git: 7a79d0669761 - main - vm: improve kstack_object pindex calculation to avoid pindex holes
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Date: Wed, 10 Apr 2024 15:37:37 UTC
The branch main has been updated by bnovkov:
URL: https://cgit.FreeBSD.org/src/commit/?id=7a79d066976149349ecb90240d02eed0c4268737
commit 7a79d066976149349ecb90240d02eed0c4268737
Author: Bojan Novković <bnovkov@FreeBSD.org>
AuthorDate: 2024-04-09 19:02:12 +0000
Commit: Bojan Novković <bnovkov@FreeBSD.org>
CommitDate: 2024-04-10 15:37:20 +0000
vm: improve kstack_object pindex calculation to avoid pindex holes
This commit replaces the linear transformation of kernel virtual
addresses to kstack_object pindex values with a non-linear
scheme that circumvents physical memory fragmentation caused by
kernel stack guard pages. The new mapping scheme is used to
effectively "skip" guard pages and assign pindices for
non-guard pages in a contiguous fashion.
The new allocation scheme requires that all default-sized kstack KVAs
come from a separate, specially aligned region of the KVA space.
For this to work, this commited introduces a dedicated per-domain
kstack KVA arena used to allocate kernel stacks of default size.
The behaviour on 32-bit platforms remains unchanged due to a
significatly smaller KVA space.
Aside from fullfilling the requirements imposed by the new scheme, a
separate kstack KVA arena facilitates superpage promotion in the rest
of kernel and causes most kstacks to have guard pages at both ends.
Reviewed by: alc, kib, markj
Tested by: markj
Approved by: markj (mentor)
Differential Revision: https://reviews.freebsd.org/D38852
---
sys/sys/proc.h | 3 +-
sys/vm/vm_extern.h | 6 +-
sys/vm/vm_glue.c | 336 +++++++++++++++++++++++++++++++++++++++++++++-------
sys/vm/vm_kern.h | 2 -
sys/vm/vm_swapout.c | 29 +++--
5 files changed, 314 insertions(+), 62 deletions(-)
diff --git a/sys/sys/proc.h b/sys/sys/proc.h
index b08226c89dfd..fa4c7d2768f0 100644
--- a/sys/sys/proc.h
+++ b/sys/sys/proc.h
@@ -366,7 +366,8 @@ struct thread {
struct callout td_slpcallout; /* (h) Callout for sleep. */
struct trapframe *td_frame; /* (k) */
vm_offset_t td_kstack; /* (a) Kernel VA of kstack. */
- int td_kstack_pages; /* (a) Size of the kstack. */
+ u_short td_kstack_pages; /* (a) Size of the kstack. */
+ u_short td_kstack_domain; /* (a) Domain backing kstack KVA. */
volatile u_int td_critnest; /* (k*) Critical section nest level. */
struct mdthread td_md; /* (k) Any machine-dependent fields. */
struct kaudit_record *td_ar; /* (k) Active audit record, if any. */
diff --git a/sys/vm/vm_extern.h b/sys/vm/vm_extern.h
index 2e2bc18a0233..b50abab7380c 100644
--- a/sys/vm/vm_extern.h
+++ b/sys/vm/vm_extern.h
@@ -127,8 +127,10 @@ struct sf_buf *vm_imgact_map_page(vm_object_t object, vm_ooffset_t offset);
void vm_imgact_unmap_page(struct sf_buf *sf);
void vm_thread_dispose(struct thread *td);
int vm_thread_new(struct thread *td, int pages);
-void vm_thread_stack_back(struct domainset *ds, vm_offset_t kaddr,
- vm_page_t ma[], int npages, int req_class);
+vm_pindex_t vm_kstack_pindex(vm_offset_t ks, int npages);
+vm_object_t vm_thread_kstack_size_to_obj(int npages);
+int vm_thread_stack_back(vm_offset_t kaddr, vm_page_t ma[], int npages,
+ int req_class, int domain);
u_int vm_active_count(void);
u_int vm_inactive_count(void);
u_int vm_laundry_count(void);
