From ba210848e237ec32562023090bb2a119b59897c0 Mon Sep 17 00:00:00 2001
From: guillaume didier <guillaume.didier@inria.fr>
Date: Wed, 18 Mar 2020 14:30:16 +0100
Subject: [PATCH] cache_utils update

---
 cache_utils/src/calibration.rs |  7 ++----
 cache_utils/src/main.rs        | 43 +++++++++++++++++++++++++++++++---
 2 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/cache_utils/src/calibration.rs b/cache_utils/src/calibration.rs
index 1c5d1ca..41a1893 100644
--- a/cache_utils/src/calibration.rs
+++ b/cache_utils/src/calibration.rs
@@ -139,7 +139,7 @@ pub fn calibrate_access(array: &[u8; 4096]) -> u64 {
 }
 
 const CFLUSH_BUCKET_SIZE: usize = 1;
-const CFLUSH_BUCKET_NUMBER: usize = 250;
+const CFLUSH_BUCKET_NUMBER: usize = 500;
 
 const CFLUSH_NUM_ITER: usize = 1 << 11;
 const CFLUSH_SPURIOUS_THRESHOLD: usize = 1;
@@ -231,9 +231,6 @@ pub fn calibrate_flush(
                     miss_histogram[i]
                 );
             }
-            // FIXME
-            // Code duplication for histogram analysis is meh.
-            // Is there a better way ?
 
             for (min, max, med, sum, hist) in &mut [
                 (
@@ -265,7 +262,7 @@ pub fn calibrate_flush(
 
                 if **med == 0 {
                     **sum += hist[i];
-                    if **sum >= CFLUSH_NUM_ITER / 2 {
+                    if **sum >= (CFLUSH_NUM_ITER - hist[hist.len() - 1]) / 2 {
                         **med = i;
                     }
                 }
diff --git a/cache_utils/src/main.rs b/cache_utils/src/main.rs
index 4294960..d3e7a67 100644
--- a/cache_utils/src/main.rs
+++ b/cache_utils/src/main.rs
@@ -14,16 +14,53 @@ use nix::sched::{sched_getaffinity, sched_setaffinity, CpuSet};
 use nix::unistd::Pid;
 use nix::Error::Sys;
 
+use nix::sys::mman;
+use static_assertions::_core::ptr::{null_mut, slice_from_raw_parts};
+
+/* from linux kernel headers.
+#define HUGETLB_FLAG_ENCODE_SHIFT       26
+#define HUGETLB_FLAG_ENCODE_MASK        0x3f
+
+#define HUGETLB_FLAG_ENCODE_64KB        (16 << HUGETLB_FLAG_ENCODE_SHIFT)
+#define HUGETLB_FLAG_ENCODE_512KB       (19 << HUGETLB_FLAG_ENCODE_SHIFT)
+#define HUGETLB_FLAG_ENCODE_1MB         (20 << HUGETLB_FLAG_ENCODE_SHIFT)
+#define HUGETLB_FLAG_ENCODE_2MB         (21 << HUGETLB_FLAG_ENCODE_SHIFT)
+*/
+
+const SIZE: usize = 2 << 20;
+/*
 #[repr(align(4096))]
 struct Page {
     pub mem: [u8; 4096],
 }
-
+*/
 pub fn main() {
-    let p = Box::new(Page { mem: [0; 4096] });
+    let m: &[u8] = unsafe {
+        let p: *mut u8 = mman::mmap(
+            null_mut(),
+            SIZE,
+            mman::ProtFlags::PROT_READ | mman::ProtFlags::PROT_WRITE,
+            mman::MapFlags::MAP_PRIVATE
+                | mman::MapFlags::MAP_ANONYMOUS
+                | mman::MapFlags::MAP_HUGETLB,
+            -1,
+            0,
+        )
+        .unwrap() as *mut u8;
+        /*addr: *mut c_void,
+        length: size_t,
+        prot: ProtFlags,
+        flags: MapFlags,
+        fd: RawFd,
+        offset: off_t*/
 
-    let m: &[u8] = &p.mem;
+        &*slice_from_raw_parts(p, SIZE)
+    };
+    /*
+        let p = Box::new(Page { mem: [0; 4096] });
 
+        let m: &[u8] = &p.mem;
+    */
     let old = sched_getaffinity(Pid::from_raw(0)).unwrap();
 
     for i in 0..(CpuSet::count() - 1) {