[https://nvbugs/5404000][fix] Ensure consistency between firstTokenTime and lastTokenTime (NVIDIA#8294)

achartier · dominicshanshan · commit 963ad46d5c69 · 2025-11-02T23:10:36.000-08:00
Signed-off-by: Aurelien Chartier &lt;2567591+achartier@users.noreply.github.com&gt;
diff --git a/cpp/include/tensorrt_llm/batch_manager/llmRequest.h b/cpp/include/tensorrt_llm/batch_manager/llmRequest.h
@@ -1828,9 +1828,10 @@ class GenericLlmRequest
 
     void updatePerfMetrics(executor::IterationType iter)
     {
+        auto const currentTokenTime = getSteadyClockNow();
+
         if (!mPerfMetrics.firstIter)
         {
-            auto const currentTokenTime = getSteadyClockNow();
             mPerfMetrics.firstIter = iter;
             mPerfMetrics.timingMetrics.firstTokenTime = currentTokenTime;
         }
@@ -1839,7 +1840,6 @@ class GenericLlmRequest
 
         if (isFinished())
         {
-            auto const currentTokenTime = getSteadyClockNow();
             mPerfMetrics.lastIter = iter;
             mPerfMetrics.timingMetrics.lastTokenTime = currentTokenTime;
         }

Original file line number	Diff line number	Diff line change
`@@ -1828,9 +1828,10 @@ class GenericLlmRequest`
`1828`	`1828`
`1829`	`1829`	`void updatePerfMetrics(executor::IterationType iter)`
`1830`	`1830`	`{`
	`1831`	`+ auto const currentTokenTime = getSteadyClockNow();`
	`1832`	`+`
`1831`	`1833`	`if (!mPerfMetrics.firstIter)`
`1832`	`1834`	`{`
`1833`		`- auto const currentTokenTime = getSteadyClockNow();`
`1834`	`1835`	`mPerfMetrics.firstIter = iter;`
`1835`	`1836`	`mPerfMetrics.timingMetrics.firstTokenTime = currentTokenTime;`
`1836`	`1837`	`}`
`@@ -1839,7 +1840,6 @@ class GenericLlmRequest`
`1839`	`1840`
`1840`	`1841`	`if (isFinished())`
`1841`	`1842`	`{`
`1842`		`- auto const currentTokenTime = getSteadyClockNow();`
`1843`	`1843`	`mPerfMetrics.lastIter = iter;`
`1844`	`1844`	`mPerfMetrics.timingMetrics.lastTokenTime = currentTokenTime;`
`1845`	`1845`	`}`