diff --git a/sys/vm/vm_glue.c b/sys/vm/vm_glue.c
index 100d31e7c4ec..4292a7533503 100644
--- a/sys/vm/vm_glue.c
+++ b/sys/vm/vm_glue.c
@@ -96,14 +96,23 @@
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
+#include <vm/vm_pagequeue.h>
#include <vm/vm_object.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
#include <vm/vm_pager.h>
#include <vm/swap_pager.h>
+#include <vm/vm_phys.h>
#include <machine/cpu.h>
+#if VM_NRESERVLEVEL > 0
+#define KVA_KSTACK_QUANTUM_SHIFT (VM_LEVEL_0_ORDER + PAGE_SHIFT)
+#else
+#define KVA_KSTACK_QUANTUM_SHIFT (8 + PAGE_SHIFT)
+#endif
+#define KVA_KSTACK_QUANTUM (1ul << KVA_KSTACK_QUANTUM_SHIFT)
+
/*
* MPSAFE
*
@@ -262,9 +271,11 @@ vm_sync_icache(vm_map_t map, vm_offset_t va, vm_offset_t sz)
pmap_sync_icache(map->pmap, va, sz);
}
-vm_object_t kstack_object;
+static vm_object_t kstack_object;
+static vm_object_t kstack_alt_object;
static uma_zone_t kstack_cache;
static int kstack_cache_size;
+static vmem_t *vmd_kstack_arena[MAXMEMDOM];
static int
sysctl_kstack_cache_size(SYSCTL_HANDLER_ARGS)
@@ -282,63 +293,218 @@ SYSCTL_PROC(_vm, OID_AUTO, kstack_cache_size,
sysctl_kstack_cache_size, "IU", "Maximum number of cached kernel stacks");
/*
- * Create the kernel stack (including pcb for i386) for a new thread.
+ * Allocate a virtual address range from a domain kstack arena, following
+ * the specified NUMA policy.
*/
static vm_offset_t
-vm_thread_stack_create(struct domainset *ds, int pages)
+vm_thread_alloc_kstack_kva(vm_size_t size, int domain)
{
- vm_page_t ma[KSTACK_MAX_PAGES];
- vm_offset_t ks;
- int i;
+#ifndef __ILP32__
+ int rv;
+ vmem_t *arena;
+ vm_offset_t addr = 0;
+
+ size = round_page(size);
+ /* Allocate from the kernel arena for non-standard kstack sizes. */
+ if (size != ptoa(kstack_pages + KSTACK_GUARD_PAGES)) {
+ arena = vm_dom[domain].vmd_kernel_arena;
+ } else {
+ arena = vmd_kstack_arena[domain];
+ }
+ rv = vmem_alloc(arena, size, M_BESTFIT | M_NOWAIT, &addr);
+ if (rv == ENOMEM)
+ return (0);
+ KASSERT(atop(addr - VM_MIN_KERNEL_ADDRESS) %
+ (kstack_pages + KSTACK_GUARD_PAGES) == 0,
+ ("%s: allocated kstack KVA not aligned to multiple of kstack size",
+ __func__));
+
+ return (addr);
+#else
+ return (kva_alloc(size));
+#endif
+}
+/*
+ * Release a region of kernel virtual memory
+ * allocated from the kstack arena.
+ */
+static __noinline void
+vm_thread_free_kstack_kva(vm_offset_t addr, vm_size_t size, int domain)
+{
+ vmem_t *arena;
+
+ size = round_page(size);
+#ifdef __ILP32__
+ arena = kernel_arena;
+#else
+ arena = vmd_kstack_arena[domain];
+ if (size != ptoa(kstack_pages + KSTACK_GUARD_PAGES)) {
+ arena = vm_dom[domain].vmd_kernel_arena;
+ }
+#endif
+ vmem_free(arena, addr, size);
+}
+
+static vmem_size_t
+vm_thread_kstack_import_quantum(void)
+{
+#ifndef __ILP32__
/*
- * Get a kernel virtual address for this thread's kstack.
+ * The kstack_quantum is larger than KVA_QUANTUM to account
+ * for holes induced by guard pages.
*/
- ks = kva_alloc((pages + KSTACK_GUARD_PAGES) * PAGE_SIZE);
- if (ks == 0) {
- printf("%s: kstack allocation failed\n", __func__);
- return (0);
+ return (KVA_KSTACK_QUANTUM * (kstack_pages + KSTACK_GUARD_PAGES));
+#else
+ return (KVA_KSTACK_QUANTUM);
+#endif
+}
+
+/*
+ * Import KVA from a parent arena into the kstack arena. Imports must be
+ * a multiple of kernel stack pages + guard pages in size.
