Changeset 89763 in vbox

Timestamp:

Jun 17, 2021 9:40:24 AM (3 years ago)

Author:

vboxsync

Message:

VMM/DBGFR3SampleReport: Remove Windows specific changes and change the way how the sampling is started from the timer callback to avoid possible deadlocks between the timer callback and the EMTs doing the sampling

File:

• trunk/src/VBox/VMM/VMMR3/DBGFR3SampleReport.cpp (modified) (8 diffs)

trunk/src/VBox/VMM/VMMR3/DBGFR3SampleReport.cpp

@@ -135 +135 @@
     /** The report created after sampling was stopped. */
     char                             *pszReport;
+    /** Number of EMTs having a guest sample operation queued. */
+    volatile uint32_t                cEmtsActive;
     /** Array of per VCPU samples collected. */
     DBGFSAMPLEREPORTVCPU             aCpus[1];
@@ -377 +379 @@
  * each VCPU.
  *
- * @returns Strict VBox status code.
- * @param   pVM                     The VM instance data.
- * @param   pVCpu                   The virtual CPU we execute on.
- * @param   pvUser                  Opaque user data.
- */
-static DECLCALLBACK(VBOXSTRICTRC) dbgfR3SampleReportSample(PVM pVM, PVMCPU pVCpu, void *pvUser)
-{
-    RT_NOREF(pVM);
-    PDBGFSAMPLEREPORTINT pThis = (PDBGFSAMPLEREPORTINT)pvUser;
+ * @returns nothing.
+ * @param   pThis                    Pointer to the sample report instance.
+ */
+static DECLCALLBACK(void) dbgfR3SampleReportSample(PDBGFSAMPLEREPORTINT pThis)
+{
+    PVM pVM = pThis->pUVM->pVM;
+    PVMCPU pVCpu = VMMGetCpu(pVM);
 
     PCDBGFSTACKFRAME pFrameFirst;
@@ -437 +437 @@
         LogRelMax(10, ("Sampling guest stack on VCPU %u failed with rc=%Rrc\n", pVCpu->idCpu, rc));
 
