Lock the page queues by turning uvm_lock_pageq() and uvm_unlock_pageq() into

mtx_enter() and mtx_leave() operations.  Not 100% this won't blow up but
there is only one way to find out, and we need this to make progress on
further unlocking uvm.

prodded by deraadt@

diff --git a/sys/uvm/uvm.h b/sys/uvm/uvm.h
index bc42871..5a6082d 100644 (file)
--- a/sys/uvm/uvm.h
+++ b/sys/uvm/uvm.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm.h,v 1.59 2015/05/04 10:21:15 dlg Exp $    */
+/*     $OpenBSD: uvm.h,v 1.60 2015/10/08 15:58:38 kettenis Exp $       */
 /*     $NetBSD: uvm.h,v 1.24 2000/11/27 08:40:02 chs Exp $     */
 
 /*
@@ -54,6 +54,7 @@ struct uvm {
        struct pglist page_inactive_swp;/* pages inactive (reclaim or free) */
        struct pglist page_inactive_obj;/* pages inactive (reclaim or free) */
        /* Lock order: pageqlock, then fpageqlock. */
+       struct mutex pageqlock;         /* lock for active/inactive page q */
        struct mutex fpageqlock;        /* lock for free page q  + pdaemon */
        boolean_t page_init_done;       /* TRUE if uvm_page_init() finished */
        struct uvm_pmr_control pmr_control; /* pmemrange data */

diff --git a/sys/uvm/uvm_page.c b/sys/uvm/uvm_page.c
index 84be6eb..0816005 100644 (file)
--- a/sys/uvm/uvm_page.c
+++ b/sys/uvm/uvm_page.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_page.c,v 1.142 2015/09/21 12:59:01 visa Exp $     */
+/*     $OpenBSD: uvm_page.c,v 1.143 2015/10/08 15:58:38 kettenis Exp $ */
 /*     $NetBSD: uvm_page.c,v 1.44 2000/11/27 08:40:04 chs Exp $        */
 
 /*
@@ -179,6 +179,7 @@ uvm_page_init(vaddr_t *kvm_startp, vaddr_t *kvm_endp)
        TAILQ_INIT(&uvm.page_active);
        TAILQ_INIT(&uvm.page_inactive_swp);
        TAILQ_INIT(&uvm.page_inactive_obj);
+       mtx_init(&uvm.pageqlock, IPL_NONE);
        mtx_init(&uvm.fpageqlock, IPL_VM);
        uvm_pmr_init();
 

diff --git a/sys/uvm/uvm_page.h b/sys/uvm/uvm_page.h
index aaf0318..1300b3b 100644 (file)
--- a/sys/uvm/uvm_page.h
+++ b/sys/uvm/uvm_page.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_page.h,v 1.59 2015/08/21 16:04:35 visa Exp $      */
+/*     $OpenBSD: uvm_page.h,v 1.60 2015/10/08 15:58:38 kettenis Exp $  */
 /*     $NetBSD: uvm_page.h,v 1.19 2000/12/28 08:24:55 chs Exp $        */
 
 /* 
@@ -285,8 +285,8 @@ int         vm_physseg_find(paddr_t, int *);
  * macros
  */
 
-#define uvm_lock_pageq()       /* lock */
-#define uvm_unlock_pageq()     /* unlock */
+#define uvm_lock_pageq()       mtx_enter(&uvm.pageqlock)
+#define uvm_unlock_pageq()     mtx_leave(&uvm.pageqlock)
 #define uvm_lock_fpageq()      mtx_enter(&uvm.fpageqlock)
 #define uvm_unlock_fpageq()    mtx_leave(&uvm.fpageqlock)
 

diff --git a/sys/uvm/uvm_pdaemon.c b/sys/uvm/uvm_pdaemon.c
index ea89617..15dba9c 100644 (file)
--- a/sys/uvm/uvm_pdaemon.c
+++ b/sys/uvm/uvm_pdaemon.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_pdaemon.c,v 1.76 2015/08/21 16:04:35 visa Exp $   */
+/*     $OpenBSD: uvm_pdaemon.c,v 1.77 2015/10/08 15:58:38 kettenis Exp $       */
 /*     $NetBSD: uvm_pdaemon.c,v 1.23 2000/08/20 10:24:14 bjh21 Exp $   */
 
 /* 
@@ -237,7 +237,9 @@ uvm_pageout(void *arg)
                if (uvmexp.free - BUFPAGES_DEFICIT < uvmexp.freetarg)
                        size += uvmexp.freetarg - (uvmexp.free -
                            BUFPAGES_DEFICIT);
+               uvm_unlock_pageq();
                (void) bufbackoff(&constraint, size * 2);
+               uvm_lock_pageq();
 
                /* Scan if needed to meet our targets. */
                if (pma != NULL ||