[src/trunk]: src/sys/rump/librump/rumpkern Implement a sort-of pagedaemon: ad...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/8db303588829
branches:  trunk
changeset: 755371:8db303588829
user:      pooka <pooka%NetBSD.org@localhost>
date:      Thu Jun 03 10:56:20 2010 +0000

description:
Implement a sort-of pagedaemon: adjust all memory allocators to go
through an in-rumpkernel hypermemory allocator which knows it should
kick the pagedaemon and block in case ``waitok'' memory allocation
fails.

This allows us to recover from some out-of-memory situations.
Realworld'istically speaking (as opposed to whatever "should be"
theory), these OOM situations will happen extremely rarely if ever
when our hypervisor is a regular process.  Speculatively, this
should be useful for other types of hosts.

issues remaining:
 * the hypervisor does not know how to reclaim kernel memory (and
   for the reason I stated above, I'm not sure if it makes sense
   to teach the current implementation about that)
 * vfs memory (buffers, vm object pages etc.) is not reclaimed

diffstat:

 sys/rump/librump/rumpkern/locks_up.c     |    8 +-
 sys/rump/librump/rumpkern/memalloc.c     |   30 +++-
 sys/rump/librump/rumpkern/rump.c         |   14 ++-
 sys/rump/librump/rumpkern/rump_private.h |    4 +-
 sys/rump/librump/rumpkern/vm.c           |  181 ++++++++++++++++++++++++------
 5 files changed, 183 insertions(+), 54 deletions(-)

diffs (truncated from 425 to 300 lines):

diff -r 8bb265a4151e -r 8db303588829 sys/rump/librump/rumpkern/locks_up.c
--- a/sys/rump/librump/rumpkern/locks_up.c      Thu Jun 03 10:44:21 2010 +0000
+++ b/sys/rump/librump/rumpkern/locks_up.c      Thu Jun 03 10:56:20 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: locks_up.c,v 1.2 2010/06/01 20:11:33 pooka Exp $       */
+/*     $NetBSD: locks_up.c,v 1.3 2010/06/03 10:56:20 pooka Exp $       */
 
 /*
  * Copyright (c) 2010 Antti Kantee.  All Rights Reserved.
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: locks_up.c,v 1.2 2010/06/01 20:11:33 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: locks_up.c,v 1.3 2010/06/03 10:56:20 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -74,7 +74,7 @@
         * XXX: pool_cache would be nice, but not easily possible,
         * as pool cache init wants to call mutex_init() ...
         */
-       upm = rumpuser_malloc(sizeof(*upm), 0);
+       upm = rump_hypermalloc(sizeof(*upm), 0, true, "mutex_init");
        memset(upm, 0, sizeof(*upm));
        rumpuser_cv_init(&upm->upm_rucv);
        memcpy(mtx, &upm, sizeof(void *));
@@ -178,7 +178,7 @@
        CTASSERT(sizeof(krwlock_t) >= sizeof(void *));
        checkncpu();
 
-       uprw = rumpuser_malloc(sizeof(*uprw), 0);
+       uprw = rump_hypermalloc(sizeof(*uprw), 0, true, "rwinit");
        memset(uprw, 0, sizeof(*uprw));
        rumpuser_cv_init(&uprw->uprw_rucv_reader);
        rumpuser_cv_init(&uprw->uprw_rucv_writer);
diff -r 8bb265a4151e -r 8db303588829 sys/rump/librump/rumpkern/memalloc.c
--- a/sys/rump/librump/rumpkern/memalloc.c      Thu Jun 03 10:44:21 2010 +0000
+++ b/sys/rump/librump/rumpkern/memalloc.c      Thu Jun 03 10:56:20 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: memalloc.c,v 1.6 2010/06/01 20:11:33 pooka Exp $       */
+/*     $NetBSD: memalloc.c,v 1.7 2010/06/03 10:56:20 pooka Exp $       */
 
 /*
  * Copyright (c) 2009 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: memalloc.c,v 1.6 2010/06/01 20:11:33 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: memalloc.c,v 1.7 2010/06/03 10:56:20 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/kmem.h>
@@ -73,7 +73,7 @@
 {
        void *rv;
 
