svn commit: r328611 - head/sys/dev/ntb

[Alexander Motin]

Author: mav
Date: Wed Jan 31 01:04:36 2018
New Revision: 328611
URL: https://svnweb.freebsd.org/changeset/base/328611

Log:
  Try to preallocate receive memory early.
  
  We may not have enough contiguous memory later, when NTB connection get
  established.  It is quite likely that NTB windows are symmetric and this
  allocation remain, but even if not, we will just reallocate it later.
  
  MFC after:	2 weeks

Modified:
  head/sys/dev/ntb/ntb_transport.c

Modified: head/sys/dev/ntb/ntb_transport.c
==============================================================================
--- head/sys/dev/ntb/ntb_transport.c	Tue Jan 30 23:29:27 2018	(r328610)
+++ head/sys/dev/ntb/ntb_transport.c	Wed Jan 31 01:04:36 2018	(r328611)
@@ -332,7 +332,7 @@ ntb_transport_attach(device_t dev)
 	struct ntb_transport_child **cpp = &nt->child;
 	struct ntb_transport_child *nc;
 	struct ntb_transport_mw *mw;
-	uint64_t db_bitmap;
+	uint64_t db_bitmap, size;
 	int rc, i, db_count, spad_count, qp, qpu, qpo, qpt;
 	char cfg[128] = "";
 	char buf[32];
@@ -383,6 +383,17 @@ ntb_transport_attach(device_t dev)
 		rc = ntb_mw_set_wc(dev, i, VM_MEMATTR_WRITE_COMBINING);
 		if (rc)
 			ntb_printf(0, "Unable to set mw%d caching\n", i);
+
+		/*
+		 * Try to preallocate receive memory early, since there may
+		 * be not enough contiguous memory later.  It is quite likely
+		 * that NTB windows are symmetric and this allocation remain,
+		 * but even if not, we will just reallocate it later.
+		 */
+		size = mw->phys_size;
+		if (max_mw_size != 0 && size > max_mw_size)
+			size = max_mw_size;
+		ntb_set_mw(nt, i, size);
 	}
 
 	qpu = 0;