Date: Sun, 3 Jun 2012 16:06:56 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r236516 - head/sys/kern Message-ID: <201206031606.q53G6ug2070704@svn.freebsd.org>
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Author: kib Date: Sun Jun 3 16:06:56 2012 New Revision: 236516 URL: http://svn.freebsd.org/changeset/base/236516 Log: Count and export the number of prefaulting happen. MFC after: 1 month Modified: head/sys/kern/vfs_vnops.c Modified: head/sys/kern/vfs_vnops.c ============================================================================== --- head/sys/kern/vfs_vnops.c Sun Jun 3 14:54:50 2012 (r236515) +++ head/sys/kern/vfs_vnops.c Sun Jun 3 16:06:56 2012 (r236516) @@ -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 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;
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