Date: Sat, 31 Jan 2015 09:07:23 -0600 From: Eric Badger <eric@badgerio.us> To: freebsd-current@freebsd.org Subject: Filepaths in VM map for tmpfs files Message-ID: <54CCEFAB.9040406@badgerio.us>
next in thread | raw e-mail | index | archive | help
This is a multi-part message in MIME format.
--------------010102060709010900020003
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
In FreeBSD 9, examining the VM map of a process (with e.g. 'procstat
-v') with a tmpfs file mapped showed a VNODE type and displayed the file
path. In 10.0 up to CURRENT (I believe this started at r250030), instead
SWAP is shown without a filepath.
This has some unfortunate consequences; I discovered this problem when
trying to use dtrace's pid provider, which fails to find symbols for
executables running from tmpfs.
I've attached a patch which will repair procstat/dtrace. There are a few
other places such a patch would be needed. I'm willing to put together
such a patch, but would like to first hear some feedback that this seems
like a reasonable approach, or if there's anything I've missed.
Thoughts?
Eric
--------------010102060709010900020003
Content-Type: text/x-patch;
name="tmpfs_vnode.diff"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
filename="tmpfs_vnode.diff"
Index: sys/kern/kern_proc.c
===================================================================
--- sys/kern/kern_proc.c (revision 277957)
+++ sys/kern/kern_proc.c (working copy)
@@ -2337,6 +2337,11 @@
break;
case OBJT_SWAP:
kve->kve_type = KVME_TYPE_SWAP;
+ if ((lobj->flags & OBJ_TMPFS) != 0)
+ {
+ vp = lobj->un_pager.swp.swp_tmpfs;
+ vref(vp);
+ }
break;
case OBJT_DEVICE:
kve->kve_type = KVME_TYPE_DEVICE;
--------------010102060709010900020003--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?54CCEFAB.9040406>