Remove KMC_NOHASH

Remove dead code to make the implementation easier to understand.

Reviewed-by: Ryan Moeller <ryan@ixsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Ahrens <matt@delphix.com>
Closes #10650

include/os/linux/spl/sys/kmem_cache.h

@@ -38,7 +38,6 @@
 typedef enum kmc_bit {
 	KMC_BIT_NODEBUG		= 1,	/* Default behavior */
 	KMC_BIT_NOMAGAZINE	= 2,	/* XXX: Unsupported */
-	KMC_BIT_NOHASH		= 3,	/* XXX: Unsupported */
 	KMC_BIT_QCACHE		= 4,	/* XXX: Unsupported */
 	KMC_BIT_KMEM		= 5,	/* Use kmem cache */
 	KMC_BIT_VMEM		= 6,	/* Use vmem cache */
@@ -64,7 +63,6 @@ typedef enum kmem_cbrc {
 
 #define	KMC_NODEBUG		(1 << KMC_BIT_NODEBUG)
 #define	KMC_NOMAGAZINE		(1 << KMC_BIT_NOMAGAZINE)
-#define	KMC_NOHASH		(1 << KMC_BIT_NOHASH)
 #define	KMC_QCACHE		(1 << KMC_BIT_QCACHE)
 #define	KMC_KMEM		(1 << KMC_BIT_KMEM)
 #define	KMC_VMEM		(1 << KMC_BIT_VMEM)

lib/libspl/include/umem.h

@@ -57,10 +57,8 @@ typedef void vmem_t;
 /*
  * Flags for umem_cache_create()
  */
-#define	UMC_NOTOUCH		0x00010000
 #define	UMC_NODEBUG		0x00020000
 #define	UMC_NOMAGAZINE		0x00040000
-#define	UMC_NOHASH		0x00080000
 
 #define	UMEM_CACHE_NAMELEN	31
 

module/os/linux/spl/spl-kmem-cache.c

@@ -721,7 +721,6 @@ spl_magazine_destroy(spl_kmem_cache_t *skc)
  *	KMC_KVMEM       Force kvmem backed SPL cache
  *	KMC_SLAB        Force Linux slab backed cache
  *	KMC_NODEBUG	Disable debugging (unsupported)
- *	KMC_NOHASH      Disable hashing (unsupported)
  *	KMC_QCACHE	Disable qcache (unsupported)
  *	KMC_NOMAGAZINE	Enabled for kmem/vmem, Disabled for Linux slab
  */
@@ -738,7 +737,6 @@ spl_kmem_cache_create(char *name, size_t size, size_t align,
 	 * Unsupported flags
 	 */
 	ASSERT0(flags & KMC_NOMAGAZINE);
-	ASSERT0(flags & KMC_NOHASH);
 	ASSERT0(flags & KMC_QCACHE);
 	ASSERT(vmp == NULL);
 	ASSERT(reclaim == NULL);