) 2019 Lawrence Livermore National Security, LLC.
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*/
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#ifndef _SYS_VDEV_TRIM_H
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#define _SYS_VDEV_TRIM_H
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#include <sys/spa.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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extern unsigned int zfs_trim_metaslab_skip;
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extern void vdev_trim(vdev_t *vd, uint64_t rate, boolean_t partial,
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boolean_t secure);
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extern void vdev_trim_stop(vdev_t *vd, vdev_trim_state_t tgt, list_t *vd_list);
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extern void vdev_trim_stop_all(vdev_t *vd, vdev_trim_state_t tgt_state);
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extern void vdev_trim_stop_wait(spa_t *spa, list_t *vd_list);
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extern void vdev_trim_restart(vdev_t *vd);
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extern void vdev_autotrim(spa_t *spa);
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extern void vdev_autotrim_stop_all(spa_t *spa);
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extern void vdev_autotrim_stop_wait(vdev_t *vd);
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extern void vdev_autotrim_restart(spa_t *spa);
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extern int vdev_trim_simple(vdev_t *vd, uint64_t start, uint64_t size);
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extern void vdev_trim_l2arc(spa_t *spa);
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#ifdef __cplusplus
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}
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#endif
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#endif /* _SYS_VDEV_TRIM_H */
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