commit 840c3b15ddf9d58cff1ce458cc3fddab3e368254
Author: Justus Winter <4winter@informatik.uni-hamburg.de>
Date:   Sun Apr 27 09:16:40 2014 +0200

    libpager: make libpager single-threaded
    
    * console/pager.c (
    * ext2fs/pager.c
    * libdiskfs/disk-pager.c
    * storeio/pager.c
    
    * libpager/Makefile: Likewise.
    * libpager/chg-compl.c: Likewise.
    * libpager/data-request.c: Likewise.
    * libpager/data-return.c: Likewise.
    * libpager/data-unlock.c: Likewise.
    * libpager/demuxer.c: Likewise.
    * libpager/lock-completed.c: Likewise.
    * libpager/no-senders.c: Likewise.
    * libpager/notify-stubs.c: Likewise.
    * libpager/object-init.c: Likewise.
    * libpager/object-terminate.c: Likewise.
    * libpager/pager-create.c: Likewise.
    * libpager/priv.h: Likewise.
    * libpager/seqnos.c: Likewise.
    * libpager/stubs.c: Likewise.
    * libpager/seqnos.c: Remove unused file.

diff --git a/console/pager.c b/console/pager.c
index 87c36f0..e40ae45 100644
--- a/console/pager.c
+++ b/console/pager.c
@@ -127,11 +127,10 @@ static void *
 service_paging_requests (void *arg)
 {
   struct port_bucket *pager_bucket = arg;
-  for (;;)
-    ports_manage_port_operations_multithread (pager_bucket,
-                                              pager_demuxer,
-                                              1000 * 60 * 2,
-                                              1000 * 60 * 10, 0);
+  ports_manage_port_operations_one_thread (pager_bucket,
+					   pager_demuxer,
+					   0);
+  /* Not reached.  */
   return NULL;
 }    
 
diff --git a/ext2fs/pager.c b/ext2fs/pager.c
index f3e9489..febde8f 100644
--- a/ext2fs/pager.c
+++ b/ext2fs/pager.c
@@ -1198,11 +1198,9 @@ static void *
 service_paging_requests (void *arg)
 {
   struct port_bucket *pager_bucket = arg;
-  ports_manage_port_operations_multithread (pager_bucket,
-					    pager_demuxer,
-					    1000,
-					    0,
-					    NULL);
+  ports_manage_port_operations_one_thread (pager_bucket,
+					   pager_demuxer,
+					   0);
   /* Not reached.  */
   return NULL;
 }
diff --git a/libdiskfs/disk-pager.c b/libdiskfs/disk-pager.c
index 9a0d9d8..6746d4c 100644
--- a/libdiskfs/disk-pager.c
+++ b/libdiskfs/disk-pager.c
@@ -39,11 +39,10 @@ static void *
 service_paging_requests (void *arg)
 {
   struct port_bucket *pager_bucket = arg;
-  for (;;)
-    ports_manage_port_operations_multithread (pager_bucket,
-					      pager_demuxer,
-					      1000 * 60 * 2,
-					      1000 * 60 * 10, 0);
+  ports_manage_port_operations_one_thread (pager_bucket,
+					   pager_demuxer,
+					   0);
+  /* Not reached.  */
   return NULL;
 }
 
diff --git a/libpager/Makefile b/libpager/Makefile
index b622295..a15a899 100644
--- a/libpager/Makefile
+++ b/libpager/Makefile
@@ -22,7 +22,7 @@ SRCS = data-request.c data-return.c data-unlock.c pager-port.c \
 	inhibit-term.c lock-completed.c lock-object.c mark-error.c \
 	no-senders.c object-init.c object-terminate.c pagemap.c \
 	pager-create.c pager-flush.c pager-shutdown.c pager-sync.c \
-	stubs.c seqnos.c demuxer.c chg-compl.c pager-attr.c clean.c \
+	stubs.c demuxer.c chg-compl.c pager-attr.c clean.c \
 	dropweak.c notify-stubs.c get-upi.c pager-memcpy.c pager-return.c \
 	offer-page.c
 installhdrs = pager.h
diff --git a/libpager/chg-compl.c b/libpager/chg-compl.c
index d77c46c..89ccfc8 100644
--- a/libpager/chg-compl.c
+++ b/libpager/chg-compl.c
@@ -37,7 +37,6 @@ _pager_seqnos_memory_object_change_completed (struct pager *p,
     }
   
   pthread_mutex_lock (&p->interlock);
-  _pager_wait_for_seqno (p, seq);
 
   for (ar = p->attribute_requests; ar; ar = ar->next)
     if (ar->may_cache == maycache && ar->copy_strategy == strat)
@@ -46,8 +45,7 @@ _pager_seqnos_memory_object_change_completed (struct pager *p,
 	  pthread_cond_broadcast (&p->wakeup);
 	break;
       }
-  
-  _pager_release_seqno (p, seq);
+
   pthread_mutex_unlock (&p->interlock);
   return 0;
 }
diff --git a/libpager/data-request.c b/libpager/data-request.c
index 82ce904..18f3de6 100644
--- a/libpager/data-request.c
+++ b/libpager/data-request.c
@@ -41,7 +41,6 @@ _pager_seqnos_memory_object_data_request (struct pager *p,
 