-       rv = rumpuser_malloc(size, 0);
+       rv = rump_hypermalloc(size, 0, (flags & M_WAITOK) != 0, "malloc");
        if (rv && flags & M_ZERO)
                memset(rv, 0, size);
 
@@ -110,7 +110,7 @@
 kmem_alloc(size_t size, km_flag_t kmflag)
 {
 
-       return rumpuser_malloc(size, 0);
+       return rump_hypermalloc(size, 0, kmflag == KM_SLEEP, "kmem_alloc");
 }
 
 void *
@@ -240,18 +240,14 @@
 void *
 pool_get(struct pool *pp, int flags)
 {
-       void *rv;
 
 #ifdef DIAGNOSTIC
        if (pp->pr_size == 0)
                panic("%s: pool unit size 0.  not initialized?", __func__);
 #endif
 
-       rv = rumpuser_malloc(pp->pr_size, pp->pr_align);
-       if (rv == NULL && (flags & PR_WAITOK && (flags & PR_LIMITFAIL) == 0))
-               panic("%s: out of memory and PR_WAITOK", __func__);
-
-       return rv;
+       return rump_hypermalloc(pp->pr_size, pp->pr_align,
+           (flags & PR_WAITOK) != 0, "pget");
 }
 
 void
@@ -299,6 +295,20 @@
        pc->pc_pool.pr_drain_hook_arg = arg;
 }
 
+void
+pool_drain_start(struct pool **ppp, uint64_t *wp)
+{
+
+       /* nada */
+}
+
+void
+pool_drain_end(struct pool *pp, uint64_t w)
+{
+
+       /* nada again */
+}
+
 int
 pool_prime(struct pool *pp, int nitems)
 {
diff -r 8bb265a4151e -r 8db303588829 sys/rump/librump/rumpkern/rump.c
--- a/sys/rump/librump/rumpkern/rump.c  Thu Jun 03 10:44:21 2010 +0000
+++ b/sys/rump/librump/rumpkern/rump.c  Thu Jun 03 10:56:20 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rump.c,v 1.174 2010/06/02 10:55:18 pooka Exp $ */
+/*     $NetBSD: rump.c,v 1.175 2010/06/03 10:56:20 pooka Exp $ */
 
 /*
  * Copyright (c) 2007 Antti Kantee.  All Rights Reserved.
@@ -28,7 +28,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rump.c,v 1.174 2010/06/02 10:55:18 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rump.c,v 1.175 2010/06/03 10:56:20 pooka Exp $");
 
 #include <sys/systm.h>
 #define ELFSIZE ARCH_ELFSIZE
@@ -49,6 +49,7 @@
 #include <sys/kernel.h>
 #include <sys/kmem.h>
 #include <sys/kprintf.h>
+#include <sys/kthread.h>
 #include <sys/ksyms.h>
 #include <sys/msgbuf.h>
 #include <sys/module.h>
@@ -357,6 +358,15 @@
        pipe_init();
        resource_init();
 
+       /* start page baroness */
+       if (rump_threads) {
+               if (kthread_create(PRI_PGDAEMON, KTHREAD_MPSAFE, NULL,
+                   uvm_pageout, NULL, &uvm.pagedaemon_lwp, "pdaemon") != 0)
+                       panic("pagedaemon create failed");
+       } else
+               uvm.pagedaemon_lwp = NULL; /* doesn't match curlwp */
+
+       /* process dso's */
        rumpuser_dl_bootstrap(add_linkedin_modules, rump_kernelfsym_load);
 
        /* these do nothing if not present */
diff -r 8bb265a4151e -r 8db303588829 sys/rump/librump/rumpkern/rump_private.h
--- a/sys/rump/librump/rumpkern/rump_private.h  Thu Jun 03 10:44:21 2010 +0000
+++ b/sys/rump/librump/rumpkern/rump_private.h  Thu Jun 03 10:56:20 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rump_private.h,v 1.49 2010/06/02 10:55:18 pooka Exp $  */
+/*     $NetBSD: rump_private.h,v 1.50 2010/06/03 10:56:20 pooka Exp $  */
 
 /*
  * Copyright (c) 2007 Antti Kantee.  All Rights Reserved.
@@ -129,4 +129,6 @@
 void   rump_intr_init(void);
 void   rump_softint_run(struct cpu_info *);
 