+ *
+ * Kstack VA allocations need to be aligned so that the linear KVA pindex
+ * is divisible by the total number of kstack VA pages. This is necessary to
+ * make vm_kstack_pindex work properly.
+ *
+ * We import a multiple of KVA_KSTACK_QUANTUM-sized region from the parent
+ * arena. The actual size used by the kstack arena is one kstack smaller to
+ * allow for the necessary alignment adjustments to be made.
+ */
+static int
+vm_thread_kstack_arena_import(void *arena, vmem_size_t size, int flags,
+ vmem_addr_t *addrp)
+{
+ int error, rem;
+ size_t kpages = kstack_pages + KSTACK_GUARD_PAGES;
+
+ KASSERT(atop(size) % kpages == 0,
+ ("%s: Size %jd is not a multiple of kstack pages (%d)", __func__,
+ (intmax_t)size, (int)kpages));
+
+ error = vmem_xalloc(arena, vm_thread_kstack_import_quantum(),
+ KVA_KSTACK_QUANTUM, 0, 0, VMEM_ADDR_MIN, VMEM_ADDR_MAX, flags,
+ addrp);
+ if (error) {
+ return (error);
}
- if (KSTACK_GUARD_PAGES != 0) {
- pmap_qremove(ks, KSTACK_GUARD_PAGES);
- ks += KSTACK_GUARD_PAGES * PAGE_SIZE;
+ rem = atop(*addrp - VM_MIN_KERNEL_ADDRESS) % kpages;
+ if (rem != 0) {
+ /* Bump addr to next aligned address */
+ *addrp = *addrp + (kpages - rem) * PAGE_SIZE;
}
+ return (0);
+}
+
+/*
+ * Release KVA from a parent arena into the kstack arena. Released imports must
+ * be a multiple of kernel stack pages + guard pages in size.
+ */
+static void
+vm_thread_kstack_arena_release(void *arena, vmem_addr_t addr, vmem_size_t size)
+{
+ int rem;
+ size_t kpages __diagused = kstack_pages + KSTACK_GUARD_PAGES;
+
+ KASSERT(size % kpages == 0,
+ ("%s: Size %jd is not a multiple of kstack pages (%d)", __func__,
+ (intmax_t)size, (int)kpages));
+
+ KASSERT((addr - VM_MIN_KERNEL_ADDRESS) % kpages == 0,
+ ("%s: Address %p is not properly aligned (%p)", __func__,
+ (void *)addr, (void *)VM_MIN_KERNEL_ADDRESS));
/*
- * Allocate physical pages to back the stack.
+ * If the address is not KVA_KSTACK_QUANTUM-aligned we have to decrement
+ * it to account for the shift in kva_import_kstack.
*/
- vm_thread_stack_back(ds, ks, ma, pages, VM_ALLOC_NORMAL);
- for (i = 0; i < pages; i++)
- vm_page_valid(ma[i]);
- pmap_qenter(ks, ma, pages);
+ rem = addr % KVA_KSTACK_QUANTUM;
+ if (rem) {
+ KASSERT(rem <= ptoa(kpages),
+ ("%s: rem > kpages (%d), (%d)", __func__, rem,
+ (int)kpages));
+ addr -= rem;
+ }
+ vmem_xfree(arena, addr, vm_thread_kstack_import_quantum());
+}
+
+/*
+ * Create the kernel stack for a new thread.
+ */
+static vm_offset_t
+vm_thread_stack_create(struct domainset *ds, int pages)
+{
+ vm_page_t ma[KSTACK_MAX_PAGES];
+ struct vm_domainset_iter di;
+ int req = VM_ALLOC_NORMAL;
+ vm_object_t obj;
+ vm_offset_t ks;
+ int domain, i;
+
+ obj = vm_thread_kstack_size_to_obj(pages);
+ if (vm_ndomains > 1)
+ obj->domain.dr_policy = ds;
+ vm_domainset_iter_page_init(&di, obj, 0, &domain, &req);
+ do {
+ /*
+ * Get a kernel virtual address for this thread's kstack.
+ */
+ ks = vm_thread_alloc_kstack_kva(ptoa(pages + KSTACK_GUARD_PAGES),
+ domain);
+ if (ks == 0)
+ continue;
+ ks += ptoa(KSTACK_GUARD_PAGES);
- return (ks);
+ /*
+ * Allocate physical pages to back the stack.
