Merge branch 'scale-amd64' of git+ssh://pdos.csail.mit.edu/home/am0/6.828/xv6 into scale-amd64

706ea3fe · Nickolai Zeldovich · 2a53d3c4 · 89ae1d13 · 706ea3fe · 706ea3fe
--- a/Makefile
+++ b/Makefile
@@ -19,6 +19,7 @@ AS = $(TOOLPREFIX)gas
 LD = $(TOOLPREFIX)ld
 NM = $(TOOLPREFIX)nm
 OBJCOPY = $(TOOLPREFIX)objcopy
+STRIP = $(TOOLPREFIX)strip
 COMFLAGS := -fno-pic -static -fno-builtin -fno-strict-aliasing -O2 -Wall \
 	    -MD -ggdb -m64 -Werror -fms-extensions -mno-sse \
@@ -79,7 +80,7 @@ OBJS = \
 	incbin.o
 OBJS := $(addprefix $(O)/, $(OBJS))
-ULIB = ulib.o usys.o printf.o umalloc.o uthread.o
+ULIB = ulib.o usys.o printf.o umalloc.o uthread.o fmt.o
 ULIB := $(addprefix $(O)/, $(ULIB))
 UPROGS= \
@@ -142,10 +143,14 @@ xv6memfs.img: bootblock kernelmemfs
 	dd if=bootblock of=xv6memfs.img conv=notrunc
 	dd if=kernelmemfs of=xv6memfs.img seek=1 conv=notrunc
-$(O)/_%: $(O)/%.o $(ULIB)
+$(O)/_%.unstripped: $(O)/%.o $(ULIB)
 	@echo "  LD     $@"
 	$(Q)$(LD) $(LDFLAGS) -N -e main -Ttext 0x100000 -o $@ $^
+$(O)/_%: $(O)/_%.unstripped
+	@echo "  STRIP  $@"
+	$(Q)$(STRIP) -o $@ $<
 $(O)/mkfs: mkfs.c fs.h
 	gcc -m32 -Werror -Wall -o $@ mkfs.c
@@ -162,7 +167,7 @@ mscan.kern: $(O)/kernel
 -include *.d
 -include $(O)/*.d
-.PRECIOUS: $(O)/%.o
+.PRECIOUS: $(O)/%.o $(O)/_%.unstripped
 .PHONY: clean qemu gdb rsync
 ##

--- a/compiler.h
+++ b/compiler.h
@@ -2,3 +2,11 @@
 #define __mpalign__ __attribute__((aligned(CACHELINE)))
 #define __noret__   __attribute__((noreturn))
 #define barrier() __asm volatile("" ::: "memory")
+#ifdef __cplusplus
+#define BEGIN_DECLS extern "C" {
+#define END_DECLS   }
+#else
+#define BEGIN_DECLS
+#define END_DECLS
+#endif
--- a/fmt.cc
+++ b/fmt.cc
 extern "C" {
 #include "types.h"
-#include "kernel.h"
 #include <stddef.h>
 #include <stdarg.h>
 #include "fmt.h"
+#include "lib.h"
+unsigned int strlen(const char*);
 }
 //

--- a/ipc.h
+++ b/ipc.h
 struct ipcctl {
-  volatile char done;
+  volatile char done:1;
+  volatile char submitted:1;
+  off_t off;
  volatile long result;
 };
--- a/kernel.h
+++ b/kernel.h
@@ -294,7 +294,7 @@ void*           memmove(void*, const void*, u32);
 void*           memset(void*, int, u32);
 void*           memcpy(void*, const void *, u32);
 char*           safestrcpy(char*, const char*, u32);
-int             strlen(const char*);
+unsigned int    strlen(const char*);
 int             strncmp(const char*, const char*, u32);
 char*           strncpy(char*, const char*, u32);
 int             strcmp(const char *p, const char *q);

