Improve ELF symbolization performance

CHANGELOG.md

@@ -2,6 +2,7 @@ Unreleased
 ----------
 - Added support for relocatable ELF and DWARF
 - Added support for kernel module symbolization with DWARF data
+- Improved performance of ELF symbolization
 - Bumped minimum supported Rust version to `1.88`
 
 

src/elf/parser.rs

@@ -373,18 +373,19 @@ impl<'elf> SymbolTableCache<'elf> {
     }
 
     fn create_by_addr_idx(&self) -> Box<[usize]> {
-        let mut by_addr_idx = self
-            .syms
-            .iter(0)
-            .enumerate()
-            // Filter out any symbols that we do not support.
-            .filter(|(_idx, sym)| sym.matches(SymType::Undefined))
-            .map(|(idx, _sym)| idx)
-            .collect::<Box<[_]>>();
+        let mut by_addr_idx = Vec::with_capacity(self.syms.len());
+        let () = by_addr_idx.extend(
+            self.syms
+                .iter(0)
+                .enumerate()
+                // Filter out any symbols that we do not support.
+                .filter(|(_idx, sym)| sym.matches(SymType::Undefined))
+                .map(|(idx, _sym)| idx),
+        );
 
         // Order symbols by address and those with equal address descending by
         // size.
-        let () = by_addr_idx.sort_by(|idx1, idx2| {
+        let () = by_addr_idx.sort_unstable_by(|idx1, idx2| {
             // SANITY: Both indexes originate in our code and are known
             //         to be in bounds.
             let sym1 = self.syms.get(*idx1).unwrap();
@@ -394,7 +395,7 @@ impl<'elf> SymbolTableCache<'elf> {
                 .then_with(|| sym1.size().cmp(&sym2.size()).reverse())
         });
 
-        by_addr_idx
+        by_addr_idx.into_boxed_slice()
     }
 
     fn ensure_by_addr_idx(&self) -> &[usize] {
@@ -431,7 +432,7 @@ impl<'elf> SymbolTableCache<'elf> {
             })
             .collect::<Result<Box<[_]>>>()?;
 
-        let () = str2sym.sort_by_key(|(name, _i)| name.bytes(&self.strs));
+        let () = str2sym.sort_unstable_by_key(|(name, _i)| name.bytes(&self.strs));
         Ok(str2sym)
     }