Index: amd64/amd64/mp_machdep.c
===================================================================
--- amd64/amd64/mp_machdep.c
+++ amd64/amd64/mp_machdep.c
@@ -402,18 +402,14 @@
 		apic_id = cpu_apic_ids[cpu];
 
 		/* allocate and set up an idle stack data page */
-		bootstacks[cpu] = (void *)kmem_malloc(kernel_arena,
-		    kstack_pages * PAGE_SIZE, M_WAITOK | M_ZERO);
-		doublefault_stack = (char *)kmem_malloc(kernel_arena,
-		    PAGE_SIZE, M_WAITOK | M_ZERO);
-		mce_stack = (char *)kmem_malloc(kernel_arena, PAGE_SIZE,
+		bootstacks[cpu] = (void *)kmem_malloc(kstack_pages * PAGE_SIZE,
 		    M_WAITOK | M_ZERO);
-		nmi_stack = (char *)kmem_malloc(kernel_arena, PAGE_SIZE,
-		    M_WAITOK | M_ZERO);
-		dbg_stack = (char *)kmem_malloc(kernel_arena, PAGE_SIZE,
-		    M_WAITOK | M_ZERO);
-		dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
-		    M_WAITOK | M_ZERO);
+		doublefault_stack = (char *)kmem_malloc(PAGE_SIZE, M_WAITOK |
+		    M_ZERO);
+		mce_stack = (char *)kmem_malloc(PAGE_SIZE, M_WAITOK | M_ZERO);
+		nmi_stack = (char *)kmem_malloc(PAGE_SIZE, M_WAITOK | M_ZERO);
+		dbg_stack = (char *)kmem_malloc(PAGE_SIZE, M_WAITOK | M_ZERO);
+		dpcpu = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO);
 
 		bootSTK = (char *)bootstacks[cpu] + kstack_pages * PAGE_SIZE - 8;
 		bootAP = cpu;
Index: amd64/amd64/pmap.c
===================================================================
--- amd64/amd64/pmap.c
+++ amd64/amd64/pmap.c
@@ -1412,8 +1412,7 @@
 	 */
 	s = (vm_size_t)(pv_npg * sizeof(struct md_page));
 	s = round_page(s);
-	pv_table = (struct md_page *)kmem_malloc(kernel_arena, s,
-	    M_WAITOK | M_ZERO);
+	pv_table = (struct md_page *)kmem_malloc(s, M_WAITOK | M_ZERO);
 	for (i = 0; i < pv_npg; i++)
 		TAILQ_INIT(&pv_table[i].pv_list);
 	TAILQ_INIT(&pv_dummy.pv_list);
Index: amd64/amd64/sys_machdep.c
===================================================================
--- amd64/amd64/sys_machdep.c
+++ amd64/amd64/sys_machdep.c
@@ -361,8 +361,8 @@
 	 */
 	pcb = td->td_pcb;
 	if (pcb->pcb_tssp == NULL) {
-		tssp = (struct amd64tss *)kmem_malloc(kernel_arena,
-		    ctob(IOPAGES + 1), M_WAITOK);
+		tssp = (struct amd64tss *)kmem_malloc(ctob(IOPAGES + 1),
+		    M_WAITOK);
 		pmap_pti_add_kva((vm_offset_t)tssp, (vm_offset_t)tssp +
 		    ctob(IOPAGES + 1), false);
 		iomap = (char *)&tssp[1];
@@ -463,7 +463,7 @@
 	mtx_unlock(&dt_lock);
 	new_ldt = malloc(sizeof(struct proc_ldt), M_SUBPROC, M_WAITOK);
 	sz = max_ldt_segment * sizeof(struct user_segment_descriptor);
-	sva = kmem_malloc(kernel_arena, sz, M_WAITOK | M_ZERO);
+	sva = kmem_malloc(sz, M_WAITOK | M_ZERO);
 	new_ldt->ldt_base = (caddr_t)sva;
 	pmap_pti_add_kva(sva, sva + sz, false);
 	new_ldt->ldt_refcnt = 1;
Index: arm/arm/mp_machdep.c
===================================================================
--- arm/arm/mp_machdep.c
+++ arm/arm/mp_machdep.c
@@ -119,8 +119,7 @@
 