-    if (pVCpu->idCpu == 0)
-    {
-        /* Destroy the timer if requested. */
-        if (ASMAtomicReadU32((volatile uint32_t *)&pThis->enmState) == DBGFSAMPLEREPORTSTATE_STOPPING)
-        {
-#ifndef RT_OS_WINDOWS
-            rc = RTTimerStop(pThis->hTimer); AssertRC(rc); RT_NOREF(rc);
-#endif
-            rc = RTTimerDestroy(pThis->hTimer); AssertRC(rc); RT_NOREF(rc);
-            pThis->hTimer = NULL;
-
-            DBGFSAMPLEREPORTINFOHLP Hlp;
-            PCDBGFINFOHLP           pHlp = &Hlp.Core;
-
-            dbgfR3SampleReportInfoHlpInit(&Hlp);
-
-            /* Some early dump code. */
-            for (uint32_t i = 0; i < pThis->pUVM->cCpus; i++)
-            {
-                PCDBGFSAMPLEREPORTVCPU pSampleVCpu = &pThis->aCpus[i];
-
-                pHlp->pfnPrintf(pHlp, "Sample report for vCPU %u:\n", i);
-                dbgfR3SampleReportDumpFrame(pHlp, pThis->pUVM, &pSampleVCpu->FrameRoot, 0);
-            }
-
-            /* Shameless copy from VMMGuruMeditation.cpp */
-            static struct
-            {
-                const char *pszInfo;
-                const char *pszArgs;
-            } const     aInfo[] =
-            {
-                { "mappings",        NULL },
-                { "mode",            "all" },
-                { "handlers",        "phys virt hyper stats" },
-                { "timers",          NULL },
-                { "activetimers",    NULL },
-            };
-            for (unsigned i = 0; i < RT_ELEMENTS(aInfo); i++)
-            {
-                pHlp->pfnPrintf(pHlp,
-                                "!!\n"
-                                "!! {%s, %s}\n"
-                                "!!\n",
-                                aInfo[i].pszInfo, aInfo[i].pszArgs);
-                DBGFR3Info(pVM->pUVM, aInfo[i].pszInfo, aInfo[i].pszArgs, pHlp);
-            }
-
-            /* All other info items */
-            DBGFR3InfoMulti(pVM,
-                            "*",
-                            "mappings|hma|cpum|cpumguest|cpumguesthwvirt|cpumguestinstr|cpumhyper|cpumhost|cpumvmxfeat|mode|cpuid"
-                            "|pgmpd|pgmcr3|timers|activetimers|handlers|help|cfgm",
+    /* Last EMT finishes the report when sampling was stopped. */
+    uint32_t cEmtsActive = ASMAtomicDecU32(&pThis->cEmtsActive);
+    if (   ASMAtomicReadU32((volatile uint32_t *)&pThis->enmState) == DBGFSAMPLEREPORTSTATE_STOPPING
+        && !cEmtsActive)
+    {
+        rc = RTTimerDestroy(pThis->hTimer); AssertRC(rc); RT_NOREF(rc);
+        pThis->hTimer = NULL;
+
+        DBGFSAMPLEREPORTINFOHLP Hlp;
+        PCDBGFINFOHLP           pHlp = &Hlp.Core;
+
+        dbgfR3SampleReportInfoHlpInit(&Hlp);
+
+        /* Some early dump code. */
+        for (uint32_t i = 0; i < pThis->pUVM->cCpus; i++)
+        {
+            PCDBGFSAMPLEREPORTVCPU pSampleVCpu = &pThis->aCpus[i];
+
+            pHlp->pfnPrintf(pHlp, "Sample report for vCPU %u:\n", i);
+            dbgfR3SampleReportDumpFrame(pHlp, pThis->pUVM, &pSampleVCpu->FrameRoot, 0);
+        }
+
+        /* Shameless copy from VMMGuruMeditation.cpp */
+        static struct
+        {
+            const char *pszInfo;
+            const char *pszArgs;
+        } const     aInfo[] =
+        {
+            { "mappings",        NULL },
+            { "mode",            "all" },
+            { "handlers",        "phys virt hyper stats" },
+            { "timers",          NULL },
+            { "activetimers",    NULL },
+        };
+        for (unsigned i = 0; i < RT_ELEMENTS(aInfo); i++)
+        {
+            pHlp->pfnPrintf(pHlp,
                             "!!\n"
-                            "!! {%s}\n"
+                            "!! {%s, %s}\n"
                             "!!\n",
-                            pHlp);
-
-
-            /* done */
-            pHlp->pfnPrintf(pHlp,
-                            "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n");
-
-            if (pThis->pszReport)
-                RTMemFree(pThis->pszReport);
-            pThis->pszReport = Hlp.pachBuf;
-            Hlp.pachBuf = NULL;
-            dbgfR3SampleReportInfoHlpDelete(&Hlp);
-
-            ASMAtomicXchgU32((volatile uint32_t *)&pThis->enmState, DBGFSAMPLEREPORTSTATE_READY);
-
-            if (pThis->pfnProgress)
-            {
-                pThis->pfnProgress(pThis->pvProgressUser, 100);
-                pThis->pfnProgress    = NULL;
-                pThis->pvProgressUser = NULL;
-            }
-
-            DBGFR3SampleReportRelease(pThis);
-        }
-    }
-
-    return VINF_SUCCESS;
+                            aInfo[i].pszInfo, aInfo[i].pszArgs);
+            DBGFR3Info(pVM->pUVM, aInfo[i].pszInfo, aInfo[i].pszArgs, pHlp);
+        }
+
+        /* All other info items */
+        DBGFR3InfoMulti(pVM,
+                        "*",
+                        "mappings|hma|cpum|cpumguest|cpumguesthwvirt|cpumguestinstr|cpumhyper|cpumhost|cpumvmxfeat|mode|cpuid"
+                        "|pgmpd|pgmcr3|timers|activetimers|handlers|help|cfgm",
+                        "!!\n"
+                        "!! {%s}\n"
+                        "!!\n",
+                        pHlp);
+
+
+        /* done */
+        pHlp->pfnPrintf(pHlp,
+                        "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!\n");
+
+        if (pThis->pszReport)
+            RTMemFree(pThis->pszReport);
+        pThis->pszReport = Hlp.pachBuf;
+        Hlp.pachBuf = NULL;
+        dbgfR3SampleReportInfoHlpDelete(&Hlp);
+
+        ASMAtomicXchgU32((volatile uint32_t *)&pThis->enmState, DBGFSAMPLEREPORTSTATE_READY);
+
+        if (pThis->pfnProgress)
+        {
+            pThis->pfnProgress(pThis->pvProgressUser, 100);
+            pThis->pfnProgress    = NULL;
+            pThis->pvProgressUser = NULL;
+        }
+
+        DBGFR3SampleReportRelease(pThis);
+    }
 }
 
