From f561d885d5afd9d5b213bc9e35d2bd091f08994e Mon Sep 17 00:00:00 2001 From: Bahadir Balban Date: Wed, 28 May 2008 23:37:41 +0300 Subject: [PATCH] Flushing pages to vfs will work, but the issue is that while vfs is serving mm0, if it page faults, system deadlocks because mm0 is waiting to be served by vfs. FIX: To fix this, mm0 will need to fork itself and keep a separate thread solely for page fault handling. --- src/api/ipc.c | 12 ++++++------ tasks/fs0/src/syscalls.c | 14 ++++++++++++++ tasks/mm0/src/file.c | 12 +++++++++++- tasks/mm0/src/pagers.c | 6 ++++++ tasks/test0/src/fileio.c | 2 +- tools/l4-qemunew | 2 +- 6 files changed, 39 insertions(+), 9 deletions(-) diff --git a/src/api/ipc.c b/src/api/ipc.c index b09cb12..0ab9338 100644 --- a/src/api/ipc.c +++ b/src/api/ipc.c @@ -85,8 +85,8 @@ int ipc_send(l4id_t recv_tid) /* Do the work */ ipc_msg_copy(sleeper, current); - //printk("(%d) Waking up (%d)\n", current->tid, - // sleeper->tid); + printk("%s: (%d) Waking up (%d)\n", __FUNCTION__, + current->tid, sleeper->tid); /* Wake it up, we can yield here. */ sched_resume_task(sleeper); @@ -100,7 +100,7 @@ int ipc_send(l4id_t recv_tid) list_add_tail(&wq.task_list, &wqhs->task_list); sched_notify_sleep(current); need_resched = 1; - //printk("(%d) waiting for (%d)\n", current->tid, recv_tid); + printk("%s: (%d) waiting for (%d)\n", __FUNCTION__, current->tid, recv_tid); spin_unlock(&wqhr->slock); spin_unlock(&wqhs->slock); return 0; @@ -133,8 +133,8 @@ int ipc_recv(l4id_t senderid) /* Do the work */ ipc_msg_copy(current, sleeper); - //printk("(%d) Waking up (%d)\n", current->tid, - // sleeper->tid); + printk("%s: (%d) Waking up (%d)\n", __FUNCTION__, + current->tid, sleeper->tid); /* Wake it up */ sched_resume_task(sleeper); @@ -149,7 +149,7 @@ int ipc_recv(l4id_t senderid) list_add_tail(&wq.task_list, &wqhr->task_list); sched_notify_sleep(current); need_resched = 1; -// printk("(%d) waiting for (%d) \n", current->tid, current->senderid); + printk("%s: (%d) waiting for (%d) \n", __FUNCTION__, current->tid, current->senderid); spin_unlock(&wqhr->slock); spin_unlock(&wqhs->slock); return 0; diff --git a/tasks/fs0/src/syscalls.c b/tasks/fs0/src/syscalls.c index aae0ca4..3867f3d 100644 --- a/tasks/fs0/src/syscalls.c +++ b/tasks/fs0/src/syscalls.c @@ -30,6 +30,8 @@ int pager_sys_open(l4id_t sender, int fd, unsigned long vnum, unsigned long size { int err; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); + l4_save_ipcregs(); write_mr(L4SYS_ARG0, sender); @@ -104,6 +106,8 @@ int pager_sys_close(l4id_t sender, l4id_t closer, int fd) struct tcb *task; int err; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); + BUG_ON(!(task = find_task(closer))); printf("Deleting fd: %d\n", fd); @@ -132,6 +136,7 @@ int sys_open(l4id_t sender, const char *pathname, int flags, unsigned int mode) int fd; int retval, err; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); /* Get the task */ BUG_ON(!(task = find_task(sender))); @@ -337,6 +342,7 @@ int pager_sys_read(l4id_t sender, unsigned long vnum, unsigned long f_offset, struct vnode *v; int err, retval = 0; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); if (sender != PAGER_TID) { retval = -EINVAL; goto out; @@ -370,6 +376,7 @@ int pager_update_stats(l4id_t sender, unsigned long vnum, struct vnode *v; int retval = 0; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); if (sender != PAGER_TID) { retval = -EINVAL; goto out; @@ -402,6 +409,7 @@ int pager_sys_write(l4id_t sender, unsigned long vnum, unsigned long f_offset, struct vnode *v; int err, retval = 0; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); if (sender != PAGER_TID) { retval = -EINVAL; goto out; @@ -419,6 +427,9 @@ int pager_sys_write(l4id_t sender, unsigned long vnum, unsigned long f_offset, goto out; } + printf("%s/%s: Writing to vnode %lu, at pgoff 0x%x, %d pages, buf at 0x%x\n", + __TASKNAME__, __FUNCTION__, vnum, f_offset, npages, pagebuf); + /* * If the file is extended, write silently extends it. * But we expect an explicit pager_update_stats from the @@ -430,7 +441,9 @@ int pager_sys_write(l4id_t sender, unsigned long vnum, unsigned long f_offset, } out: + printf("%s/%s: Returning ipc result.