[src/trunk]: src/sys/uvm Add uao_set_pgfl to limit a uvm_aobj's pages to a sp...

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

details:   https://anonhg.NetBSD.org/src/rev/e0fd0cba6c89
branches:  trunk
changeset: 329383:e0fd0cba6c89
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Thu May 22 14:01:46 2014 +0000

description:
Add uao_set_pgfl to limit a uvm_aobj's pages to a specified freelist.

Brought up on tech-kern:

https://mail-index.netbsd.org/tech-kern/2014/05/20/msg017095.html

diffstat:

 sys/uvm/uvm_aobj.c   |  53 ++++++++++++++++++++++++++++++++++++++++++++++-----
 sys/uvm/uvm_extern.h |   3 +-
 2 files changed, 49 insertions(+), 7 deletions(-)

diffs (126 lines):

diff -r fe9b72222a85 -r e0fd0cba6c89 sys/uvm/uvm_aobj.c
--- a/sys/uvm/uvm_aobj.c        Thu May 22 13:35:45 2014 +0000
+++ b/sys/uvm/uvm_aobj.c        Thu May 22 14:01:46 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_aobj.c,v 1.120 2013/10/25 20:22:55 martin Exp $    */
+/*     $NetBSD: uvm_aobj.c,v 1.121 2014/05/22 14:01:46 riastradh Exp $ */
 
 /*
  * Copyright (c) 1998 Chuck Silvers, Charles D. Cranor and
@@ -38,7 +38,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: uvm_aobj.c,v 1.120 2013/10/25 20:22:55 martin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: uvm_aobj.c,v 1.121 2014/05/22 14:01:46 riastradh Exp $");
 
 #include "opt_uvmhist.h"
 
@@ -146,6 +146,7 @@
        struct uao_swhash *u_swhash;
        u_long u_swhashmask;            /* mask for hashtable */
        LIST_ENTRY(uvm_aobj) u_list;    /* global list of aobjs */
+       int u_freelist;           /* freelist to allocate pages from */
 };
 
 static void    uao_free(struct uvm_aobj *);
@@ -161,6 +162,8 @@
 static bool uao_pagein_page(struct uvm_aobj *, int);
 #endif /* defined(VMSWAP) */
 
+static struct vm_page  *uao_pagealloc(struct uvm_object *, voff_t, int);
+
 /*
  * aobj_pager
  *
@@ -436,6 +439,12 @@
        }
 
        /*
+        * no freelist by default
+        */
+
+       aobj->u_freelist = VM_NFREELIST;
+
+       /*
         * allocate hash/array if necessary
         *
         * note: in the KERNSWAP case no need to worry about locking since
@@ -490,6 +499,39 @@
 }
 
 /*
+ * uao_set_pgfl: allocate pages only from the specified freelist.
+ *
+ * => must be called before any pages are allocated for the object.
+ */
+
+void
+uao_set_pgfl(struct uvm_object *uobj, int freelist)
+{
+       struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
+
+       KASSERTMSG((0 <= freelist), "invalid freelist %d", freelist);
+       KASSERTMSG((freelist < VM_NFREELIST), "invalid freelist %d", freelist);
+
+       aobj->u_freelist = freelist;
+}
+
+/*
+ * uao_pagealloc: allocate a page for aobj.
+ */
+
+static inline struct vm_page *
+uao_pagealloc(struct uvm_object *uobj, voff_t offset, int flags)
+{
+       struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
+
+       if (__predict_true(aobj->u_freelist == VM_NFREELIST))
+               return uvm_pagealloc(uobj, offset, NULL, flags);
+       else
+               return uvm_pagealloc_strat(uobj, offset, NULL, flags,
+                   UVM_PGA_STRAT_ONLY, aobj->u_freelist);
+}
+
+/*
  * uao_init: set up aobj pager subsystem
  *
  * => called at boot time from uvm_pager_init()
@@ -864,8 +906,8 @@
 
                        if (ptmp == NULL && uao_find_swslot(uobj,
                            current_offset >> PAGE_SHIFT) == 0) {
-                               ptmp = uvm_pagealloc(uobj, current_offset,
-                                   NULL, UVM_FLAG_COLORMATCH|UVM_PGA_ZERO);
+                               ptmp = uao_pagealloc(uobj, current_offset,
+                                   UVM_FLAG_COLORMATCH|UVM_PGA_ZERO);
                                if (ptmp) {
                                        /* new page */
                                        ptmp->flags &= ~(PG_FAKE);
@@ -959,8 +1001,7 @@
                        /* not resident?   allocate one now (if we can) */
                        if (ptmp == NULL) {
 
-                               ptmp = uvm_pagealloc(uobj, current_offset,
-                                   NULL, 0);
+                               ptmp = uao_pagealloc(uobj, current_offset, 0);
 
                                /* out of RAM? */
                                if (ptmp == NULL) {
diff -r fe9b72222a85 -r e0fd0cba6c89 sys/uvm/uvm_extern.h
--- a/sys/uvm/uvm_extern.h      Thu May 22 13:35:45 2014 +0000
+++ b/sys/uvm/uvm_extern.h      Thu May 22 14:01:46 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: uvm_extern.h,v 1.189 2014/02/21 22:08:07 skrll Exp $   */
+/*     $NetBSD: uvm_extern.h,v 1.190 2014/05/22 14:01:46 riastradh Exp $       */
 
 /*
  * Copyright (c) 1997 Charles D. Cranor and Washington University.
@@ -539,6 +539,7 @@
 
 /* uvm_aobj.c */
 struct uvm_object      *uao_create(vsize_t, int);
+void                   uao_set_pgfl(struct uvm_object *, int);
 void                   uao_detach(struct uvm_object *);
 void                   uao_reference(struct uvm_object *);