Trim L2ARC

cmd/zdb/zdb.c

@@ -3707,8 +3707,12 @@ dump_l2arc_header(int fd)
 		    (u_longlong_t)l2dhdr.dh_evict);
 		(void) printf("    lb_asize_refcount: %llu\n",
 		    (u_longlong_t)l2dhdr.dh_lb_asize);
-		(void) printf("    lb_count_refcount: %llu\n\n",
+		(void) printf("    lb_count_refcount: %llu\n",
 		    (u_longlong_t)l2dhdr.dh_lb_count);
+		(void) printf("    trim_action_time: %llu\n",
+		    (u_longlong_t)l2dhdr.dh_trim_action_time);
+		(void) printf("    trim_state: %llu\n\n",
+		    (u_longlong_t)l2dhdr.dh_trim_state);
 	}
 
 	dump_l2arc_log_blocks(fd, l2dhdr, &rebuild);

include/sys/arc_impl.h

@@ -240,7 +240,14 @@ typedef struct l2arc_dev_hdr_phys {
 	 */
 	uint64_t	dh_lb_asize;		/* mirror of l2ad_lb_asize */
 	uint64_t	dh_lb_count;		/* mirror of l2ad_lb_count */
-	const uint64_t		dh_pad[32];	/* pad to 512 bytes */
+	/*
+	 * Mirrors of vdev_trim_action_time and vdev_trim_state, used to
+	 * display when the cache device was fully trimmed for the last
+	 * time.
+	 */
+	uint64_t		dh_trim_action_time;
+	uint64_t		dh_trim_state;
+	const uint64_t		dh_pad[30];	/* pad to 512 bytes */
 	zio_eck_t		dh_tail;
 } l2arc_dev_hdr_phys_t;
 CTASSERT_GLOBAL(sizeof (l2arc_dev_hdr_phys_t) == SPA_MINBLOCKSIZE);
@@ -399,6 +406,7 @@ typedef struct l2arc_dev {
 	 * Number of log blocks present on the device.
 	 */
 	zfs_refcount_t		l2ad_lb_count;
+	boolean_t		l2ad_trim_all; /* TRIM whole device */
 } l2arc_dev_t;
 
 /*
@@ -902,6 +910,10 @@ extern int param_set_arc_int(ZFS_MODULE_PARAM_ARGS);
 boolean_t l2arc_log_blkptr_valid(l2arc_dev_t *dev,
     const l2arc_log_blkptr_t *lbp);
 
+/* used in vdev_trim.c */
+void l2arc_dev_hdr_update(l2arc_dev_t *dev);
+l2arc_dev_t *l2arc_vdev_get(vdev_t *vd);
+
 #ifdef __cplusplus
 }
 #endif

include/sys/spa.h

@@ -745,6 +745,7 @@ typedef enum {
 typedef enum trim_type {
 	TRIM_TYPE_MANUAL = 0,
 	TRIM_TYPE_AUTO = 1,
+	TRIM_TYPE_SIMPLE = 2
 } trim_type_t;
 
 /* state manipulation functions */
@@ -788,6 +789,7 @@ extern int bpobj_enqueue_free_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx);
 #define	SPA_ASYNC_TRIM_RESTART			0x200
 #define	SPA_ASYNC_AUTOTRIM_RESTART		0x400
 #define	SPA_ASYNC_L2CACHE_REBUILD		0x800
+#define	SPA_ASYNC_L2CACHE_TRIM			0x1000
 
 /*
  * Controls the behavior of spa_vdev_remove().
@@ -940,6 +942,12 @@ typedef struct spa_iostats {
 	kstat_named_t	autotrim_bytes_skipped;
 	kstat_named_t	autotrim_extents_failed;
 	kstat_named_t	autotrim_bytes_failed;
+	kstat_named_t	simple_trim_extents_written;
+	kstat_named_t	simple_trim_bytes_written;
+	kstat_named_t	simple_trim_extents_skipped;
+	kstat_named_t	simple_trim_bytes_skipped;
+	kstat_named_t	simple_trim_extents_failed;
+	kstat_named_t	simple_trim_bytes_failed;
 } spa_iostats_t;
 
 extern void spa_stats_init(spa_t *spa);

include/sys/vdev_impl.h

@@ -301,7 +301,7 @@ struct vdev {
 	uint64_t	vdev_initialize_inflight;
 	kmutex_t	vdev_trim_io_lock;
 	kcondvar_t	vdev_trim_io_cv;
-	uint64_t	vdev_trim_inflight[2];
+	uint64_t	vdev_trim_inflight[3];
 
 	/*
 	 * Values stored in the config for an indirect or removing vdev.

