svn commit: r358363 - head/sys/vm

[Jan Beich]

Mark Johnston <markj at freebsd.org> writes:

> On Sat, Feb 29, 2020 at 09:24:11PM +0100, Emmanuel Vadot wrote:
>
>> 
>>  Hi Jeff,
>> 
>> On Thu, 27 Feb 2020 02:37:27 +0000 (UTC)
>> Jeff Roberson <jeff at FreeBSD.org> wrote:
>> 
>> > Author: jeff
>> > Date: Thu Feb 27 02:37:27 2020
>> > New Revision: 358363
>> > URL: https://svnweb.freebsd.org/changeset/base/358363
>> > 
>> > Log:
>> >   Add unlocked grab* function variants that use lockless radix code to
>> >   lookup pages.  These variants will fall back to their locked counterparts
>> >   if the page is not present.
>> >   
>> >   Discussed with:	kib, markj
>> >   Differential Revision:	https://reviews.freebsd.org/D23449
>> > 
>> > Modified:
>> >   head/sys/vm/vm_page.c
>> >   head/sys/vm/vm_page.h
>> > 
>> 
>>  We're (jbeich@ and me) seeing wired memory leak since this commit.
>>  A simple way to reproduce is to have drm-kmod (either 4.16 or 5.0) and
>> liba-intel-driver/libva-intel-media-driver and start mpv in a loop :
>> 
>>  while mpv --hwdec=vaapi --start=10.0 --end=10.1 /path/to/file ; do
>>  done
>> 
>>  Reverting this commit on one of my test machine shows that this is the
>> culprit.
>>  If you need anymore info/debug let me know.
>> 
>>  Thanks.
>
> Could you give this patch a try?
>
> diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
> index 9d50881ed27e..41e7a5bb3099 100644
> --- a/sys/vm/vm_page.c
> +++ b/sys/vm/vm_page.c
> @@ -4535,7 +4535,8 @@ vm_page_grab_valid(vm_page_t *mp, vm_object_t object, vm_pindex_t pindex, int al
>  	    (VM_ALLOC_NOWAIT | VM_ALLOC_WAITFAIL | VM_ALLOC_ZERO)) == 0,
>  	    ("vm_page_grab_valid: Invalid flags 0x%X", allocflags));
>  	VM_OBJECT_ASSERT_WLOCKED(object);
> -	pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY);
> +	pflags = allocflags & ~(VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY |
> +	    VM_ALLOC_WIRED);
>  	pflags |= VM_ALLOC_WAITFAIL;
>  
>  retrylookup:

I confirm, the patch fixes the issue. After trying to reproduce for a
few minutes Wired doesn't grow several times larger than ARC Total.

  Mem: 1151M Active, 300M Inact, 41M Laundry, 3417M Wired, 57G Free
  ARC: 2020M Total, 861M MFU, 992M MRU, 3512K Anon, 23M Header, 140M Other
       711M Compressed, 1311M Uncompressed, 1.84:1 Ratio