cache line alignment

3bda7e20 · Nickolai Zeldovich · 20caefe7 · 3bda7e20 · 3bda7e20 · 3bda7e20
--- a/kalloc.h
+++ b/kalloc.h
@@ -7,6 +7,6 @@ struct kmem {
  struct spinlock lock;
  struct run *freelist;
  uint nfree;
-};
+} __attribute__ ((aligned (CACHELINE)));

 extern struct kmem kmems[NCPU];
--- a/param.h
+++ b/param.h
@@ -13,3 +13,4 @@
 #define MAXNAME      16  // max string names
 #define MINCYCTHRESH 1000000  // min cycles a proc executes on a core before allowed to be stolen
 #define INF          0xFFFFFFFF
+#define CACHELINE    64  // cache line size
--- a/proc.h
+++ b/proc.h
@@ -115,19 +115,19 @@ struct cpu {
  struct proc *proc;           // The currently-running process.
  struct kmem *kmem;           // The per-core memory table
  struct runq *runq;           // The per-core runq
-};
+} __attribute__ ((aligned (CACHELINE)));

 struct runq {
  char name[MAXNAME];
  struct spinlock lock;
  STAILQ_HEAD(runlist, proc) runq;
-};
+} __attribute__ ((aligned (CACHELINE)));

 struct condtab {
  char name[MAXNAME];
  struct spinlock lock;
  struct condvar condtab[NPROC];
-};
+} __attribute__ ((aligned (CACHELINE)));

 extern struct cpu cpus[NCPU];
 extern struct runq runqs[NCPU];