   /* Acquire the right to meddle with the pagemap */
   pthread_mutex_lock (&p->interlock);
-  _pager_wait_for_seqno (p, seqno);
 
   /* sanity checks -- we don't do multi-page requests yet.  */
   if (control != p->memobjcntl)
@@ -105,7 +104,6 @@ _pager_seqnos_memory_object_data_request (struct pager *p,
     }
 
   /* Let someone else in.  */
-  _pager_release_seqno (p, seqno);
   pthread_mutex_unlock (&p->interlock);
 
   if (!doread)
@@ -139,7 +137,6 @@ _pager_seqnos_memory_object_data_request (struct pager *p,
  allow_release_out:
   _pager_allow_termination (p);
  release_out:
-  _pager_release_seqno (p, seqno);
   pthread_mutex_unlock (&p->interlock);
   return 0;
 }
diff --git a/libpager/data-return.c b/libpager/data-return.c
index ee6c6e8..f16f323 100644
--- a/libpager/data-return.c
+++ b/libpager/data-return.c
@@ -52,7 +52,6 @@ _pager_do_write_request (struct pager *p,
 
   /* Acquire the right to meddle with the pagemap */
   pthread_mutex_lock (&p->interlock);
-  _pager_wait_for_seqno (p, seqno);
 
   /* sanity checks -- we don't do multi-page requests yet.  */
   if (control != p->memobjcntl)
@@ -101,7 +100,6 @@ _pager_do_write_request (struct pager *p,
           notified[i] = (p->notify_on_evict
                          && ! (pm_entries[i] & PM_PAGEINWAIT));
 
-        _pager_release_seqno (p, seqno);
         goto notify;
       }
       else {
@@ -158,7 +156,6 @@ _pager_do_write_request (struct pager *p,
       }
 
   /* Let someone else in. */
-  _pager_release_seqno (p, seqno);
   pthread_mutex_unlock (&p->interlock);
 
   /* This is inefficient; we should send all the pages to the device at once
@@ -251,7 +248,6 @@ _pager_do_write_request (struct pager *p,
   return 0;
 
  release_out:
-  _pager_release_seqno (p, seqno);
   pthread_mutex_unlock (&p->interlock);
   return 0;
 }
diff --git a/libpager/data-unlock.c b/libpager/data-unlock.c
index 599237c..8c7c776 100644
--- a/libpager/data-unlock.c
+++ b/libpager/data-unlock.c
@@ -35,11 +35,6 @@ _pager_seqnos_memory_object_data_unlock (struct pager *p,
       || p->port.class != _pager_class)
     return EOPNOTSUPP;
 
-  pthread_mutex_lock (&p->interlock);
-  _pager_wait_for_seqno (p, seqno);
-  _pager_release_seqno (p, seqno);
-  pthread_mutex_unlock (&p->interlock);
-
   if (p->pager_state != NORMAL)
     {
       printf ("pager in wrong state for unlock\n");
diff --git a/libpager/demuxer.c b/libpager/demuxer.c
index b4d4054..90edf1d 100644
--- a/libpager/demuxer.c
+++ b/libpager/demuxer.c
@@ -33,8 +33,5 @@ pager_demuxer (mach_msg_header_t *inp,
       return TRUE;
     }
 
-  /* Synchronize our bookkeeping of the port's seqno with the one
-     consumed by this bogus message.  */
-  _pager_update_seqno (inp->msgh_local_port, inp->msgh_seqno);
   return FALSE;
 }
diff --git a/libpager/lock-completed.c b/libpager/lock-completed.c
index a3f3f16..30b1dd3 100644
--- a/libpager/lock-completed.c
+++ b/libpager/lock-completed.c
@@ -37,7 +37,6 @@ _pager_seqnos_memory_object_lock_completed (struct pager *p,
     return EOPNOTSUPP;
 
   pthread_mutex_lock (&p->interlock);
-  _pager_wait_for_seqno (p, seqno);
 
   if (control != p->memobjcntl)
     {
@@ -59,7 +58,6 @@ _pager_seqnos_memory_object_lock_completed (struct pager *p,
       }
       
  out:
-  _pager_release_seqno (p, seqno);
   pthread_mutex_unlock (&p->interlock);
 
   return err;
diff --git a/libpager/no-senders.c b/libpager/no-senders.c
index c21dfc2..d0bbe27 100644
--- a/libpager/no-senders.c
+++ b/libpager/no-senders.c
@@ -29,7 +29,6 @@ _pager_do_seqnos_mach_notify_no_senders (struct port_info *pi,
       pi->class != _pager_class)
     return EOPNOTSUPP;
 
