feat: logger: decrease binary size

When new rate-limiter log macros were added, the binary size increased
by ~150KiB. (mainly the .text section got bigger by ~105KiB)

In order to partially mitigate this move duplicated checking logic into
a `LogRateLimiter` type and mark that function with `inline(never)`

This saves ~70KiB of .text section space.

Signed-off-by: Egor Lazarchuk <yegorlz@amazon.co.uk>

Author: ShadowCurse

src/vmm/src/logger/mod.rs

@@ -108,23 +108,8 @@ macro_rules! __log_rate_limited_impl {
                     $crate::logger::rate_limited::DEFAULT_BURST,
                     $crate::logger::rate_limited::DEFAULT_REFILL_TIME_MS,
                 );
-            static SUPPRESSED: std::sync::atomic::AtomicU64 =
-                std::sync::atomic::AtomicU64::new(0);
-
-            if LIMITER.check() {
-                let suppressed =
-                    SUPPRESSED.swap(0, std::sync::atomic::Ordering::Relaxed);
-                if suppressed > 0 {
-                    $crate::warn_unrestricted!(
-                        "{suppressed} messages were suppressed due to rate limiting"
-                    );
-                }
+            if LIMITER.check_maybe_suppressed() {
                 $level_macro!($($arg)+);
-            } else {
-                SUPPRESSED.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
-                $crate::logger::IncMetric::inc(
-                    &$crate::logger::METRICS.logger.rate_limited_log_count,
-                );
             }
         }
     }};

src/vmm/src/logger/rate_limited.rs

@@ -6,8 +6,10 @@
 //! `LogRateLimiter` instance via a `static`, so flooding one callsite does
 //! not suppress unrelated log messages.
 
+use std::sync::atomic::{AtomicU64, Ordering};
 use std::sync::{Mutex, OnceLock};
 
+use crate::logger::{IncMetric, METRICS};
 use crate::rate_limiter::TokenBucket;
 
 /// Maximum number of messages allowed per refill period.
@@ -25,6 +27,7 @@ pub struct LogRateLimiter {
     inner: OnceLock<Mutex<TokenBucket>>,
     burst: u64,
     refill_time_ms: u64,
+    suppressed: AtomicU64,
 }
 
 impl Default for LogRateLimiter {
@@ -44,6 +47,7 @@ impl LogRateLimiter {
             inner: OnceLock::new(),
             burst,
             refill_time_ms,
+            suppressed: AtomicU64::new(0),
         }
     }
 
@@ -64,6 +68,26 @@ impl LogRateLimiter {
             crate::rate_limiter::BucketReduction::Success
         )
     }
+
+    /// Check if log is should be emitted and print a warning if it was
+    /// suppressed before. Marked to be never inlined since it is called in a
+    /// lot of macros and would blow up the binary size otherwise.
+    #[inline(never)]
+    pub fn check_maybe_suppressed(&self) -> bool {
+        if self.check() {
+            let suppressed = self.suppressed.swap(0, Ordering::Relaxed);
+            if 0 < suppressed {
+                crate::logger::warn_unrestricted!(
+                    "{suppressed} messages were suppressed due to rate limiting"
+                );
+            }
+            true
+        } else {
+            self.suppressed.fetch_add(1, Ordering::Relaxed);
+            METRICS.logger.rate_limited_log_count.inc();
+            false
+        }
+    }
 }
 
 #[cfg(test)]