\n", __TASKNAME__, __FUNCTION__); l4_ipc_return(retval); + printf("%s/%s: Done.\n", __TASKNAME__, __FUNCTION__); return 0; } @@ -482,6 +495,7 @@ int sys_readdir(l4id_t sender, int fd, void *buf, int count) struct dentry *d; struct tcb *t; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); /* Get the task */ BUG_ON(!(t = find_task(sender))); diff --git a/tasks/mm0/src/file.c b/tasks/mm0/src/file.c index df2d42e..e15d493 100644 --- a/tasks/mm0/src/file.c +++ b/tasks/mm0/src/file.c @@ -55,6 +55,8 @@ int vfs_read(unsigned long vnum, unsigned long file_offset, { int err; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); + l4_save_ipcregs(); write_mr(L4SYS_ARG0, vnum); @@ -90,6 +92,8 @@ int vfs_receive_sys_open(l4id_t sender, l4id_t opener, int fd, struct vm_file *vmfile; struct tcb *t; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); + /* Check argument validity */ if (sender != VFS_TID) { l4_ipc_return(-EPERM); @@ -214,6 +218,7 @@ int vfs_write(unsigned long vnum, unsigned long file_offset, { int err; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); l4_save_ipcregs(); write_mr(L4SYS_ARG0, vnum); @@ -241,6 +246,7 @@ int vfs_close(l4id_t sender, int fd) { int err; + printf("%s/%s Sending to %d\n", __TASKNAME__, __FUNCTION__, VFS_TID); l4_save_ipcregs(); write_mr(L4SYS_ARG0, sender); @@ -250,6 +256,7 @@ int vfs_close(l4id_t sender, int fd) printf("%s: L4 IPC Error: %d.\n", __FUNCTION__, err); return err; } + printf("%s/%s Received from %d\n", __TASKNAME__, __FUNCTION__, VFS_TID); /* Check if syscall was successful */ if ((err = l4_get_retval()) < 0) { @@ -267,6 +274,7 @@ int vfs_update_file_stats(struct vm_file *f) { int err; + printf("%s/%s\n", __TASKNAME__, __FUNCTION__); l4_save_ipcregs(); write_mr(L4SYS_ARG0, vm_file_to_vnum(f)); @@ -373,7 +381,7 @@ int sys_close(l4id_t sender, int fd) l4_ipc_return(retval); return 0; } - + /* Close the file descriptor. */ retval = fd_close(sender, fd); printf("%s: Closed fd %d. Returning %d\n", @@ -454,6 +462,7 @@ copy: copy_offset = (unsigned long)buf; page_copy(head, task_virt_to_page(task, copy_offset), cursor_offset, copy_offset & PAGE_MASK, copysize); + head->flags |= VM_DIRTY; left -= copysize; last_pgoff = head->offset; @@ -473,6 +482,7 @@ copy: page_copy(this, task_virt_to_page(task, copy_offset), 0, 0, copysize); + this->flags |= VM_DIRTY; left -= copysize; last_pgoff = this->offset; } diff --git a/tasks/mm0/src/pagers.c b/tasks/mm0/src/pagers.c index b68e853..4a7e609 100644 --- a/tasks/mm0/src/pagers.c +++ b/tasks/mm0/src/pagers.c @@ -84,9 +84,15 @@ int file_page_out(struct vm_object *vm_obj, unsigned long page_offset) if (!(page->flags & VM_DIRTY)) return 0; + paddr = (void *)page_to_phys(page); + vaddr = phys_to_virt(paddr); + /* Map the page to vfs task */ l4_map(paddr, vaddr, 1, MAP_USR_RW_FLAGS, VFS_TID); + printf("%s/%s: Writing to vnode %d, at pgoff 0x%x, %d pages, buf at 0x%x\n", + __TASKNAME__, __FUNCTION__, vm_file_to_vnum(f), page_offset, 1, vaddr); + /* Syscall to vfs to write page back to file. */ if ((err = vfs_write(vm_file_to_vnum(f), page_offset, 1, vaddr)) < 0) goto out_err; diff --git a/tasks/test0/src/fileio.c b/tasks/test0/src/fileio.c index 212d6df..8f74af1 100644 --- a/tasks/test0/src/fileio.c +++ b/tasks/test0/src/fileio.c @@ -21,7 +21,7 @@ int fileio2(void) perror("OPEN"); return -1; } - printf("Created newfile.txt\n"); + printf("Created newfile2.txt\n"); printf("%s: write.\n", __TASKNAME__); if ((int)(cnt = write(fd, str, strlen(str))) < 0) { diff --git a/tools/l4-qemunew b/tools/l4-qemunew index c202ffc..d3ca3fe 100755 --- a/tools/l4-qemunew +++ b/tools/l4-qemunew @@ -1,6 +1,6 @@ cd build #arm-none-eabi-insight & -/opt/bin/qemu-system-arm -s -kernel final.axf -nographic -m 128 -M versatilepb & +/opt/qemu/bin/qemu-system-arm -s -kernel final.axf -nographic -m 128 -M versatilepb & arm-none-linux-gnueabi-insight ; pkill qemu-system-arm #arm-none-eabi-gdb ; pkill qemu-system-arm cd ..