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| author | Konstantin Belousov <kib@FreeBSD.org> | 2012-06-03 16:06:56 +0000 |
|---|---|---|
| committer | Konstantin Belousov <kib@FreeBSD.org> | 2012-06-03 16:06:56 +0000 |
| commit | bb2f52a61d6f8ba273060e613e6eda3d7681958c (patch) | |
| tree | 5502fa9881c7282a9f947dec56e5b2cb62026a2b /sys | |
| parent | b82bd838f6aef9f9a1d67a3c521bec93ad43b36b (diff) | |
| download | src-bb2f52a61d6f8ba273060e613e6eda3d7681958c.tar.gz src-bb2f52a61d6f8ba273060e613e6eda3d7681958c.zip | |
Count and export the number of prefaulting happen.
MFC after: 1 month
Notes
Notes:
svn path=/head/; revision=236516
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/vfs_vnops.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c index 06fd2245c340..d5a6bf14b08b 100644 --- a/sys/kern/vfs_vnops.c +++ b/sys/kern/vfs_vnops.c @@ -56,6 +56,7 @@ __FBSDID("$FreeBSD$"); #include <sys/filio.h> #include <sys/resourcevar.h> #include <sys/sx.h> +#include <sys/sysctl.h> #include <sys/ttycom.h> #include <sys/conf.h> #include <sys/syslog.h> @@ -696,6 +697,9 @@ unlock: } static const int io_hold_cnt = 16; +static unsigned long vn_io_faults_cnt; +SYSCTL_LONG(_debug, OID_AUTO, vn_io_faults, CTLFLAG_RD, + &vn_io_faults_cnt, 0, "Count of vn_io_fault lock avoidance triggers"); /* * The vn_io_fault() is a wrapper around vn_read() and vn_write() to @@ -793,6 +797,7 @@ vn_io_fault(struct file *fp, struct uio *uio, struct ucred *active_cred, if (error != EFAULT) goto out; + atomic_add_long(&vn_io_faults_cnt, 1); uio_clone->uio_segflg = UIO_NOCOPY; uiomove(NULL, resid - uio->uio_resid, uio_clone); uio_clone->uio_segflg = uio->uio_segflg; |