--- a/kernlet.c
+++ b/kernlet.c
@@ -32,6 +32,8 @@ pread_work(struct work *w, void *a0, void *a1, void *a2, void *a3)
  ipc->result = r;
  barrier();
  ipc->done = 1;
+  iput(ip);
 }
 static struct work *
@@ -57,18 +59,25 @@ sys_kernlet(int fd, size_t count, off_t off)
 {
  struct file *f;
  struct work *w;
+  struct ipcctl *ipc = (struct ipcctl *)myproc()->vmap->kshared;
  if(fd < 0 || fd >= NOFILE || (f=myproc()->ofile[fd]) == 0)
    return -1;
  if(f->type != FD_INODE)
    return -1;
+  fetchadd(&f->ip->ref, 1);
  w = pread_allocwork(f->ip, myproc()->vmap->kshared, count, off);
-  if (w == NULL)
+  if (w == NULL) {
+    iput(f->ip);
    return -1;
+  }
  if (wq_push(w) < 0) {
+    iput(f->ip);
    freework(w);
    return -1;
  }
+  ipc->off = off;
+  ipc->submitted = 1;
  return 0;
 }
--- a/net.mk
+++ b/net.mk
@@ -16,12 +16,12 @@ UPROGS += \
 CFLAGS   += -Ilwip/src/include -Inet -Ilwip/src/include/ipv4 -I. -DLWIP
 CXXFLAGS += -Ilwip/src/include -Inet -Ilwip/src/include/ipv4 -I. -DLWIP
-LWIP_CFLAGS = -fno-pic -static -fno-builtin -fno-strict-aliasing -O2 -Wall -MD -ggdb \
+LWIP_CFLAGS = $(COMFLAGS) -std=c99 \
-	 -m64 -Werror -std=c99 -fms-extensions -mno-sse -mcmodel=large -I$(QEMUSRC) \
+	    -Wno-attributes \
-	 -fno-omit-frame-pointer -DHW_$(HW) -include param.h -include compiler.h \
+	    -Wno-address \
-	 -DXV6 -Wno-attributes -Wno-address -Wno-char-subscripts \
+	    -Wno-char-subscripts \
-	 -Wno-unused-but-set-variable -Wno-format
+	    -Wno-unused-but-set-variable \
-LWIP_CFLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 && echo -fno-stack-protector)
+	    -Wno-format
 LWIP_INCLUDES := \
 	-Ilwip/src/include \

--- a/preadtest.cc
+++ b/preadtest.cc
@@ -2,6 +2,7 @@
 #include "stat.h"
 #include "fcntl.h"
 #include "user.h"
+#include "lib.h"
 #include "amd64.h"
 #include "ipc.h"
@@ -24,6 +25,31 @@ kernlet_pread(int fd, size_t count, off_t off)
    die("kernlet");
 }
+static ssize_t
+xpread(int fd, void *buf, size_t count, off_t off)
+{
+  if (ipcctl->submitted) {
+    while (ipcctl->done == 0)
+      nop_pause();
+    if (ipcctl->result == -1)
+      goto slow;
+    if (off < ipcctl->off)
+      goto slow;
+    if (off > ipcctl->off + ipcctl->result)
+      goto slow;
+    char *kbuf = (char*) (KSHARED+4096);
+    off_t kbufoff = off - ipcctl->off;
+    size_t kbufcount = MIN(count, ipcctl->result - kbufoff);
+    memmove(buf, kbuf+kbufoff, kbufcount);
+    return kbufcount;
+  }
+slow:
+  return pread(fd, buf, count, off);
+}
 int
 main(int ac, char **av)
 {
@@ -43,13 +69,8 @@ main(int ac, char **av)
  for (k = 0; k < FSIZE; k+=PSIZE) {
    kernlet_pread(fd, PSIZE, k);
-    while (ipcctl->done == 0)
-        nop_pause();
-    die("preadtest: %d\n", (int)ipcctl->result);
    for (i = k; i < k+PSIZE; i+=BSIZE)
-      if (pread(fd, buf, BSIZE, i) != BSIZE)
+      if (xpread(fd, buf, BSIZE, i) != BSIZE)
        die("pread failed");
  }
  t1 = rdtsc();

--- a/printf.cc
+++ b/printf.cc
 #include "types.h"
 #include "stat.h"
 #include "user.h"
+extern "C" {
 #include <stdarg.h>
+#include "fmt.h"
-static void
-printint(void (*putch) (void*, char), void *putarg,
-	 s64 xx, int base, int sgn)
-{
-  const static char digits[] = "0123456789ABCDEF";
-  char buf[21];
-  int i, neg;
-  s64 x;
-  neg = 0;
-  if(sgn && xx < 0){
-    neg = 1;
-    x = -xx;
-  } else {
-    x = xx;
-  }
-  i = 0;
-  do{
-    buf[i++] = digits[x % base];
-  }while((x /= base) != 0);
-  if(neg)
-    buf[i++] = '-';
-  while(--i >= 0)
-    putch(putarg, buf[i]);
-}
-// Only understands %d, %x, %p, %s.
-void
-vprintfmt(void (*putch) (void*, char), void *putarg,
-          const char *fmt, va_list ap)
-{
-  const char *s;
-  int c, i, state;
-  state = 0;
-  for(i = 0; fmt[i]; i++){
-    c = fmt[i] & 0xff;
-    if(state == 0){
-      if(c == '%'){
-        state = '%';
-      } else {
-        putch(putarg, c);
-      }
-    } else if(state == '%'){
-      if(c == 'd'){
-        printint(putch, putarg, va_arg(ap, u32), 10, 1);
-      } else if(c == 'x') {
-        printint(putch, putarg, va_arg(ap, u32), 16, 0);
-      } else if(c == 'l') {
-        state = 'l';
-        continue;
-      } else if(c == 's'){
-        s = (const char*) va_arg(ap, const char*);
-        if(s == 0)
-          s = "(null)";
-        while(*s != 0){
-          putch(putarg, *s);
-          s++;
-        }
-      } else if(c == 'c'){
-        putch(putarg, va_arg(ap, u32));
-      } else if(c == '%'){
-        putch(putarg, c);
-      } else {
-        // Unknown % sequence.  Print it to draw attention.
-        putch(putarg, '%');
-        putch(putarg, c);
-      }
-      state = 0;
-    } else if(state == 'l') {
-      if(c == 'x') {
-        printint(putch, putarg, va_arg(ap, u64), 16, 0);
-      }
-      else if(c == 'u') {
-        printint(putch, putarg, va_arg(ap, u64), 10, 0);
-      }
-      else {
-        // Unknown % sequence.  Print it to draw attention.
-        putch(putarg, '%');
-        putch(putarg, c);
-      }
-      state = 0;
-    }
-  }
 }
 // Print to the given fd.
 static void
-writec(void *arg, char c)
+writec(int c, void *arg)
 {
  int fd = (int) (u64) arg;
  write(fd, &c, 1);
@@ -117,7 +31,7 @@ struct bufstate {
 };
 static void
-writebuf(void *arg, char c)
+writebuf(int c, void *arg)
 {
  struct bufstate *bs = (bufstate*) arg;
  if (bs->p < bs->e) {