-  _pager_update_seqno_p ((struct pager *) pi, seqno);
   ports_no_senders (pi, mscount);
 
   return 0;
diff --git a/libpager/notify-stubs.c b/libpager/notify-stubs.c
index ba13882..a826420 100644
--- a/libpager/notify-stubs.c
+++ b/libpager/notify-stubs.c
@@ -28,8 +28,6 @@ _pager_do_seqnos_mach_notify_port_deleted (struct port_info *pi,
 					   mach_port_t name
 					   __attribute__ ((unused)))
 {
-  _pager_update_seqno_p ((struct pager *) pi, seqno);
-
   return 0;
 }
 
@@ -39,8 +37,6 @@ _pager_do_seqnos_mach_notify_msg_accepted (struct port_info *pi,
 					   mach_port_t name
 					     __attribute__ ((unused)))
 {
-  _pager_update_seqno_p ((struct pager *) pi, seqno);
-
   return 0;
 }
 
@@ -50,8 +46,6 @@ _pager_do_seqnos_mach_notify_port_destroyed (struct port_info *pi,
 					     mach_port_t name
 					       __attribute__ ((unused)))
 {
-  _pager_update_seqno_p ((struct pager *) pi, seqno);
-
   return 0;
 }
 
@@ -59,8 +53,6 @@ error_t
 _pager_do_seqnos_mach_notify_send_once (struct port_info *pi,
 					mach_port_seqno_t seqno)
 {
-  _pager_update_seqno_p ((struct pager *) pi, seqno);
-
   return 0;
 }
 
@@ -70,7 +62,5 @@ _pager_do_seqnos_mach_notify_dead_name (struct port_info *pi,
 					mach_port_t name
 					  __attribute__ ((unused)))
 {
-  _pager_update_seqno_p ((struct pager *) pi, seqno);
-
   return 0;
 }
diff --git a/libpager/object-init.c b/libpager/object-init.c
index 6683e24..eb62c44 100644
--- a/libpager/object-init.c
+++ b/libpager/object-init.c
@@ -33,7 +33,6 @@ _pager_seqnos_memory_object_init (struct pager *p,
     return EOPNOTSUPP;
 
   pthread_mutex_lock (&p->interlock);
-  _pager_wait_for_seqno (p, seqno);
 
   if (pagesize != __vm_page_size)
     {
@@ -69,7 +68,6 @@ _pager_seqnos_memory_object_init (struct pager *p,
   p->pager_state = NORMAL;
 
  out:
-  _pager_release_seqno (p, seqno);
   pthread_mutex_unlock (&p->interlock);
 
   return 0;
diff --git a/libpager/object-terminate.c b/libpager/object-terminate.c
index 365ba27..3f0482f 100644
--- a/libpager/object-terminate.c
+++ b/libpager/object-terminate.c
@@ -32,8 +32,7 @@ _pager_seqnos_memory_object_terminate (struct pager *p,
     return EOPNOTSUPP;
 
   pthread_mutex_lock (&p->interlock);
-  _pager_wait_for_seqno (p, seqno);
-  
+
   if (control != p->memobjcntl)
     {
       printf ("incg terminate: wrong control port");
@@ -75,7 +74,6 @@ _pager_seqnos_memory_object_terminate (struct pager *p,
 #endif
 
  out:
-  _pager_release_seqno (p, seqno);
   pthread_mutex_unlock (&p->interlock);
 
   return 0;
diff --git a/libpager/pager-create.c b/libpager/pager-create.c
index 1fc15b8..b583f02 100644
--- a/libpager/pager-create.c
+++ b/libpager/pager-create.c
@@ -42,10 +42,8 @@ pager_create (struct user_pager_info *upi,
   p->notify_on_evict = notify_on_evict;
   p->memobjcntl = MACH_PORT_NULL;
   p->memobjname = MACH_PORT_NULL;
-  p->seqno = -1;
   p->noterm = 0;
   p->termwaiting = 0;
-  p->waitingforseqno = 0;
   p->pagemap = 0;
   p->pagemapsize = 0;
 
diff --git a/libpager/priv.h b/libpager/priv.h
index d49cbb9..dc2f908 100644
--- a/libpager/priv.h
+++ b/libpager/priv.h
@@ -55,14 +55,11 @@ struct pager
   memory_object_control_t memobjcntl;
   memory_object_name_t memobjname;
 
-  mach_port_seqno_t seqno;
-
   int noterm;			/* number of threads blocking termination */
 
   struct pager *next, **pprev;
 
   int termwaiting:1;
-  int waitingforseqno:1;
 
