From c4e9a0db383715bae8f670ce24cab62ac9bc85a6 Mon Sep 17 00:00:00 2001
From: Yuke Peng <pykfirst@gmail.com>
Date: Fri, 9 Aug 2024 12:49:27 +0800
Subject: [PATCH] Remove the implementation of `MADV_DONTNEED`

---
 kernel/aster-nix/src/syscall/madvise.rs | 15 +++------------
 1 file changed, 3 insertions(+), 12 deletions(-)

diff --git a/kernel/aster-nix/src/syscall/madvise.rs b/kernel/aster-nix/src/syscall/madvise.rs
index 8254a1e95..28666a00b 100644
--- a/kernel/aster-nix/src/syscall/madvise.rs
+++ b/kernel/aster-nix/src/syscall/madvise.rs
@@ -17,23 +17,14 @@ pub fn sys_madvise(start: Vaddr, len: usize, behavior: i32) -> Result<SyscallRet
             let mut buffer = vec![0u8; len];
             read_bytes_from_user(start, &mut VmWriter::from(buffer.as_mut_slice()))?;
         }
-        MadviseBehavior::MADV_DONTNEED => madv_dontneed(start, len)?,
+        MadviseBehavior::MADV_DONTNEED => {
+            warn!("MADV_DONTNEED isn't implemented, do nothing for now.");
+        }
         _ => todo!(),
     }
     Ok(SyscallReturn::Return(0))
 }
 
-fn madv_dontneed(start: Vaddr, len: usize) -> Result<()> {
-    debug_assert!(start % PAGE_SIZE == 0);
-    debug_assert!(len % PAGE_SIZE == 0);
-    let current = current!();
-    let root_vmar = current.root_vmar();
-    let advised_range = start..start + len;
-    // `destroy()` interface may require adjustment and replacement afterwards.
-    let _ = root_vmar.destroy(advised_range);
-    Ok(())
-}
-
 #[repr(i32)]
 #[derive(Debug, Clone, Copy, TryFromInt)]
 #[allow(non_camel_case_types)]