@@ -528 +522 @@
 static DECLCALLBACK(void) dbgfR3SampleReportTakeSample(PRTTIMER pTimer, void *pvUser, uint64_t iTick)
 {
-    RT_NOREF(pTimer);
     PDBGFSAMPLEREPORTINT pThis = (PDBGFSAMPLEREPORTINT)pvUser;
 
@@ -549 +542 @@
             ASMAtomicCmpXchgU32((volatile uint32_t *)&pThis->enmState, DBGFSAMPLEREPORTSTATE_STOPPING,
                                 DBGFSAMPLEREPORTSTATE_RUNNING);
-        }
-    }
-
-    int rc = VMMR3EmtRendezvous(pThis->pUVM->pVM, VMMEMTRENDEZVOUS_FLAGS_TYPE_DESCENDING,
-                                dbgfR3SampleReportSample, pThis);
-    AssertRC(rc); RT_NOREF(rc);
+
+            rc = RTTimerStop(pTimer); AssertRC(rc); RT_NOREF(rc);
+        }
+    }
+
+    ASMAtomicAddU32(&pThis->cEmtsActive, pThis->pUVM->cCpus);
+
+    for (uint32_t i = 0; i < pThis->pUVM->cCpus; i++)
+    {
+        int rc = VMR3ReqCallVoidNoWait(pThis->pUVM->pVM, i, (PFNRT)dbgfR3SampleReportSample, 1, pThis);
+        AssertRC(rc);
+        if (RT_FAILURE(rc))
+            ASMAtomicDecU32(&pThis->cEmtsActive);
+    }
 }
 
@@ -583 +584 @@
         pThis->cSampleIntervalUs = cSampleIntervalUs;
         pThis->enmState          = DBGFSAMPLEREPORTSTATE_READY;
+        pThis->cEmtsActive       = 0;
 
         for (uint32_t i = 0; i < pUVM->cCpus; i++)
@@ -684 +686 @@
     DBGFR3SampleReportRetain(pThis);
 
-#ifndef RT_OS_WINDOWS
     rc = RTTimerCreateEx(&pThis->hTimer, pThis->cSampleIntervalUs * 1000,
                          RTTIMER_FLAGS_CPU_ANY | RTTIMER_FLAGS_HIGH_RES,
@@ -690 +691 @@
     if (RT_SUCCESS(rc))
         rc = RTTimerStart(pThis->hTimer, 0 /*u64First*/);
-#else
-    rc = RTTimerCreate(&pThis->hTimer, pThis->cSampleIntervalUs / 1000,
-                       dbgfR3SampleReportTakeSample, pThis);
-#endif
-
     if (RT_FAILURE(rc))
     {