 #ifdef KERNEL_INIT_RACE
   /* Out of sequence object_init calls waiting for
@@ -136,10 +133,6 @@ extern int _pager_page_errors[];
 struct port_class *_pager_class;
 
 
-void _pager_wait_for_seqno (struct pager *, mach_port_seqno_t);
-void _pager_release_seqno (struct pager *, mach_port_seqno_t);
-void _pager_update_seqno (mach_port_t, mach_port_seqno_t);
-void _pager_update_seqno_p (struct pager *, mach_port_seqno_t);
 void _pager_block_termination (struct pager *);
 void _pager_allow_termination (struct pager *);
 error_t _pager_pagemap_resize (struct pager *, vm_address_t);
diff --git a/libpager/seqnos.c b/libpager/seqnos.c
deleted file mode 100644
index cab2f33..0000000
--- a/libpager/seqnos.c
+++ /dev/null
@@ -1,79 +0,0 @@
-/* Sequence number synchronization routines for pager library
-   Copyright (C) 1994, 2011 Free Software Foundation
-
-   This program is free software; you can redistribute it and/or
-   modify it under the terms of the GNU General Public License as
-   published by the Free Software Foundation; either version 2, or (at
-   your option) any later version.
-
-   This program is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software
-   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
-
-#include "priv.h"
-#include <assert.h>
-
-/* The message with seqno SEQNO has just been dequeued for pager P;
-   wait until all preceding messages have had a chance and then
-   return.  */
-void
-_pager_wait_for_seqno (struct pager *p,
-		       mach_port_seqno_t seqno)
-{
-  while (seqno != p->seqno + 1)
-    {
-      p->waitingforseqno = 1;
-      pthread_cond_wait (&p->wakeup, &p->interlock);
-    }
-}
-
-
-/* Allow the next message for pager P (potentially blocked in
-   _pager_wait_for_seqno) to be handled.  */
-void
-_pager_release_seqno (struct pager *p,
-		      mach_port_seqno_t seqno)
-{
-  assert (seqno == p->seqno + 1);
-  p->seqno = seqno;
-  if (p->waitingforseqno)
-    {
-      p->waitingforseqno = 0;
-      pthread_cond_broadcast (&p->wakeup);
-    }
-}
-
-
-/* Just update the seqno.  */
-void
-_pager_update_seqno (mach_port_t object,
-                     mach_port_seqno_t seqno)
-{
-  struct pager *p;
-
-  p = ports_lookup_port (0, object, _pager_class);
-  _pager_update_seqno_p (p, seqno);
-  if (p)
-    ports_port_deref (p);
-}
-
-
-/* Just update the seqno, pointer version.  */
-void
-_pager_update_seqno_p (struct pager *p,
-                       mach_port_seqno_t seqno)
-{
-  if (p
-      && p->port.class == _pager_class)
-    {
-      pthread_mutex_lock (&p->interlock);
-      _pager_wait_for_seqno (p, seqno);
-      _pager_release_seqno (p, seqno);
-      pthread_mutex_unlock (&p->interlock);
-    }
-}
diff --git a/libpager/stubs.c b/libpager/stubs.c
index 411f483..c7f1a5a 100644
--- a/libpager/stubs.c
+++ b/libpager/stubs.c
@@ -29,9 +29,6 @@ _pager_seqnos_memory_object_copy (struct pager *p,
 			   mach_port_t new)
 {
   printf ("m_o_copy called\n");
-
-  _pager_update_seqno_p (p, seq);
-
   return EOPNOTSUPP;
 }
 
@@ -44,9 +41,6 @@ _pager_seqnos_memory_object_data_write (struct pager *p,
 				 vm_size_t data_cnt)
 {
   printf ("m_o_data_write called\n");
-
-  _pager_update_seqno_p (p, seq);
-
   return EOPNOTSUPP;
 }
 
@@ -60,8 +54,5 @@ _pager_seqnos_memory_object_supply_completed (struct pager *p,
 				       vm_offset_t err_off)
 {
   printf ("m_o_supply_completed called\n");
-
-  _pager_update_seqno_p (p, seq);
-
   return EOPNOTSUPP;
 }
diff --git a/storeio/pager.c b/storeio/pager.c
index 7d78711..4f86407 100644
--- a/storeio/pager.c
+++ b/storeio/pager.c
@@ -148,12 +148,10 @@ static void *
 service_paging_requests (void *arg)
 {
   (void) arg;
-
-  for (;;)
-    ports_manage_port_operations_multithread (pager_port_bucket,
-					      pager_demuxer,
-					      1000 * 30, 1000 * 60 * 5, 0);
-
+  ports_manage_port_operations_one_thread (pager_port_bucket,
+					   pager_demuxer,
+					   0);
+  /* Not reached.  */
   return NULL;
 }