 	/* Reserve memory for application processors */
 	for(i = 0; i < (mp_ncpus - 1); i++)
-		dpcpu[i] = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
-		    M_WAITOK | M_ZERO);
+		dpcpu[i] = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO);
 
 	dcache_wbinv_poc_all();
 
Index: arm/arm/pmap-v6.c
===================================================================
--- arm/arm/pmap-v6.c
+++ arm/arm/pmap-v6.c
@@ -1782,8 +1782,7 @@
 	 */
 	s = (vm_size_t)(pv_npg * sizeof(struct md_page));
 	s = round_page(s);
-	pv_table = (struct md_page *)kmem_malloc(kernel_arena, s,
-	    M_WAITOK | M_ZERO);
+	pv_table = (struct md_page *)kmem_malloc(s, M_WAITOK | M_ZERO);
 	for (i = 0; i < pv_npg; i++)
 		TAILQ_INIT(&pv_table[i].pv_list);
 
Index: arm64/arm64/mp_machdep.c
===================================================================
--- arm64/arm64/mp_machdep.c
+++ arm64/arm64/mp_machdep.c
@@ -484,8 +484,7 @@
 	pcpup = &__pcpu[cpuid];
 	pcpu_init(pcpup, cpuid, sizeof(struct pcpu));
 
-	dpcpu[cpuid - 1] = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
-	    M_WAITOK | M_ZERO);
+	dpcpu[cpuid - 1] = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO);
 	dpcpu_init(dpcpu[cpuid - 1], cpuid);
 
 	printf("Starting CPU %u (%lx)\n", cpuid, target_cpu);
Index: arm64/arm64/pmap.c
===================================================================
--- arm64/arm64/pmap.c
+++ arm64/arm64/pmap.c
@@ -923,8 +923,7 @@
 	 */
 	s = (vm_size_t)(pv_npg * sizeof(struct md_page));
 	s = round_page(s);
-	pv_table = (struct md_page *)kmem_malloc(kernel_arena, s,
-	    M_WAITOK | M_ZERO);
+	pv_table = (struct md_page *)kmem_malloc(s, M_WAITOK | M_ZERO);
 	for (i = 0; i < pv_npg; i++)
 		TAILQ_INIT(&pv_table[i].pv_list);
 	TAILQ_INIT(&pv_dummy.pv_list);
Index: compat/linuxkpi/common/src/linux_page.c
===================================================================
--- compat/linuxkpi/common/src/linux_page.c
+++ compat/linuxkpi/common/src/linux_page.c
@@ -165,7 +165,7 @@
 	vm_offset_t addr;
 
 	if ((flags & GFP_DMA32) == 0) {
-		addr = kmem_malloc(kmem_arena, size, flags & GFP_NATIVE_MASK);
+		addr = kmem_malloc(size, flags & GFP_NATIVE_MASK);
 	} else {
 		addr = kmem_alloc_contig(size, flags & GFP_NATIVE_MASK, 0,
 		    BUS_SPACE_MAXADDR_32BIT, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
Index: dev/hyperv/vmbus/hyperv.c
===================================================================
--- dev/hyperv/vmbus/hyperv.c
+++ dev/hyperv/vmbus/hyperv.c
@@ -283,8 +283,8 @@
 	 *   the NX bit.
 	 * - Assume kmem_malloc() returns properly aligned memory.
 	 */
-	hypercall_context.hc_addr = (void *)kmem_malloc(kernel_arena, PAGE_SIZE,
-	    M_EXEC | M_WAITOK);
+	hypercall_context.hc_addr = (void *)kmem_malloc(PAGE_SIZE, M_EXEC |
+	    M_WAITOK);
 	hypercall_context.hc_paddr = vtophys(hypercall_context.hc_addr);
 