+void   *rump_hypermalloc(size_t, int, bool, const char *);
+
 #endif /* _SYS_RUMP_PRIVATE_H_ */
diff -r 8bb265a4151e -r 8db303588829 sys/rump/librump/rumpkern/vm.c
--- a/sys/rump/librump/rumpkern/vm.c    Thu Jun 03 10:44:21 2010 +0000
+++ b/sys/rump/librump/rumpkern/vm.c    Thu Jun 03 10:56:20 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vm.c,v 1.79 2010/06/02 10:55:18 pooka Exp $    */
+/*     $NetBSD: vm.c,v 1.80 2010/06/03 10:56:20 pooka Exp $    */
 
 /*
  * Copyright (c) 2007-2010 Antti Kantee.  All Rights Reserved.
@@ -43,15 +43,16 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vm.c,v 1.79 2010/06/02 10:55:18 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vm.c,v 1.80 2010/06/03 10:56:20 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/atomic.h>
+#include <sys/buf.h>
+#include <sys/kernel.h>
 #include <sys/kmem.h>
 #include <sys/mman.h>
 #include <sys/null.h>
 #include <sys/vnode.h>
-#include <sys/buf.h>
 
 #include <machine/pmap.h>
 
@@ -87,6 +88,10 @@
 static struct vm_map_kernel kernel_map_store;
 struct vm_map *kernel_map = &kernel_map_store.vmk_map;
 
+static unsigned int pdaemon_waiters;
+static kmutex_t pdaemonmtx;
+static kcondvar_t pdaemoncv, oomwait;
+
 /*
  * vm pages 
  */
@@ -233,12 +238,15 @@
 {
 
        uvmexp.free = 1024*1024; /* XXX */
-       uvm.pagedaemon_lwp = NULL; /* doesn't match curlwp */
        rump_vmspace.vm_map.pmap = pmap_kernel();
 
        mutex_init(&pagermtx, MUTEX_DEFAULT, 0);
        mutex_init(&uvm_pageqlock, MUTEX_DEFAULT, 0);
 
+       mutex_init(&pdaemonmtx, MUTEX_DEFAULT, 0);
+       cv_init(&pdaemoncv, "pdaemon");
+       cv_init(&oomwait, "oomwait");
+
        kernel_map->pmap = pmap_kernel();
        callback_head_init(&kernel_map_store.vmk_reclaim_callback, IPL_VM);
        kmem_map->pmap = pmap_kernel();
@@ -460,31 +468,10 @@
 vm_map_starved_p(struct vm_map *map)
 {
 
-       return false;
-}
-
-void
-uvm_pageout_start(int npages)
-{
-
-       uvmexp.paging += npages;
-}
+       if (map->flags & VM_MAP_WANTVA)
+               return true;
 
-void
-uvm_pageout_done(int npages)
-{
-
-       uvmexp.paging -= npages;
-
-       /*
-        * wake up either of pagedaemon or LWPs waiting for it.
-        */
-
-       if (uvmexp.free <= uvmexp.reserve_kernel) {
-               wakeup(&uvm.pagedaemon);
-       } else {
-               wakeup(&uvmexp.free);
-       }
+       return false;
 }
 
 int
@@ -582,14 +569,15 @@
 uvm_km_alloc_poolpage(struct vm_map *map, bool waitok)
 {
 
-       return (vaddr_t)rumpuser_malloc(PAGE_SIZE, PAGE_SIZE);
+       return (vaddr_t)rump_hypermalloc(PAGE_SIZE, PAGE_SIZE,
+           waitok, "kmalloc");
 }
 
 void
 uvm_km_free_poolpage(struct vm_map *map, vaddr_t addr)
 {
 
-       rumpuser_unmap((void *)addr, PAGE_SIZE);
+       rumpuser_free((void *)addr);
 }
 
 vaddr_t
@@ -648,13 +636,6 @@
 }
 
 void
-uvm_wait(const char *msg)
-{
-
-       /* nothing to wait for */
-}
-
-void
 uvmspace_free(struct vmspace *vm)
 {
 
@@ -703,3 +684,129 @@
 
        /* nada */
 }
+