include/sys/vdev_trim.h

@@ -44,6 +44,8 @@ extern void vdev_autotrim(spa_t *spa);
 extern void vdev_autotrim_stop_all(spa_t *spa);
 extern void vdev_autotrim_stop_wait(vdev_t *vd);
 extern void vdev_autotrim_restart(spa_t *spa);
+extern int vdev_trim_simple(vdev_t *vd, uint64_t start, uint64_t size);
+extern void vdev_trim_l2arc(spa_t *spa);
 
 #ifdef	__cplusplus
 }

man/man5/zfs-module-parameters.5

@@ -194,11 +194,31 @@ Default value: \fB2\fR.
 .ad
 .RS 12n
 Scales \fBl2arc_headroom\fR by this percentage when L2ARC contents are being
-successfully compressed before writing. A value of 100 disables this feature.
+successfully compressed before writing. A value of \fB100\fR disables this
+feature.
 .sp
 Default value: \fB200\fR%.
 .RE
 
+.sp
+.ne 2
+.na
+\fBl2arc_trim_ahead\fR (ulong)
+.ad
+.RS 12n
+Trims ahead of the current write size (\fBl2arc_write_max\fR) on L2ARC devices
+by this percentage of write size if we have filled the device. If set to
+\fB100\fR we TRIM twice the space required to accommodate upcoming writes. A
+minimum of 64MB will be trimmed. It also enables TRIM of the whole L2ARC device
+upon creation or addition to an existing pool or if the header of the device is
+invalid upon importing a pool or onlining a cache device. A value of \fB0\fR
+disables TRIM on L2ARC altogether and is the default as it can put significant
+stress on the underlying storage devices. This will vary depending of how well
+the specific device handles these commands.
+.sp
+Default value: \fB0\fR%.
+.RE
+
 .sp
 .ne 2
 .na

man/man8/zpoolprops.8

@@ -238,6 +238,8 @@ this property is
 Automatic TRIM does not immediately reclaim blocks after a free. Instead,
 it will optimistically delay allowing smaller ranges to be aggregated in to
 a few larger ones.  These can then be issued more efficiently to the storage.
+TRIM on L2ARC devices is enabled by setting
+.Sy l2arc_trim_ahead > 0 .
 .Pp
 Be aware that automatic trimming of recently freed data blocks can put
 significant stress on the underlying storage devices.  This will vary

module/os/linux/zfs/spa_stats.c

@@ -903,6 +903,12 @@ static spa_iostats_t spa_iostats_template = {
 	{ "autotrim_bytes_skipped",		KSTAT_DATA_UINT64 },
 	{ "autotrim_extents_failed",		KSTAT_DATA_UINT64 },
 	{ "autotrim_bytes_failed",		KSTAT_DATA_UINT64 },
+	{ "simple_trim_extents_written",	KSTAT_DATA_UINT64 },
+	{ "simple_trim_bytes_written",		KSTAT_DATA_UINT64 },
+	{ "simple_trim_extents_skipped",	KSTAT_DATA_UINT64 },
+	{ "simple_trim_bytes_skipped",		KSTAT_DATA_UINT64 },
+	{ "simple_trim_extents_failed",		KSTAT_DATA_UINT64 },
+	{ "simple_trim_bytes_failed",		KSTAT_DATA_UINT64 },
 };
 
 #define	SPA_IOSTATS_ADD(stat, val) \
@@ -929,13 +935,20 @@ spa_iostats_trim_add(spa_t *spa, trim_type_t type,
 		SPA_IOSTATS_ADD(trim_bytes_skipped, bytes_skipped);
 		SPA_IOSTATS_ADD(trim_extents_failed, extents_failed);
 		SPA_IOSTATS_ADD(trim_bytes_failed, bytes_failed);
-	} else {
+	} else if (type == TRIM_TYPE_AUTO) {
 		SPA_IOSTATS_ADD(autotrim_extents_written, extents_written);
 		SPA_IOSTATS_ADD(autotrim_bytes_written, bytes_written);
 		SPA_IOSTATS_ADD(autotrim_extents_skipped, extents_skipped);
 		SPA_IOSTATS_ADD(autotrim_bytes_skipped, bytes_skipped);
 		SPA_IOSTATS_ADD(autotrim_extents_failed, extents_failed);
 		SPA_IOSTATS_ADD(autotrim_bytes_failed, bytes_failed);
+	} else {
+		SPA_IOSTATS_ADD(simple_trim_extents_written, extents_written);
+		SPA_IOSTATS_ADD(simple_trim_bytes_written, bytes_written);
+		SPA_IOSTATS_ADD(simple_trim_extents_skipped, extents_skipped);
+		SPA_IOSTATS_ADD(simple_trim_bytes_skipped, bytes_skipped);
+		SPA_IOSTATS_ADD(simple_trim_extents_failed, extents_failed);
+		SPA_IOSTATS_ADD(simple_trim_bytes_failed, bytes_failed);
 	}
 }