Attachment 242680 Details for Bug 271772 – openzfs/zfs commit bcd5321 adapated for application to FreeBSD src

[patch] openzfs/zfs commit bcd5321 adapated for application to FreeBSD src

bcd5321039c3de29c14eac1068d392c15ad7fe2c-271772.patch (text/plain), 4.42 KB, created by Graham Perrin on 2023-06-08 06:32:18 UTC

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Creator: Graham Perrin

Created: 2023-06-08 06:32:18 UTC

Size: 4.42 KB

patch

obsolete

>From bcd5321039c3de29c14eac1068d392c15ad7fe2c Mon Sep 17 00:00:00 2001
>From: George Amanakis <gamanakis@gmail.com>
>Date: Tue, 6 Jun 2023 21:32:37 +0200
>Subject: [PATCH] Fix the L2ARC write size calculating logic
>
>l2arc_write_size() should return the write size after adjusting for trim
>and overhead of the L2ARC log blocks. Also take into account the
>allocated size of log blocks when deciding when to stop writing buffers
>to L2ARC.
>
>https://bugs.freebsd.org/271772
>
>PR:                      271772
>Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
>Signed-off-by: George Amanakis <gamanakis@gmail.com>
>Closes https://github.com/openzfs/zfs/pull/14939
>---
> module/zfs/arc.c | 45 +++++++++++++++++++++++++++++----------------
> 1 file changed, 29 insertions(+), 16 deletions(-)
>
>diff --git a/sys/contrib/openzfs/module/zfs/arc.c b/sys/contrib/openzfs/module/zfs/arc.c
>index a78f664c4fe..6f68c29fc7f 100644
>--- a/sys/contrib/openzfs/module/zfs/arc.c
>+++ b/sys/contrib/openzfs/module/zfs/arc.c
>@@ -965,7 +965,7 @@ static void l2arc_hdr_restore(const l2arc_log_ent_phys_t *le,
>     l2arc_dev_t *dev);
> 
> /* L2ARC persistence write I/O routines. */
>-static void l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio,
>+static uint64_t l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio,
>     l2arc_write_callback_t *cb);
> 
> /* L2ARC persistence auxiliary routines. */
>@@ -8175,7 +8175,7 @@ l2arc_write_eligible(uint64_t spa_guid, arc_buf_hdr_t *hdr)
> static uint64_t
> l2arc_write_size(l2arc_dev_t *dev)
> {
>-	uint64_t size, dev_size, tsize;
>+	uint64_t size;
> 
> 	/*
> 	 * Make sure our globals have meaningful values in case the user
>@@ -8192,35 +8192,40 @@ l2arc_write_size(l2arc_dev_t *dev)
> 	if (arc_warm == B_FALSE)
> 		size += l2arc_write_boost;
> 
>-	/*
>-	 * Make sure the write size does not exceed the size of the cache
>-	 * device. This is important in l2arc_evict(), otherwise infinite
>-	 * iteration can occur.
>-	 */
>-	dev_size = dev->l2ad_end - dev->l2ad_start;
>-
> 	/* We need to add in the worst case scenario of log block overhead. */
>-	tsize = size + l2arc_log_blk_overhead(size, dev);
>+	size += l2arc_log_blk_overhead(size, dev);
> 	if (dev->l2ad_vdev->vdev_has_trim && l2arc_trim_ahead > 0) {
> 		/*
> 		 * Trim ahead of the write size 64MB or (l2arc_trim_ahead/100)
> 		 * times the writesize, whichever is greater.
> 		 */
>-		tsize += MAX(64 * 1024 * 1024,
>-		    (tsize * l2arc_trim_ahead) / 100);
>+		size += MAX(64 * 1024 * 1024,
>+		    (size * l2arc_trim_ahead) / 100);
> 	}
> 
>-	if (tsize >= dev_size) {
>+	/*
>+	 * Make sure the write size does not exceed the size of the cache
>+	 * device. This is important in l2arc_evict(), otherwise infinite
>+	 * iteration can occur.
>+	 */
>+	if (size >= dev->l2ad_end - dev->l2ad_start) {
> 		cmn_err(CE_NOTE, "l2arc_write_max or l2arc_write_boost "
> 		    "plus the overhead of log blocks (persistent L2ARC, "
> 		    "%llu bytes) exceeds the size of the cache device "
> 		    "(guid %llu), resetting them to the default (%d)",
> 		    (u_longlong_t)l2arc_log_blk_overhead(size, dev),
> 		    (u_longlong_t)dev->l2ad_vdev->vdev_guid, L2ARC_WRITE_SIZE);
>+
> 		size = l2arc_write_max = l2arc_write_boost = L2ARC_WRITE_SIZE;
> 
> 		if (arc_warm == B_FALSE)
> 			size += l2arc_write_boost;
>+
>+		size += l2arc_log_blk_overhead(size, dev);
>+		if (dev->l2ad_vdev->vdev_has_trim && l2arc_trim_ahead > 0) {
>+			size += MAX(64 * 1024 * 1024,
>+			    (size * l2arc_trim_ahead) / 100);
>+		}
> 	}
> 
> 	return (size);
>@@ -9413,8 +9418,14 @@ l2arc_write_buffers(spa_t *spa, l2arc_dev_t *dev, uint64_t target_sz)
> 			 * arcstat_l2_{size,asize} kstats are updated
> 			 * internally.
> 			 */
>-			if (l2arc_log_blk_insert(dev, hdr))
>-				l2arc_log_blk_commit(dev, pio, cb);
>+			if (l2arc_log_blk_insert(dev, hdr)) {
>+				/*
>+				 * l2ad_hand has been accounted for in
>+				 * l2arc_log_blk_commit().
>+				 */
>+				write_asize +=
>+				    l2arc_log_blk_commit(dev, pio, cb);
>+			}
> 
> 			zio_nowait(wzio);
> 		}
>@@ -10564,7 +10575,7 @@ l2arc_dev_hdr_update(l2arc_dev_t *dev)
>  * This function allocates some memory to temporarily hold the serialized
>  * buffer to be written. This is then released in l2arc_write_done.
>  */
>-static void
>+static uint64_t
> l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio, l2arc_write_callback_t *cb)
> {
> 	l2arc_log_blk_phys_t	*lb = &dev->l2ad_log_blk;
>@@ -10675,6 +10686,8 @@ l2arc_log_blk_commit(l2arc_dev_t *dev, zio_t *pio, l2arc_write_callback_t *cb)
> 	dev->l2ad_log_ent_idx = 0;
> 	dev->l2ad_log_blk_payload_asize = 0;
> 	dev->l2ad_log_blk_payload_start = 0;
>+
>+	return (asize);
> }
> 
> /*

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Attachments on bug 271772: 242680 | 242818