Re: [PATCH] fix nvidia slowdowns and fix memleak in vm_map.c

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

    All right, I looked it over.  If I understand the issue correctly
    is it that multiple parallel mappings of the same device was resulting
    in the memory leak?

    I committed a slightly cleaned up (functionally the same) version of
    the patch into DFly though I'm not sure how to test it.  With X I 
    guess.

					-Matt
					Matthew Dillon 
					<dillon@xxxxxxxxxxxxx>


:Hash: SHA1
:
:(patches against sys/vm attached)
:
:Discussion:
:
:(From Christian Zander @ NVIDIA)
:
:> The vm_map.c change just fixes a "hack" introduced in FreeBSD 4.7 to
:> make it possible to use mmap(2) to map kernel memory, specifically to
:> allow invalidation of cached physical addresses. If you could submit
:> this for inclusion in the kernel, that'd be great.
:>=20
:> The device pager leak was found by Tor Egge (of the FreeBSD project)
:> and it was him who suggested the current workaround. I wrote/tested
:> the patch, but you'd have to give him credit (I don't much care about
:> credit as long as it works). I haven't heard back from him for some
:> time, unfortunately, so I'm not sure when either of these patches is
:> going to make its way into the FreeBSD kernel. If you can get a VM
:> person to double-check the change, that'd be great; please CC me and
:> Tor (tor.egge@xxxxxxxxxxxxxxxxxxxx, tegge@xxxxxxxxxxx).
:
:So, if a vm-person (Matt?) could look at this, and mail/CC the people=20
:involved, that would be swell. And don't forget the attribution. :)
:
:Cheers,
:Emiel
:
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:Content-Type: text/x-diff;
:  charset="us-ascii";
:  name="czpatch_vm_fixes.diff"
:Content-Transfer-Encoding: 7bit
:Content-Disposition: attachment;
:	filename="czpatch_vm_fixes.diff"
:
:Index: device_pager.c
:===================================================================
:RCS file: /home/dcvs/src/sys/vm/device_pager.c,v
:retrieving revision 1.7
:diff -u -u -r1.7 device_pager.c
:--- device_pager.c	23 Mar 2004 22:54:32 -0000	1.7
:+++ device_pager.c	20 Jul 2004 22:21:39 -0000
:@@ -70,6 +70,7 @@
: 
: static vm_page_t dev_pager_getfake (vm_paddr_t);
: static void dev_pager_putfake (vm_page_t);
:+static void dev_pager_updatefake (vm_page_t, vm_paddr_t);
: 
: static int dev_pager_alloc_lock, dev_pager_alloc_lock_want;
: 
:@@ -194,18 +195,31 @@
: 
: 	paddr = pmap_phys_address(dev_dmmap(dev, (vm_offset_t) offset << PAGE_SHIFT, prot));
: 	KASSERT(paddr != -1,("dev_pager_getpage: map function returns error"));
:-	/*
:-	 * Replace the passed in reqpage page with our own fake page and free up the
:-	 * all of the original pages.
:-	 */
:-	page = dev_pager_getfake(paddr);
:-	TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
:-	for (i = 0; i < count; i++) {
:-		vm_page_free(m[i]);
:+
:+	if ((m[reqpage]->flags & PG_FICTITIOUS) != 0) {
:+		/*
:+		 * If the passed in reqpage page is a fake page, update it with
:+		 * the new physical address.
:+		 */
:+		dev_pager_updatefake(m[reqpage], paddr);
:+		for (i = 0; i < count; i++) {
:+			if (i != reqpage)
:+				vm_page_free(m[i]);
:+		}
:+	} else {
:+		/*
:+		 * Replace the passed in reqpage page with our own fake page and
:+		 * free up the all of the original pages.
:+		 */
:+		page = dev_pager_getfake(paddr);
:+		TAILQ_INSERT_TAIL(&object->un_pager.devp.devp_pglist, page, pageq);
:+		for (i = 0; i < count; i++) {
:+			vm_page_free(m[i]);
:+		}
:+		s = splhigh();
:+		vm_page_insert(page, object, offset);
:+		splx(s);
: 	}
:-	s = splhigh();
:-	vm_page_insert(page, object, offset);
:-	splx(s);
: 
: 	return (VM_PAGER_OK);
: }
:@@ -256,3 +270,11 @@
: 		panic("dev_pager_putfake: bad page");
: 	zfree(fakepg_zone, m);
: }
:+
:+static void
:+dev_pager_updatefake(vm_page_t m, vm_paddr_t paddr)
:+{
:+	if (!(m->flags & PG_FICTITIOUS))
:+		panic("dev_pager_putfake: bad page");
:+	m->phys_addr = paddr;
:+}
:Index: vm_map.c
:===================================================================
:RCS file: /home/dcvs/src/sys/vm/vm_map.c,v
:retrieving revision 1.28
:diff -u -u -r1.28 vm_map.c
:--- vm_map.c	27 May 2004 00:38:58 -0000	1.28
:+++ vm_map.c	20 Jul 2004 22:21:46 -0000
:@@ -2205,7 +2205,7 @@
: 			vm_object_page_remove(object,
: 			    OFF_TO_IDX(offset),
: 			    OFF_TO_IDX(offset + size + PAGE_MASK),
:-			    TRUE);
:+			    (object->type == OBJT_DEVICE) ? FALSE : TRUE);
: 			vm_object_deallocate(object);
: 		}
: 		start += size;