 	/* Get the 'reserved' bits, which requires preservation. */
Index: i386/i386/mp_machdep.c
===================================================================
--- i386/i386/mp_machdep.c
+++ i386/i386/mp_machdep.c
@@ -328,11 +328,9 @@
 		apic_id = cpu_apic_ids[cpu];
 
 		/* allocate and set up a boot stack data page */
-		bootstacks[cpu] =
-		    (char *)kmem_malloc(kernel_arena, kstack_pages * PAGE_SIZE,
+		bootstacks[cpu] = (char *)kmem_malloc(kstack_pages * PAGE_SIZE,
 		    M_WAITOK | M_ZERO);
-		dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
-		    M_WAITOK | M_ZERO);
+		dpcpu = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO);
 		/* setup a vector to our boot code */
 		*((volatile u_short *) WARMBOOT_OFF) = WARMBOOT_TARGET;
 		*((volatile u_short *) WARMBOOT_SEG) = (boot_address >> 4);
Index: i386/i386/pmap.c
===================================================================
--- i386/i386/pmap.c
+++ i386/i386/pmap.c
@@ -998,8 +998,7 @@
 	 */
 	s = (vm_size_t)(pv_npg * sizeof(struct md_page));
 	s = round_page(s);
-	pv_table = (struct md_page *)kmem_malloc(kernel_arena, s,
-	    M_WAITOK | M_ZERO);
+	pv_table = (struct md_page *)kmem_malloc(s, M_WAITOK | M_ZERO);
 	for (i = 0; i < pv_npg; i++)
 		TAILQ_INIT(&pv_table[i].pv_list);
 
Index: mips/mips/mp_machdep.c
===================================================================
--- mips/mips/mp_machdep.c
+++ mips/mips/mp_machdep.c
@@ -185,7 +185,7 @@
 	int cpus, ms;
 
 	cpus = mp_naps;
-	dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE, M_WAITOK | M_ZERO);
+	dpcpu = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO);
 
 	mips_sync();
 
Index: powerpc/powerpc/mp_machdep.c
===================================================================
--- powerpc/powerpc/mp_machdep.c
+++ powerpc/powerpc/mp_machdep.c
@@ -168,8 +168,8 @@
 			void *dpcpu;
 
 			pc = &__pcpu[cpu.cr_cpuid];
-			dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
-			    M_WAITOK | M_ZERO);
+			dpcpu = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK |
+			    M_ZERO);
 			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
 			dpcpu_init(dpcpu, cpu.cr_cpuid);
 		} else {
Index: riscv/riscv/mp_machdep.c
===================================================================
--- riscv/riscv/mp_machdep.c
+++ riscv/riscv/mp_machdep.c
@@ -391,8 +391,7 @@
 
 	pcpu_init(pcpup, id, sizeof(struct pcpu));
 
-	dpcpu[id - 1] = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
-	    M_WAITOK | M_ZERO);
+	dpcpu[id - 1] = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO);
 	dpcpu_init(dpcpu[id - 1], id);
 
 	printf("Starting CPU %u (%lx)\n", id, target_cpu);
Index: sparc64/sparc64/mp_machdep.c
===================================================================
--- sparc64/sparc64/mp_machdep.c
+++ sparc64/sparc64/mp_machdep.c
@@ -342,12 +342,10 @@
 	cpuid_to_mid[cpuid] = mid;
 	cpu_identify(csa->csa_ver, clock, cpuid);
 
