svn commit: r337824 - head/sys/cam

[Warner Losh]

Author: imp
Date: Wed Aug 15 00:15:40 2018
New Revision: 337824
URL: https://svnweb.freebsd.org/changeset/base/337824

Log:
  Flesh out a comment about what we're doing with read bias and trims.
  
  Sponsored by: Netflix

Modified:
  head/sys/cam/cam_iosched.c

Modified: head/sys/cam/cam_iosched.c
==============================================================================
--- head/sys/cam/cam_iosched.c	Tue Aug 14 22:57:28 2018	(r337823)
+++ head/sys/cam/cam_iosched.c	Wed Aug 15 00:15:40 2018	(r337824)
@@ -1311,7 +1311,9 @@ cam_iosched_get_trim(struct cam_iosched_softc *isc)
 	if (do_dynamic_iosched) {
 		/*
 		 * If pending read, prefer that based on current read bias
-		 * setting.
+		 * setting. The read bias is shared for both writes and
+		 * TRIMs, but on TRIMs the bias is for a combined TRIM
+		 * not a single TRIM request that's come in.
 		 */
 		if (bioq_first(&isc->bio_queue) && isc->current_read_bias) {
 			isc->current_read_bias--;