+ */
+ if (vm_thread_stack_back(ks, ma, pages, req, domain) != 0) {
+ vm_thread_free_kstack_kva(ks - ptoa(KSTACK_GUARD_PAGES),
+ ptoa(pages + KSTACK_GUARD_PAGES), domain);
+ continue;
+ }
+ if (KSTACK_GUARD_PAGES != 0) {
+ pmap_qremove(ks - ptoa(KSTACK_GUARD_PAGES),
+ KSTACK_GUARD_PAGES);
+ }
+ for (i = 0; i < pages; i++)
+ vm_page_valid(ma[i]);
+ pmap_qenter(ks, ma, pages);
+ return (ks);
+ } while (vm_domainset_iter_page(&di, obj, &domain) == 0);
+
+ return (0);
}
-static void
+static __noinline void
vm_thread_stack_dispose(vm_offset_t ks, int pages)
{
vm_page_t m;
vm_pindex_t pindex;
- int i;
-
- pindex = atop(ks - VM_MIN_KERNEL_ADDRESS);
+ int i, domain;
+ vm_object_t obj = vm_thread_kstack_size_to_obj(pages);
+ pindex = vm_kstack_pindex(ks, pages);
+ domain = vm_phys_domain(vtophys(ks));
pmap_qremove(ks, pages);
- VM_OBJECT_WLOCK(kstack_object);
+ VM_OBJECT_WLOCK(obj);
for (i = 0; i < pages; i++) {
- m = vm_page_lookup(kstack_object, pindex + i);
+ m = vm_page_lookup(obj, pindex + i);
if (m == NULL)
panic("%s: kstack already missing?", __func__);
+ KASSERT(vm_page_domain(m) == domain,
+ ("%s: page %p domain mismatch, expected %d got %d",
+ __func__, m, domain, vm_page_domain(m)));
vm_page_xbusy_claim(m);
vm_page_unwire_noq(m);
vm_page_free(m);
}
- VM_OBJECT_WUNLOCK(kstack_object);
+ VM_OBJECT_WUNLOCK(obj);
kasan_mark((void *)ks, ptoa(pages), ptoa(pages), 0);
- kva_free(ks - (KSTACK_GUARD_PAGES * PAGE_SIZE),
- (pages + KSTACK_GUARD_PAGES) * PAGE_SIZE);
+ vm_thread_free_kstack_kva(ks - (KSTACK_GUARD_PAGES * PAGE_SIZE),
+ ptoa(pages + KSTACK_GUARD_PAGES), domain);
}
/*
@@ -348,6 +514,7 @@ int
vm_thread_new(struct thread *td, int pages)
{
vm_offset_t ks;
+ u_short ks_domain;
/* Bounds check */
if (pages <= 1)
@@ -369,8 +536,13 @@ vm_thread_new(struct thread *td, int pages)
pages);
if (ks == 0)
return (0);
+
+ ks_domain = vm_phys_domain(vtophys(ks));
+ KASSERT(ks_domain >= 0 && ks_domain < vm_ndomains,
+ ("%s: invalid domain for kstack %p", __func__, (void *)ks));
td->td_kstack = ks;
td->td_kstack_pages = pages;
+ td->td_kstack_domain = ks_domain;
kasan_mark((void *)ks, ptoa(pages), ptoa(pages), 0);
kmsan_mark((void *)ks, ptoa(pages), KMSAN_STATE_UNINIT);
return (1);
@@ -389,6 +561,7 @@ vm_thread_dispose(struct thread *td)
ks = td->td_kstack;
td->td_kstack = 0;
td->td_kstack_pages = 0;
+ td->td_kstack_domain = MAXMEMDOM;
kasan_mark((void *)ks, 0, ptoa(pages), KASAN_KSTACK_FREED);
if (pages == kstack_pages)
uma_zfree(kstack_cache, (void *)ks);
@@ -396,33 +569,78 @@ vm_thread_dispose(struct thread *td)
vm_thread_stack_dispose(ks, pages);
}
+/*
+ * Calculate kstack pindex.
+ *
+ * Uses a non-identity mapping if guard pages are
+ * active to avoid pindex holes in the kstack object.
+ */
+vm_pindex_t
+vm_kstack_pindex(vm_offset_t ks, int kpages)
+{
+ vm_pindex_t pindex = atop(ks - VM_MIN_KERNEL_ADDRESS);
+
+#ifdef __ILP32__
+ return (pindex);
+#else
+ /*
+ * Return the linear pindex if guard pages aren't active or if we are
+ * allocating a non-standard kstack size.
