Date: Sun, 4 Oct 2015 00:40:13 +0000 (UTC) From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r288644 - head/share/dtrace Message-ID: <201510040040.t940eDou000770@repo.freebsd.org>
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Author: pjd Date: Sun Oct 4 00:40:12 2015 New Revision: 288644 URL: https://svnweb.freebsd.org/changeset/base/288644 Log: Add a little, but very useful script for use with programs that work using an event loop and should sleep only when waiting for events (eg. via kevent(2)). When a program is going to sleep in the kernel, the script will show its name, PID, kernel stack trace and userland stack trace. Sleeping in kevent(2) is ignored as it is expected to be valid. Sample output: # ./blocking lynxd lynxd(15042) is blocking... kernel`_cv_wait_sig+0x124 kernel`seltdwait+0xae kernel`sys_poll+0x3a3 kernel`amd64_syscall+0x343 kernel`0xffffffff806c79ab lynxd`poll+0xa lynxd`pqSocketCheck+0xa2 lynxd`pqWaitTimed+0x29 lynxd`connectDBComplete+0xd7 lynxd`PQsetdbLogin+0x2ec lynxd`db_connect+0x3c lynxd`main+0x198 lynxd`_start+0x16f 0x2 lynxd(1925) is blocking... kernel`_cv_wait+0x125 zfs.ko`zio_wait+0x5b zfs.ko`dmu_buf_hold_array_by_dnode+0x1dc zfs.ko`dmu_read+0xcb zfs.ko`zfs_freebsd_getpages+0x37b kernel`VOP_GETPAGES_APV+0xa7 kernel`vnode_pager_getpages+0x9a kernel`vm_fault_hold+0x885 kernel`vm_fault+0x77 kernel`trap_pfault+0x211 kernel`trap+0x506 kernel`0xffffffff806c76c2 lynxd`EVP_add_cipher+0x13 lynxd`SSL_library_init+0x11 lynxd`main+0x94 lynxd`_start+0x16f 0x2 lynxd(1925) is blocking... kernel`_cv_wait+0x125 zfs.ko`zio_wait+0x5b zfs.ko`dbuf_read+0x791 zfs.ko`dbuf_findbp+0x12f zfs.ko`dbuf_hold_impl+0xa2 zfs.ko`dbuf_hold+0x1b zfs.ko`dmu_buf_hold_array_by_dnode+0x153 zfs.ko`dmu_read_uio+0x66 zfs.ko`zfs_freebsd_read+0x3a3 kernel`VOP_READ_APV+0xa1 kernel`vn_read+0x13a kernel`vn_io_fault+0x10b kernel`dofileread+0x95 kernel`kern_readv+0x68 kernel`sys_read+0x63 kernel`amd64_syscall+0x343 kernel`0xffffffff806c79ab lynxd`_read+0xa lynxd`__srefill+0x122 lynxd`fgets+0x78 lynxd`file_gets+0x1d lynxd`BIO_gets+0x64 lynxd`PEM_read_bio+0xf5 lynxd`PEM_X509_INFO_read_bio+0x90 lynxd`X509_load_cert_crl_file+0x47 lynxd`by_file_ctrl+0x2e lynxd`X509_STORE_load_locations+0x4a lynxd`sslctx_init+0x255 lynxd`main+0x215 lynxd`_start+0x16f 0x2 Requested by: gnn Obtained from: Wheel Systems http://wheelsystems.com Added: head/share/dtrace/blocking (contents, props changed) Modified: head/share/dtrace/Makefile Modified: head/share/dtrace/Makefile ============================================================================== --- head/share/dtrace/Makefile Sat Oct 3 22:38:08 2015 (r288643) +++ head/share/dtrace/Makefile Sun Oct 4 00:40:12 2015 (r288644) @@ -12,7 +12,8 @@ SUBDIR= ${_toolkit} _toolkit= toolkit .endif -SCRIPTS= disklatency \ +SCRIPTS= blocking \ + disklatency \ disklatencycmd \ hotopen \ nfsattrstats \ Added: head/share/dtrace/blocking ============================================================================== --- /dev/null 00:00:00 1970 (empty, because file is newly added) +++ head/share/dtrace/blocking Sun Oct 4 00:40:12 2015 (r288644) @@ -0,0 +1,57 @@ +#!/usr/sbin/dtrace -s +/*- + * Copyright (c) 2015 Pawel Jakub Dawidek <pawel@dawidek.net> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + * + * This little script is for use with programs that use event loop and should + * sleep only when waiting for events (eg. via kevent(2)). When a program is + * going to sleep in the kernel, the script will show its name, PID, kernel + * stack trace and userland stack trace. Sleeping in kevent(2) is ignored. + * + * usage: blocking <execname> + */ + +#pragma D option quiet + +syscall::kevent:entry +/execname == $$1/ +{ + self->inkevent = 1; +} + +fbt::sleepq_add:entry +/!self->inkevent && execname == $$1/ +{ + printf("\n%s(%d) is blocking...\n", execname, pid); + stack(); + ustack(); +} + +syscall::kevent:return +/execname == $$1/ +{ + self->inkevent = 0; +}
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