svn commit: r354159 - head/sys/cddl/contrib/opensolaris/uts/common/zmod

[Alexander Motin]

Author: mav
Date: Tue Oct 29 21:25:19 2019
New Revision: 354159
URL: https://svnweb.freebsd.org/changeset/base/354159

Log:
  FreeBSD'fy ZFS zlib zalloc/zfree callbacks.
  
  The previous code came from OpenSolaris, which in my understanding require
  allocation size to be known to free memory.  To store that size previous
  code allocated additional 8 byte header.  But I have noticed that zlib
  with present settings allocates 64KB context buffers for each call, that
  could be efficiently cached by UMA, but addition of those 8 bytes makes
  them fall back to physical RAM allocations, that cause huge overhead and
  lock congestion on small blocks.  Since FreeBSD's free() does not have
  the size argument, switching to it solves the problem, increasing write
  speed to ZVOLs with 4KB block size and GZIP compression on my 40-threads
  test system from ~60MB/s to ~600MB/s.
  
  MFC after:	1 week
  Sponsored by:	iXsystems, Inc.

Modified:
  head/sys/cddl/contrib/opensolaris/uts/common/zmod/zmod.c

Modified: head/sys/cddl/contrib/opensolaris/uts/common/zmod/zmod.c
==============================================================================
--- head/sys/cddl/contrib/opensolaris/uts/common/zmod/zmod.c	Tue Oct 29 21:06:34 2019	(r354158)
+++ head/sys/cddl/contrib/opensolaris/uts/common/zmod/zmod.c	Tue Oct 29 21:25:19 2019	(r354159)
@@ -27,45 +27,28 @@
 #include <sys/types.h>
 #include <sys/cmn_err.h>
 #include <sys/systm.h>
-#include <sys/kobj.h>
+#include <sys/kmem.h>
 #include <sys/zmod.h>
 
 #include <contrib/zlib/zlib.h>
 #include <contrib/zlib/zutil.h>
 
-struct zchdr {
-	uint_t zch_magic;
-	uint_t zch_size;
-};
-
-#define	ZCH_MAGIC	0x3cc13cc1
-
 /*ARGSUSED*/
 static void *
 zfs_zcalloc(void *opaque, uint_t items, uint_t size)
 {
-	size_t nbytes = sizeof (struct zchdr) + items * size;
-	struct zchdr *z = kobj_zalloc(nbytes, KM_NOWAIT|KM_TMP);
+	void *ptr;
 
-	if (z == NULL)
-		return (NULL);
-
-	z->zch_magic = ZCH_MAGIC;
-	z->zch_size = nbytes;
-
-	return (z + 1);
+	ptr = malloc((size_t)items * size, M_SOLARIS, M_NOWAIT);
+	return ptr;
 }
 
 /*ARGSUSED*/
 static void
 zfs_zcfree(void *opaque, void *ptr)
 {
-	struct zchdr *z = ((struct zchdr *)ptr) - 1;
 
-	if (z->zch_magic != ZCH_MAGIC)
-		panic("zcfree region corrupt: hdr=%p ptr=%p", (void *)z, ptr);
-
-	kobj_free(z, z->zch_size);
+	free(ptr, M_SOLARIS);
 }
 
 /*