svn commit: r368162 - head/sys/sys

[Konstantin Belousov]

Author: kib
Date: Sun Nov 29 19:06:32 2020
New Revision: 368162
URL: https://svnweb.freebsd.org/changeset/base/368162

Log:
  Reduce MAXPHYS back to 128KB on 32bit architectures.
  
  Some of them have limited KVA, like arm, which prevents startup from
  allocating needed number of large pbufs.  Other, for instance i386,
  are dis-balanced enough after 4/4 that blind bump is probably harmful
  because it allows for much more in-flight io than other tunables are
  ready for.
  
  Requested by:	mmel
  Reviewed by:	emaste, mmel
  Sponsored by:	The FreeBSD Foundation

Modified:
  head/sys/sys/param.h

Modified: head/sys/sys/param.h
==============================================================================
--- head/sys/sys/param.h	Sun Nov 29 18:59:01 2020	(r368161)
+++ head/sys/sys/param.h	Sun Nov 29 19:06:32 2020	(r368162)
@@ -159,8 +159,12 @@
 #ifndef DFLTPHYS
 #define DFLTPHYS	(64 * 1024)	/* default max raw I/O transfer size */
 #endif
-#ifndef MAXPHYS
-#define MAXPHYS		(1024 * 1024)	/* max raw I/O transfer size */
+#ifndef MAXPHYS				/* max raw I/O transfer size */
+#ifdef __ILP32__
+#define MAXPHYS		(128 * 1024)
+#else
+#define MAXPHYS		(1024 * 1024)
+#endif
 #endif
 #ifndef MAXDUMPPGS
 #define MAXDUMPPGS	(DFLTPHYS/PAGE_SIZE)