> From: Mike Belopuhov <m...@belopuhov.com>
> Date: Wed, 30 Apr 2014 16:00:45 +0200
>
> On 30 April 2014 15:55, Mark Kettenis <mark.kette...@xs4all.nl> wrote:
> >> Date: Wed, 30 Apr 2014 15:38:39 +0200 (CEST)
> >> From: Mark Kettenis <mark.kette...@xs4all.nl>
> >>
> >> > Date: Wed, 30 Apr 2014 13:39:20 +0100
> >> > From: Stuart Henderson <st...@openbsd.org>
> >> >
> >> > Seen when running e2fsprogs regression tests with /tmp on tmpfs
> >>
> >> I'm not surprised; tmpfs contains some serious bugs. I recommend not
> >> using it until those are fixed.
> >
> > Which means, I'd like somebody else besides espie@ to comment on my
> > uvm_aobj.c list manipulation hack diff.
> >
>
> Diff made sense to me when I looked at it, but I would rather hide
> direct pointer access :/ Perhaps LIST_SWAP does a tiny bit more,
> but it's cleaner and perhaps can be useful in the future.
I'm not comfortable with introducing more <sys/queue.h> APIs. So
perhaps we should just punt on the optimization and remove/insert all
list items. Removing the trap comments that pedro set up...
Index: uvm_aobj.c
===================================================================
RCS file: /cvs/src/sys/uvm/uvm_aobj.c,v
retrieving revision 1.61
diff -u -p -r1.61 uvm_aobj.c
--- uvm_aobj.c 13 Apr 2014 23:14:15 -0000 1.61
+++ uvm_aobj.c 30 Apr 2014 14:52:33 -0000
@@ -431,6 +431,7 @@ uao_shrink_hash(struct uvm_object *uobj,
{
struct uvm_aobj *aobj = (struct uvm_aobj *)uobj;
struct uao_swhash *new_swhash;
+ struct uao_swhash_elt *elt;
unsigned long new_hashmask;
int i;
@@ -456,8 +457,13 @@ uao_shrink_hash(struct uvm_object *uobj,
* Even though the hash table size is changing, the hash of the buckets
* we are interested in copying should not change.
*/
- for (i = 0; i < UAO_SWHASH_BUCKETS(aobj->u_pages); i++)
- LIST_FIRST(&new_swhash[i]) = LIST_FIRST(&aobj->u_swhash[i]);
+ for (i = 0; i < UAO_SWHASH_BUCKETS(aobj->u_pages); i++) {
+ while (LIST_EMPTY(&aobj->u_swhash[i]) == 0) {
+ elt = LIST_FIRST(&aobj->u_swhash[i]);
+ LIST_REMOVE(elt, list);
+ LIST_INSERT_HEAD(&new_swhash[i], elt, list);
+ }
+ }
free(aobj->u_swhash, M_UVMAOBJ);
@@ -609,7 +615,6 @@ uao_grow_hash(struct uvm_object *uobj, i
return ENOMEM;
for (i = 0; i < UAO_SWHASH_BUCKETS(aobj->u_pages); i++) {
- /* XXX pedro: shouldn't copying the list pointers be enough? */
while (LIST_EMPTY(&aobj->u_swhash[i]) == 0) {
elt = LIST_FIRST(&aobj->u_swhash[i]);
LIST_REMOVE(elt, list);