-	va = kmem_malloc(kernel_arena, PCPU_PAGES * PAGE_SIZE,
-	    M_WAITOK | M_ZERO);
+	va = kmem_malloc(PCPU_PAGES * PAGE_SIZE, M_WAITOK | M_ZERO);
 	pc = (struct pcpu *)(va + (PCPU_PAGES * PAGE_SIZE)) - 1;
 	pcpu_init(pc, cpuid, sizeof(*pc));
-	dpcpu_init((void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
-	    M_WAITOK | M_ZERO), cpuid);
+	dpcpu_init((void *)kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO), cpuid);
 	pc->pc_addr = va;
 	pc->pc_clock = clock;
 	pc->pc_impl = cpu_impl;
Index: vm/uma_core.c
===================================================================
--- vm/uma_core.c
+++ vm/uma_core.c
@@ -3687,7 +3687,7 @@
 	if (slab == NULL)
 		return (NULL);
 	if (domain == UMA_ANYDOMAIN)
-		addr = kmem_malloc(NULL, size, wait);
+		addr = kmem_malloc(size, wait);
 	else
 		addr = kmem_malloc_domain(domain, size, wait);
 	if (addr != 0) {
Index: vm/vm_extern.h
===================================================================
--- vm/vm_extern.h
+++ vm/vm_extern.h
@@ -64,7 +64,7 @@
 vm_offset_t kmem_alloc_contig_domain(int domain, vm_size_t size, int flags,
     vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary,
     vm_memattr_t memattr);
-vm_offset_t kmem_malloc(struct vmem *, vm_size_t size, int flags);
+vm_offset_t kmem_malloc(vm_size_t size, int flags);
 vm_offset_t kmem_malloc_domain(int domain, vm_size_t size, int flags);
 void kmem_free(struct vmem *, vm_offset_t, vm_size_t);
 
Index: vm/vm_init.c
===================================================================
--- vm/vm_init.c
+++ vm/vm_init.c
@@ -278,8 +278,7 @@
 		    (vm_paddr_t)1 << 32, ~(vm_paddr_t)0, VM_MEMATTR_DEFAULT);
 		if (firstaddr == 0)
 #endif
-			firstaddr = kmem_malloc(kernel_arena, size,
-			    M_ZERO | M_WAITOK);
+			firstaddr = kmem_malloc(size, M_ZERO | M_WAITOK);
 		if (firstaddr == 0)
 			panic("startup: no room for tables");
 		goto again;
Index: vm/vm_kern.c
===================================================================
--- vm/vm_kern.c
+++ vm/vm_kern.c
@@ -392,7 +392,7 @@
 }
 
 vm_offset_t
-kmem_malloc(struct vmem *vmem __unused, vm_size_t size, int flags)
+kmem_malloc(vm_size_t size, int flags)
 {
 	struct vm_domainset_iter di;
 	vm_offset_t addr;
Index: x86/xen/pv.c
===================================================================
--- x86/xen/pv.c
+++ x86/xen/pv.c
@@ -350,18 +350,12 @@
 	const size_t stacksize = kstack_pages * PAGE_SIZE;
 
 	/* allocate and set up an idle stack data page */
-	bootstacks[cpu] =
-	    (void *)kmem_malloc(kernel_arena, stacksize, M_WAITOK | M_ZERO);
-	doublefault_stack =
-	    (char *)kmem_malloc(kernel_arena, PAGE_SIZE, M_WAITOK | M_ZERO);
-	mce_stack =
-	    (char *)kmem_malloc(kernel_arena, PAGE_SIZE, M_WAITOK | M_ZERO);
-	nmi_stack =
-	    (char *)kmem_malloc(kernel_arena, PAGE_SIZE, M_WAITOK | M_ZERO);
-	dbg_stack =
-	    (void *)kmem_malloc(kernel_arena, PAGE_SIZE, M_WAITOK | M_ZERO);
-	dpcpu =
-	    (void *)kmem_malloc(kernel_arena, DPCPU_SIZE, M_WAITOK | M_ZERO);
+	bootstacks[cpu] = (void *)kmem_malloc(stacksize, M_WAITOK | M_ZERO);
+	doublefault_stack = (char *)kmem_malloc(PAGE_SIZE, M_WAITOK | M_ZERO);
+	mce_stack = (char *)kmem_malloc(PAGE_SIZE, M_WAITOK | M_ZERO);
+	nmi_stack = (char *)kmem_malloc(PAGE_SIZE, M_WAITOK | M_ZERO);
+	dbg_stack = (void *)kmem_malloc(PAGE_SIZE, M_WAITOK | M_ZERO);
+	dpcpu = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO);
 
 	bootSTK = (char *)bootstacks[cpu] + kstack_pages * PAGE_SIZE - 8;
 	bootAP = cpu;