almost-tmpfs

107ec052 · Nickolai Zeldovich · decfb4f4 · 107ec052 · 107ec052 · 107ec052
--- a/bio.c
+++ b/bio.c
@@ -30,6 +30,8 @@

 static struct ns *bufns;

+enum { writeback = 0 };
+
 void
 binit(void)
 {
@@ -143,7 +145,8 @@ bwrite(struct buf *b)
  if((b->flags & B_BUSY) == 0)
    panic("bwrite");
  b->flags |= B_DIRTY;
-  iderw(b);
+  if (writeback)
+    iderw(b);
 }

 // Release the buffer b.

--- a/file.h
+++ b/file.h
@@ -19,6 +19,7 @@ struct inode {
  int flags;          // I_BUSY, I_VALID
  struct condvar cv;
  struct spinlock lock;
+  char lockname[16];

  short type;         // copy of disk inode
  short major;

--- a/fs.c
+++ b/fs.c
@@ -259,8 +259,9 @@ iget(uint dev, uint inum)
  ip->inum = inum;
  ip->ref = 1;
  ip->flags = I_BUSY;
-  initlock(&ip->lock, "icache-lock");
-  initcondvar(&ip->cv, "icache-cv");
+  snprintf(ip->lockname, sizeof(ip->lockname), "cv:ino:%d", ip->inum);
+  initlock(&ip->lock, ip->lockname+3);
+  initcondvar(&ip->cv, ip->lockname);
  if (ns_insert(ins, ip->inum, ip) < 0) {
    rcu_delayed(ip, kmfree);
    goto retry;

--- a/param.h
+++ b/param.h
@@ -3,7 +3,7 @@
 #define NCPU          2  // maximum number of CPUs
 #define NOFILE       16  // open files per process
 #define NFILE       100  // open files per system
-#define NBUF         10  // size of disk block cache
+#define NBUF       1000  // size of disk block cache
 #define NINODE       50  // maximum number of active i-nodes
 #define NDEV         10  // maximum major device number
 #define ROOTDEV       1  // device number of file system root disk