Re: [PATCH] printk: ringbuffer: fix error in comment

[John Ogness]

On 2026-03-27, Loïc Grégoire <loicgre@xxxxxxxxx> wrote:
> The printk ringbuffer implementation is described in the comment as
> using three ringbuffers, but the current implementation uses two (desc
> and data). Update the comment so it matches the code.
>
> Signed-off-by: Loïc Grégoire <loicgre@xxxxxxxxx>

Reviewed-by: John Ogness <john.ogness@xxxxxxxxxxxxx>

However, this is only a single fixup when there are other documentation
errors that need fixing as well. Does it make sense to commit such tiny
fixups separately? For example, below are needed fixes that I am aware
of.

Perhaps we should fold these into a single doc-fixup patch?

John

diff --git a/kernel/printk/printk_ringbuffer.c b/kernel/printk/printk_ringbuffer.c
index 56c8e3d031f49..3f019207d2688 100644
--- a/kernel/printk/printk_ringbuffer.c
+++ b/kernel/printk/printk_ringbuffer.c
@@ -224,7 +224,7 @@
  *
  *	prb_rec_init_rd(&r, &info, &text_buf[0], sizeof(text_buf));
  *
- *	prb_for_each_record(0, &test_rb, &seq, &r) {
+ *	prb_for_each_record(0, &test_rb, seq, &r) {
  *		if (info.seq != seq)
  *			pr_warn("lost %llu records\n", info.seq - seq);
  *
@@ -1365,7 +1365,7 @@ static struct prb_desc *desc_reopen_last(struct prb_desc_ring *desc_ring,
 	 *
 	 * WMB from _prb_commit:A to _prb_commit:B
 	 *    matching
-	 * MB If desc_reopen_last:A to prb_reserve_in_last:A
+	 * MB from desc_reopen_last:A to prb_reserve_in_last:A
 	 */
 	if (!atomic_long_try_cmpxchg(&d->state_var, &prev_state_val,
 			DESC_SV(id, desc_reserved))) { /* LMM(desc_reopen_last:A) */
@@ -1770,9 +1770,9 @@ static void _prb_commit(struct prb_reserved_entry *e, unsigned long state_val)
 	 *
 	 *    Relies on:
 	 *
-	 *    MB _prb_commit:B to prb_commit:A
+	 *    MB from _prb_commit:B to prb_commit:A
 	 *       matching
-	 *    MB desc_reserve:D to desc_make_final:A
+	 *    MB from desc_reserve:D to desc_make_final:A
 	 */
 	if (!atomic_long_try_cmpxchg(&d->state_var, &prev_state_val,
 			DESC_SV(e->id, state_val))) { /* LMM(_prb_commit:B) */
@@ -2035,7 +2035,7 @@ u64 prb_first_seq(struct printk_ringbuffer *rb)
 		 *
 		 * MB from desc_push_tail:B to desc_reserve:F
 		 *    matching
-		 * RMB prb_first_seq:B to prb_first_seq:A
+		 * RMB from prb_first_seq:B to prb_first_seq:A
 		 */
 		smp_rmb(); /* LMM(prb_first_seq:C) */
 	}
diff --git a/kernel/printk/printk_ringbuffer.h b/kernel/printk/printk_ringbuffer.h
index 1651b53ece34f..fb7d2ee29af23 100644
--- a/kernel/printk/printk_ringbuffer.h
+++ b/kernel/printk/printk_ringbuffer.h
@@ -388,7 +388,7 @@ for ((s) = from; prb_read_valid(rb, s, r); (s) = (r)->info->seq + 1)
  *
  * This is a macro for conveniently iterating over a ringbuffer.
  * Note that @s may not be the sequence number of the record on each
- * iteration. For the sequence number, @r->info->seq should be checked.
+ * iteration. For the sequence number, @i->seq should be checked.
  *
  * Context: Any context.
  */