--- a/string.cc
+++ b/string.cc
@@ -92,7 +92,7 @@ safestrcpy(char *s, const char *t, u32 n)
  return os;
 }
-int
+unsigned int
 strlen(const char *s)
 {
  int n;

--- a/sysfile.cc
+++ b/sysfile.cc
@@ -79,12 +79,16 @@ ssize_t
 sys_pread(int fd, void *ubuf, size_t count, off_t offset)
 {
  struct file *f;
+  uptr i = (uptr)ubuf;
  int r;
  if(fd < 0 || fd >= NOFILE || (f=myproc()->ofile[fd]) == 0)
    return -1;
-  // XXX(sbw) assuming ubuf is ok
+  for(uptr va = PGROUNDDOWN(i); va < i+count; va = va + PGSIZE)
+    if(pagefault(myproc()->vmap, va, 0) < 0)
+      return -1;
  if(f->type == file::FD_INODE){
    ilock(f->ip, 0);
    if(f->ip->type == 0)

--- a/ulib.cc
+++ b/ulib.cc
--- a/user.h
+++ b/user.h
+BEGIN_DECLS
 struct stat;
 // system calls
-extern "C" {
 int fork(int);
 int exit(void) __attribute__((noreturn));
 int wait(void);
@@ -28,7 +28,6 @@ int unmap(void *addr, int len);
 void halt(void);
 ssize_t pread(int, void*, size_t, off_t);
 int kernlet(int, size_t, off_t);
-}
 // ulib.c
 int stat(char*, struct stat*);
@@ -46,11 +45,10 @@ void free(void*);
 int atoi(const char*);
 // uthread.S
-extern "C" {
 int forkt(void *sp, void *pc, void *arg);
-}
 // printf.c
 void printf(int, const char*, ...);
 void snprintf(char *buf, unsigned int n, const char *fmt, ...);
 void die(const char* errstr, ...) __attribute__((noreturn));
+END_DECLS
--- a/usertests.cc
+++ b/usertests.cc
@@ -1544,6 +1544,50 @@ unopentest(void)
  printf(stdout, "concurrent unlink/open ok\n");
 }
+void
+preads(void)
+{
+  static const int fsize = (64 << 10);
+  static const int bsize = 4096;
+  static const int nprocs = 4;
+  static const int iters = 100;
+  static char buf[bsize];
+  int fd;
+  int pid;
+  printf(1, "concurrent preads\n");
+  fd = open("preads.x", O_CREATE|O_RDWR);
+  if (fd < 0)
+    die("preads: open failed");
+  for (int i = 0; i < fsize/bsize; i++)
+    if (write(fd, buf, bsize) != bsize)
+      die("preads: write failed");
+  close(fd);
+  for (int i = 0; i < nprocs; i++) {
+    pid = fork(0);
+    if (pid < 0)
+      die("preads: fork failed");
+    if (pid == 0)
+      break;
+  }
+  for (int k = 0; k < iters; k++) {
+    fd = open("preads.x", O_RDONLY);
+    for (int i = 0; i < fsize; i+=bsize)
+      if (pread(fd, buf, bsize, i) != bsize)
+        die("preads: pread failed");
+    close(fd);
+  }
+  if (pid == 0)
+    exit();
+  printf(1, "concurrent preads OK\n");
+}
 int
 main(int argc, char *argv[])
 {
@@ -1567,6 +1611,7 @@ main(int argc, char *argv[])
  writetest();
  writetest1();
  createtest();
+  preads();
  // mem();
  pipe1();