From a1c506fc956cfc347c56c44311669700c0d500ac Mon Sep 17 00:00:00 2001
From: Codex <codex@localhost>
Date: Thu, 1 Oct 2026 22:16:19 +0300
Subject: [PATCH] Profile CUDA host API duration without serializing GPU
 launches

---
 zluda/src/d4r_api_profile.rs | 34 ++++++++++++++++++++++++++++++++++
 zluda/src/lib.rs             |  3 +++
 2 files changed, 37 insertions(+)
 create mode 100644 zluda/src/d4r_api_profile.rs

diff --git a/zluda/src/d4r_api_profile.rs b/zluda/src/d4r_api_profile.rs
new file mode 100644
index 0000000..ef2da1b
--- /dev/null
+++ b/zluda/src/d4r_api_profile.rs
@@ -0,0 +1,34 @@
+//! Host API timings only: no HIP events, stream waits, or altered scheduling.
+use std::{cell::RefCell, collections::BTreeMap, sync::OnceLock, time::Instant};
+
+#[derive(Default)]
+struct Row { calls: u64, total_ms: f64, max_ms: f64 }
+struct Samples { since: Instant, rows: BTreeMap<&'static str, Row> }
+thread_local! {
+    static SAMPLES: RefCell<Samples> = RefCell::new(Samples { since: Instant::now(), rows: BTreeMap::new() });
+}
+pub(crate) struct Call { name: &'static str, start: Instant }
+impl Call {
+    pub(crate) fn begin(name: &'static str) -> Option<Self> {
+        static ENABLED: OnceLock<bool> = OnceLock::new();
+        if !*ENABLED.get_or_init(|| std::env::var_os("D4R_ZLUDA_PROFILE_API").is_some()) { return None; }
+        Some(Self { name, start: Instant::now() })
+    }
+}
+impl Drop for Call {
+    fn drop(&mut self) {
+        let ms = self.start.elapsed().as_secs_f64() * 1000.;
+        SAMPLES.with(|samples| {
+            let mut samples = samples.borrow_mut();
+            let row = samples.rows.entry(self.name).or_default();
+            row.calls += 1; row.total_ms += ms; row.max_ms = row.max_ms.max(ms);
+            let period_ms = samples.since.elapsed().as_secs_f64() * 1000.;
+            if period_ms < 2000. { return; }
+            for (name, row) in &samples.rows {
+                eprintln!("D4R_CUDA_API_PROFILE thread={:?} api={name} calls={} total_ms={:.6} max_ms={:.6} period_ms={period_ms:.6} serializing=0",
+                    std::thread::current().id(), row.calls, row.total_ms, row.max_ms);
+            }
+            samples.rows.clear(); samples.since = Instant::now();
+        });
+    }
+}
diff --git a/zluda/src/lib.rs b/zluda/src/lib.rs
index ecdeb3e..31bfa42 100644
--- a/zluda/src/lib.rs
+++ b/zluda/src/lib.rs
@@ -2,6 +2,7 @@ use cuda_types::cuda::CUerror;
 use std::sync::atomic::{AtomicBool, Ordering};
 
 pub(crate) mod r#impl;
+mod d4r_api_profile;
 #[cfg_attr(windows, path = "os_win.rs")]
 #[cfg_attr(not(windows), path = "os_unix.rs")]
 mod os;
@@ -40,6 +41,7 @@ macro_rules! implemented {
                 if !initialized() {
                     return Err(CUerror::DEINITIALIZED);
                 }
+                let _profile = d4r_api_profile::Call::begin(stringify!($fn_name));
                 cuda_macros::cuda_normalize_fn!( crate::r#impl::$fn_name ) ($(zluda_common::FromCuda::<_, CUerror>::from_cuda(&$arg_id)?),*)?;
                 Ok(())
             }
@@ -57,6 +59,7 @@ macro_rules! implemented_in_function {
                 if !initialized() {
                     return Err(CUerror::DEINITIALIZED);
                 }
+                let _profile = d4r_api_profile::Call::begin(stringify!($fn_name));
                 cuda_macros::cuda_normalize_fn!( crate::r#impl::function::$fn_name ) ($(zluda_common::FromCuda::<_, CUerror>::from_cuda(&$arg_id)?),*)?;
                 Ok(())
             }
-- 
2.55.0.windows.5