svn commit: r356480 - head/sys/dev/nvme

[Alexander Motin]

Author: mav
Date: Tue Jan  7 23:10:38 2020
New Revision: 356480
URL: https://svnweb.freebsd.org/changeset/base/356480

Log:
  Increate HMB limit from 1% to 5%.
  
  SSD capacity in laptops is growing faster then RAM size, so my original
  guess seems too low on second thought.  Hopefully nobody will build large
  array of those crappy SSDs.
  
  MFC after:	2 weeks
  X-MFC-with:	356474

Modified:
  head/sys/dev/nvme/nvme_ctrlr.c

Modified: head/sys/dev/nvme/nvme_ctrlr.c
==============================================================================
--- head/sys/dev/nvme/nvme_ctrlr.c	Tue Jan  7 22:45:02 2020	(r356479)
+++ head/sys/dev/nvme/nvme_ctrlr.c	Tue Jan  7 23:10:38 2020	(r356480)
@@ -881,8 +881,8 @@ nvme_ctrlr_hmb_alloc(struct nvme_controller *ctrlr)
 	int err, i;
 	uint64_t max;
 
-	/* Limit HMB to 1% of RAM size per device by default. */
-	max = (uint64_t)physmem * PAGE_SIZE / 100;
+	/* Limit HMB to 5% of RAM size per device by default. */
+	max = (uint64_t)physmem * PAGE_SIZE / 20;
 	TUNABLE_UINT64_FETCH("hw.nvme.hmb_max", &max);
 
 	min = (long long unsigned)ctrlr->cdata.hmmin * 4096;