From owner-svn-src-all@FreeBSD.ORG Tue Jun 3 01:52:05 2014 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id C0804B17; Tue, 3 Jun 2014 01:52:05 +0000 (UTC) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 9FB1C2C01; Tue, 3 Jun 2014 01:52:05 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.8/8.14.8) with ESMTP id s531q5aM055956; Tue, 3 Jun 2014 01:52:05 GMT (envelope-from markj@svn.freebsd.org) Received: (from markj@localhost) by svn.freebsd.org (8.14.8/8.14.8/Submit) id s531q5vf055955; Tue, 3 Jun 2014 01:52:05 GMT (envelope-from markj@svn.freebsd.org) Message-Id: <201406030152.s531q5vf055955@svn.freebsd.org> From: Mark Johnston Date: Tue, 3 Jun 2014 01:52:05 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-vendor@freebsd.org Subject: svn commit: r266993 - vendor-sys/illumos/dist/uts/common/dtrace X-SVN-Group: vendor-sys MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Jun 2014 01:52:05 -0000 Author: markj Date: Tue Jun 3 01:52:05 2014 New Revision: 266993 URL: http://svnweb.freebsd.org/changeset/base/266993 Log: 4469 DTrace helper tracing should be dynamic illumos/illumos-gate@902686d13f8a39cfdc57f5605470369eafa51e1f Modified: vendor-sys/illumos/dist/uts/common/dtrace/dtrace.c Modified: vendor-sys/illumos/dist/uts/common/dtrace/dtrace.c ============================================================================== --- vendor-sys/illumos/dist/uts/common/dtrace/dtrace.c Tue Jun 3 01:42:09 2014 (r266992) +++ vendor-sys/illumos/dist/uts/common/dtrace/dtrace.c Tue Jun 3 01:52:05 2014 (r266993) @@ -269,17 +269,22 @@ dtrace_id_t dtrace_probeid_error; /* sp /* * DTrace Helper Tracing Variables - */ -uint32_t dtrace_helptrace_next = 0; -uint32_t dtrace_helptrace_nlocals; -char *dtrace_helptrace_buffer; -int dtrace_helptrace_bufsize = 512 * 1024; - -#ifdef DEBUG -int dtrace_helptrace_enabled = 1; -#else -int dtrace_helptrace_enabled = 0; -#endif + * + * These variables should be set dynamically to enable helper tracing. The + * only variables that should be set are dtrace_helptrace_enable (which should + * be set to a non-zero value to allocate helper tracing buffers on the next + * open of /dev/dtrace) and dtrace_helptrace_disable (which should be set to a + * non-zero value to deallocate helper tracing buffers on the next close of + * /dev/dtrace). When (and only when) helper tracing is disabled, the + * buffer size may also be set via dtrace_helptrace_bufsize. + */ +int dtrace_helptrace_enable = 0; +int dtrace_helptrace_disable = 0; +int dtrace_helptrace_bufsize = 16 * 1024 * 1024; +uint32_t dtrace_helptrace_nlocals; +static dtrace_helptrace_t *dtrace_helptrace_buffer; +static uint32_t dtrace_helptrace_next = 0; +static int dtrace_helptrace_wrapped = 0; /* * DTrace Error Hashing @@ -14321,10 +14326,10 @@ dtrace_helper_trace(dtrace_helper_action dtrace_mstate_t *mstate, dtrace_vstate_t *vstate, int where) { uint32_t size, next, nnext, i; - dtrace_helptrace_t *ent; + dtrace_helptrace_t *ent, *buffer; uint16_t flags = cpu_core[CPU->cpu_id].cpuc_dtrace_flags; - if (!dtrace_helptrace_enabled) + if ((buffer = dtrace_helptrace_buffer) == NULL) return; ASSERT(vstate->dtvs_nlocals <= dtrace_helptrace_nlocals); @@ -14352,10 +14357,12 @@ dtrace_helper_trace(dtrace_helper_action /* * We have our slot; fill it in. */ - if (nnext == size) + if (nnext == size) { + dtrace_helptrace_wrapped++; next = 0; + } - ent = (dtrace_helptrace_t *)&dtrace_helptrace_buffer[next]; + ent = (dtrace_helptrace_t *)((uintptr_t)buffer + next); ent->dtht_helper = helper; ent->dtht_where = where; ent->dtht_nlocals = vstate->dtvs_nlocals; @@ -14389,7 +14396,7 @@ dtrace_helper(int which, dtrace_mstate_t dtrace_helper_action_t *helper; dtrace_vstate_t *vstate; dtrace_difo_t *pred; - int i, trace = dtrace_helptrace_enabled; + int i, trace = dtrace_helptrace_buffer != NULL; ASSERT(which >= 0 && which < DTRACE_NHELPER_ACTIONS); @@ -15706,17 +15713,6 @@ dtrace_attach(dev_info_t *devi, ddi_atta mutex_exit(&cpu_lock); /* - * If DTrace helper tracing is enabled, we need to allocate the - * trace buffer and initialize the values. - */ - if (dtrace_helptrace_enabled) { - ASSERT(dtrace_helptrace_buffer == NULL); - dtrace_helptrace_buffer = - kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP); - dtrace_helptrace_next = 0; - } - - /* * If there are already providers, we must ask them to provide their * probes, and then match any anonymous enabling against them. Note * that there should be no other retained enablings at this time: @@ -15812,6 +15808,18 @@ dtrace_open(dev_t *devp, int flag, int o return (EBUSY); } + if (dtrace_helptrace_enable && dtrace_helptrace_buffer == NULL) { + /* + * If DTrace helper tracing is enabled, we need to allocate the + * trace buffer and initialize the values. + */ + dtrace_helptrace_buffer = + kmem_zalloc(dtrace_helptrace_bufsize, KM_SLEEP); + dtrace_helptrace_next = 0; + dtrace_helptrace_wrapped = 0; + dtrace_helptrace_enable = 0; + } + state = dtrace_state_create(devp, cred_p); mutex_exit(&cpu_lock); @@ -15833,6 +15841,7 @@ dtrace_close(dev_t dev, int flag, int ot { minor_t minor = getminor(dev); dtrace_state_t *state; + dtrace_helptrace_t *buf = NULL; if (minor == DTRACEMNRN_HELPER) return (0); @@ -15850,6 +15859,18 @@ dtrace_close(dev_t dev, int flag, int ot dtrace_state_destroy(state->dts_anon); } + if (dtrace_helptrace_disable) { + /* + * If we have been told to disable helper tracing, set the + * buffer to NULL before calling into dtrace_state_destroy(); + * we take advantage of its dtrace_sync() to know that no + * CPU is in probe context with enabled helper tracing + * after it returns. + */ + buf = dtrace_helptrace_buffer; + dtrace_helptrace_buffer = NULL; + } + dtrace_state_destroy(state); ASSERT(dtrace_opens > 0); @@ -15860,6 +15881,11 @@ dtrace_close(dev_t dev, int flag, int ot if (--dtrace_opens == 0 && dtrace_anon.dta_enabling == NULL) (void) kdi_dtrace_set(KDI_DTSET_DTRACE_DEACTIVATE); + if (buf != NULL) { + kmem_free(buf, dtrace_helptrace_bufsize); + dtrace_helptrace_disable = 0; + } + mutex_exit(&dtrace_lock); mutex_exit(&cpu_lock); @@ -16753,11 +16779,6 @@ dtrace_detach(dev_info_t *dip, ddi_detac mutex_exit(&cpu_lock); - if (dtrace_helptrace_enabled) { - kmem_free(dtrace_helptrace_buffer, dtrace_helptrace_bufsize); - dtrace_helptrace_buffer = NULL; - } - kmem_free(dtrace_probes, dtrace_nprobes * sizeof (dtrace_probe_t *)); dtrace_probes = NULL; dtrace_nprobes = 0;