+ */
+ if (KSTACK_GUARD_PAGES == 0 || kpages != kstack_pages) {
+ return (pindex);
+ }
+ KASSERT(pindex % (kpages + KSTACK_GUARD_PAGES) >= KSTACK_GUARD_PAGES,
+ ("%s: Attempting to calculate kstack guard page pindex", __func__));
+
+ return (pindex -
+ (pindex / (kpages + KSTACK_GUARD_PAGES) + 1) * KSTACK_GUARD_PAGES);
+#endif
+}
+
/*
* Allocate physical pages, following the specified NUMA policy, to back a
* kernel stack.
*/
-void
-vm_thread_stack_back(struct domainset *ds, vm_offset_t ks, vm_page_t ma[],
- int npages, int req_class)
+int
+vm_thread_stack_back(vm_offset_t ks, vm_page_t ma[], int npages, int req_class,
+ int domain)
{
+ vm_object_t obj = vm_thread_kstack_size_to_obj(npages);
vm_pindex_t pindex;
+ vm_page_t m;
int n;
- pindex = atop(ks - VM_MIN_KERNEL_ADDRESS);
+ pindex = vm_kstack_pindex(ks, npages);
- VM_OBJECT_WLOCK(kstack_object);
+ VM_OBJECT_WLOCK(obj);
for (n = 0; n < npages;) {
- if (vm_ndomains > 1)
- kstack_object->domain.dr_policy = ds;
-
- /*
- * Use WAITFAIL to force a reset of the domain selection policy
- * if we had to sleep for pages.
- */
- n += vm_page_grab_pages(kstack_object, pindex + n,
- req_class | VM_ALLOC_WIRED | VM_ALLOC_WAITFAIL,
- &ma[n], npages - n);
+ m = vm_page_grab(obj, pindex + n,
+ VM_ALLOC_NOCREAT | VM_ALLOC_WIRED);
+ if (m == NULL) {
+ m = vm_page_alloc_domain(obj, pindex + n, domain,
+ req_class | VM_ALLOC_WIRED);
+ }
+ if (m == NULL)
+ break;
+ ma[n++] = m;
}
- VM_OBJECT_WUNLOCK(kstack_object);
+ if (n < npages)
+ goto cleanup;
+ VM_OBJECT_WUNLOCK(obj);
+
+ return (0);
+cleanup:
+ vm_object_page_remove(obj, pindex, pindex + n, 0);
+ VM_OBJECT_WUNLOCK(obj);
+
+ return (ENOMEM);
+}
+
+vm_object_t
+vm_thread_kstack_size_to_obj(int npages)
+{
+ return (npages == kstack_pages ? kstack_object : kstack_alt_object);
}
static int
@@ -459,6 +677,9 @@ kstack_release(void *arg, void **store, int cnt)
static void
kstack_cache_init(void *null)
{
+ vm_size_t kstack_quantum;
+ int domain;
+
kstack_object = vm_object_allocate(OBJT_SWAP,
atop(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS));
kstack_cache = uma_zcache_create("kstack_cache",
@@ -467,6 +688,31 @@ kstack_cache_init(void *null)
UMA_ZONE_FIRSTTOUCH);
kstack_cache_size = imax(128, mp_ncpus * 4);
uma_zone_set_maxcache(kstack_cache, kstack_cache_size);
+
+ kstack_alt_object = vm_object_allocate(OBJT_SWAP,
+ atop(VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS));
+
+ kstack_quantum = vm_thread_kstack_import_quantum();
+ /*
+ * Reduce size used by the kstack arena to allow for
+ * alignment adjustments in vm_thread_kstack_arena_import.
+ */
+ kstack_quantum -= (kstack_pages + KSTACK_GUARD_PAGES) * PAGE_SIZE;
+ /*
+ * Create the kstack_arena for each domain and set kernel_arena as
+ * parent.
