diff options
| -rw-r--r-- | README | 4 | ||||
| -rw-r--r-- | usertests.c | 36 | ||||
| -rw-r--r-- | vm.c | 11 |
3 files changed, 46 insertions, 5 deletions
@@ -20,8 +20,8 @@ The following people made contributions: Cliff Frey (MP) Xiao Yu (MP) -In addition, we are grateful for the patches submitted by Greg Price, -Yandong Mao, and Hitoshi Mitake. +In addition, we are grateful for the patches contributed by Greg +Price, Yandong Mao, and Hitoshi Mitake. The code in the files that constitute xv6 is Copyright 2006-2007 Frans Kaashoek, Robert Morris, and Russ Cox. diff --git a/usertests.c b/usertests.c index 670a4a8..7ec03fc 100644 --- a/usertests.c +++ b/usertests.c @@ -324,6 +324,7 @@ mem(void) void *m1, *m2; int pid, ppid; + printf(1, "mem test\n"); ppid = getpid(); if((pid = fork()) == 0){ m1 = 0; @@ -1332,6 +1333,41 @@ sbrktest(void) wait(); } + // if we run the system out of memory, does it clean up the last + // failed allocation? + sbrk(-(sbrk(0) - oldbrk)); + int pids[32]; + int fds[2]; + if(pipe(fds) != 0){ + printf(1, "pipe() failed\n"); + exit(); + } + for (i = 0; i < sizeof(pids)/sizeof(pids[0]); i++){ + if ((pids[i] = fork()) == 0) { + // allocate the full 640K + sbrk((640 * 1024) - (uint)sbrk(0)); + write(fds[1], "x", 1); + // sit around until killed + while (1) sleep(1000); + } + char scratch; + if (pids[i] != -1) + read(fds[0], &scratch, 1); + } + // if those failed allocations freed up the pages they did allocate, + // we'll be able to allocate here + c = sbrk(4096); + for (i = 0; i < sizeof(pids)/sizeof(pids[0]); i++){ + if (pids[i] == -1) + continue; + kill(pids[i]); + wait(); + } + if (c == (char*)0xffffffff) { + printf(stdout, "failed sbrk leaked memory\n"); + exit(); + } + if(sbrk(0) > oldbrk) sbrk(-(sbrk(0) - oldbrk)); @@ -195,7 +195,8 @@ allocuvm(pde_t *pgdir, char *addr, uint sz) if(pte == 0 || (*pte & PTE_P) == 0){ char *mem = kalloc(); if(mem == 0){ - // XXX clean up? + cprintf("allocuvm out of memory\n"); + deallocuvm(pgdir, addr, sz); return 0; } memset(mem, 0, PGSIZE); @@ -312,13 +313,17 @@ copyuvm(pde_t *pgdir, uint sz) if(*pte & PTE_P){ pa = PTE_ADDR(*pte); if (!(mem = kalloc())) - return 0; + goto bad; memmove(mem, (char *)pa, PGSIZE); if (!mappages(d, (void *)i, PGSIZE, PADDR(mem), PTE_W|PTE_U)) - return 0; + goto bad; } } return d; + +bad: + freevm(d); + return 0; } // Allocate one page table for the machine for the kernel address |