+ */
+ for (domain = 0; domain < vm_ndomains; domain++) {
+ vmd_kstack_arena[domain] = vmem_create("kstack arena", 0, 0,
+ PAGE_SIZE, 0, M_WAITOK);
+ KASSERT(vmd_kstack_arena[domain] != NULL,
+ ("%s: failed to create domain %d kstack_arena", __func__,
+ domain));
+ vmem_set_import(vmd_kstack_arena[domain],
+ vm_thread_kstack_arena_import,
+ vm_thread_kstack_arena_release,
+ vm_dom[domain].vmd_kernel_arena, kstack_quantum);
+ }
}
SYSINIT(vm_kstacks, SI_SUB_KMEM, SI_ORDER_ANY, kstack_cache_init, NULL);
diff --git a/sys/vm/vm_kern.h b/sys/vm/vm_kern.h
index a70f79f4ba3c..848f28fe90b8 100644
--- a/sys/vm/vm_kern.h
+++ b/sys/vm/vm_kern.h
@@ -76,6 +76,4 @@ extern struct vmem *memguard_arena;
extern u_long vm_kmem_size;
extern u_int exec_map_entries;
extern u_int exec_map_entry_size;
-extern vm_object_t kstack_object;
-
#endif /* _VM_VM_KERN_H_ */
diff --git a/sys/vm/vm_swapout.c b/sys/vm/vm_swapout.c
index fab25283a7e8..20b975f252e9 100644
--- a/sys/vm/vm_swapout.c
+++ b/sys/vm/vm_swapout.c
@@ -530,22 +530,24 @@ vm_thread_swapout(struct thread *td)
vm_offset_t kaddr;
vm_pindex_t pindex;
int i, pages;
+ vm_object_t obj;
cpu_thread_swapout(td);
kaddr = td->td_kstack;
pages = td->td_kstack_pages;
- pindex = atop(kaddr - VM_MIN_KERNEL_ADDRESS);
+ obj = vm_thread_kstack_size_to_obj(pages);
+ pindex = vm_kstack_pindex(kaddr, pages);
pmap_qremove(kaddr, pages);
- VM_OBJECT_WLOCK(kstack_object);
+ VM_OBJECT_WLOCK(obj);
for (i = 0; i < pages; i++) {
- m = vm_page_lookup(kstack_object, pindex + i);
+ m = vm_page_lookup(obj, pindex + i);
if (m == NULL)
panic("vm_thread_swapout: kstack already missing?");
vm_page_dirty(m);
vm_page_xunbusy_unchecked(m);
vm_page_unwire(m, PQ_LAUNDRY);
}
- VM_OBJECT_WUNLOCK(kstack_object);
+ VM_OBJECT_WUNLOCK(obj);
}
/*
@@ -556,31 +558,34 @@ vm_thread_swapin(struct thread *td, int oom_alloc)
{
vm_page_t ma[KSTACK_MAX_PAGES];
vm_offset_t kaddr;
+ vm_object_t obj;
int a, count, i, j, pages, rv __diagused;
kaddr = td->td_kstack;
pages = td->td_kstack_pages;
- vm_thread_stack_back(td->td_domain.dr_policy, kaddr, ma, pages,
- oom_alloc);
+ obj = vm_thread_kstack_size_to_obj(pages);
+ while (vm_thread_stack_back(kaddr, ma, pages, oom_alloc,
+ td->td_kstack_domain) == ENOMEM)
+ ;
for (i = 0; i < pages;) {
vm_page_assert_xbusied(ma[i]);
if (vm_page_all_valid(ma[i])) {
i++;
continue;
}
- vm_object_pip_add(kstack_object, 1);
+ vm_object_pip_add(obj, 1);
for (j = i + 1; j < pages; j++)
if (vm_page_all_valid(ma[j]))
break;
- VM_OBJECT_WLOCK(kstack_object);
- rv = vm_pager_has_page(kstack_object, ma[i]->pindex, NULL, &a);
- VM_OBJECT_WUNLOCK(kstack_object);
+ VM_OBJECT_WLOCK(obj);
+ rv = vm_pager_has_page(obj, ma[i]->pindex, NULL, &a);
+ VM_OBJECT_WUNLOCK(obj);
KASSERT(rv == 1, ("%s: missing page %p", __func__, ma[i]));
count = min(a + 1, j - i);
- rv = vm_pager_get_pages(kstack_object, ma + i, count, NULL, NULL);
+ rv = vm_pager_get_pages(obj, ma + i, count, NULL, NULL);
KASSERT(rv == VM_PAGER_OK, ("%s: cannot get kstack for proc %d",
__func__, td->td_proc->p_pid));
- vm_object_pip_wakeup(kstack_object);
+ vm_object_pip_wakeup(obj);
i += count;
}
pmap_qenter(kaddr, ma, pages);