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procfs_read/write(): rewrite synchronization for scalability and correctness

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This commit is contained in:
Balazs Gerofi
2016-12-28 14:17:17 +09:00
parent 536ce9f927
commit 40978d162e
6 changed files with 162 additions and 152 deletions
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1
executer/kernel/mcctrl/control.c
View File

@ -1214,6 +1214,7 @@ int mcexec_open_exec(ihk_os_t os, char * __user filename)
INIT_LIST_HEAD(&ppd->wq_req_list);
INIT_LIST_HEAD(&ppd->wq_list_exact);
init_waitqueue_head(&ppd->wq_prepare);
init_waitqueue_head(&ppd->wq_procfs);
spin_lock_init(&ppd->wq_list_lock);
memset(&ppd->cpu_set, 0, sizeof(cpumask_t));
ppd->ikc_target_cpu = 0;

3
executer/kernel/mcctrl/ikc.c
View File

@ -80,7 +80,7 @@ static int syscall_packet_handler(struct ihk_ikc_channel_desc *c,
break;
case SCD_MSG_PROCFS_ANSWER:
procfs_answer(pisp->arg, pisp->err);
procfs_answer(usrdata, pisp->pid);
break;
case SCD_MSG_SEND_SIGNAL:
@ -288,6 +288,7 @@ int prepare_ikc_channels(ihk_os_t os)
ihk_ikc_listen_port(os, &usrdata->listen_param);
memcpy(&usrdata->listen_param2, &listen_param2, sizeof listen_param2);
ihk_ikc_listen_port(os, &usrdata->listen_param2);
init_waitqueue_head(&usrdata->wq_procfs);
for (i = 0; i < MCCTRL_PER_PROC_DATA_HASH_SIZE; ++i) {
INIT_LIST_HEAD(&usrdata->per_proc_data_hash[i]);

5
executer/kernel/mcctrl/mcctrl.h
View File

@ -197,6 +197,7 @@ struct mcctrl_per_proc_data {
struct list_head wq_list_exact;
ihk_spinlock_t wq_list_lock;
wait_queue_head_t wq_prepare;
wait_queue_head_t wq_procfs;
struct list_head per_thread_data_hash[MCCTRL_PER_THREAD_DATA_HASH_SIZE];
rwlock_t per_thread_data_hash_lock[MCCTRL_PER_THREAD_DATA_HASH_SIZE];
@ -283,7 +284,7 @@ struct mcctrl_usrdata {
int job_pos;
int mcctrl_dma_abort;
unsigned long last_thread_exec;
wait_queue_head_t wq_procfs;
struct list_head per_proc_data_hash[MCCTRL_PER_PROC_DATA_HASH_SIZE];
rwlock_t per_proc_data_hash_lock[MCCTRL_PER_PROC_DATA_HASH_SIZE];
@ -351,7 +352,7 @@ struct procfs_file {
char fname[PROCFS_NAME_MAX]; /* procfs filename (request) */
};
void procfs_answer(unsigned int arg, int err);
void procfs_answer(struct mcctrl_usrdata *ud, int pid);
int procfsm_packet_handler(void *os, int msg, int pid, unsigned long arg);
void add_tid_entry(int osnum, int pid, int tid);
void add_pid_entry(int osnum, int pid);

256
executer/kernel/mcctrl/procfs.c
View File

@ -59,7 +59,6 @@ static const struct procfs_entry base_entry_stuff[];
static const struct file_operations mckernel_forward_ro;
static const struct file_operations mckernel_forward;
static DECLARE_WAIT_QUEUE_HEAD(procfsq);
static ssize_t mckernel_procfs_read(struct file *file, char __user *buf,
size_t nbytes, loff_t *ppos);
@ -106,14 +105,28 @@ getpath(struct procfs_list_entry *e, char *buf, int bufsize)
/**
* \brief Process SCD_MSG_PROCFS_ANSWER message.
*
* \param arg sent argument
* \param err error info (redundant)
* \param ud mcctrl_usrdata pointer
* \param pid PID of the requesting process
*/
void
procfs_answer(unsigned int arg, int err)
void procfs_answer(struct mcctrl_usrdata *ud, int pid)
{
dprintk("procfs: received SCD_MSG_PROCFS_ANSWER message(err = %d).\n", err);
wake_up_interruptible(&procfsq);
struct mcctrl_per_proc_data *ppd = NULL;
if (pid > 0) {
ppd = mcctrl_get_per_proc_data(ud, pid);
if (unlikely(!ppd)) {
kprintf("%s: ERROR: no per-process structure for PID %d\n",
__FUNCTION__, pid);
return;
}
}
wake_up_all(pid > 0 ? &ppd->wq_procfs : &ud->wq_procfs);
if (pid > 0) {
mcctrl_put_per_proc_data(ppd);
}
}
static struct procfs_list_entry *
@ -495,16 +508,17 @@ procfs_exit(int osnum)
* This function conforms to the 2) way of fs/proc/generic.c
* from linux-2.6.39.4.
*/
static ssize_t
mckernel_procfs_read(struct file *file, char __user *buf, size_t nbytes,
loff_t *ppos)
static ssize_t __mckernel_procfs_read_write(
struct file *file,
char __user *buf, size_t nbytes,
loff_t *ppos, int read_write)
{
struct inode * inode = file->f_inode;
char *kern_buffer = NULL;
int order = 0;
volatile struct procfs_read *r = NULL;
struct ikc_scd_packet isp;
int ret;
int ret, osnum, pid, retw;
unsigned long pbuf;
unsigned long count = nbytes;
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,10,0)
@ -515,16 +529,63 @@ mckernel_procfs_read(struct file *file, char __user *buf, size_t nbytes,
#endif
loff_t offset = *ppos;
char pathbuf[PROCFS_NAME_MAX];
char *path;
path = getpath(e, pathbuf, 256);
dprintk("mckernel_procfs_read: invoked for %s, offset: %lu, count: %d\n",
path, offset, count);
char *path, *p;
ihk_os_t os = NULL;
struct mcctrl_usrdata *udp = NULL;
struct mcctrl_per_proc_data *ppd = NULL;
if (count <= 0 || offset < 0) {
return 0;
}
path = getpath(e, pathbuf, PROCFS_NAME_MAX);
dprintk("%s: invoked for %s, offset: %lu, count: %lu\n",
__FUNCTION__, path,
(unsigned long)offset, count);
/* Verify OS number */
ret = sscanf(path, "mcos%d/", &osnum);
if (ret != 1) {
printk("%s: error: couldn't determine OS number\n", __FUNCTION__);
return -EINVAL;
}
if (osnum != e->osnum) {
printk("%s: error: OS numbers don't match\n", __FUNCTION__);
return -EINVAL;
}
/* Is this request for a specific process? */
p = strchr(path, '/') + 1;
ret = sscanf(p, "%d/", &pid);
if (ret != 1) {
pid = -1;
}
os = osnum_to_os(osnum);
if (!os) {
printk("%s: error: no IHK OS data found for OS %d\n",
__FUNCTION__, osnum);
return -EINVAL;
}
udp = ihk_host_os_get_usrdata(os);
if (!udp) {
printk("%s: error: no MCCTRL data found for OS %d\n",
__FUNCTION__, osnum);
return -EINVAL;
}
if (pid > 0) {
ppd = mcctrl_get_per_proc_data(udp, pid);
if (unlikely(!ppd)) {
printk("%s: error: no per-process structure for PID %d",
__FUNCTION__, pid);
return -EINVAL;
}
}
while ((1 << order) < count) ++order;
if (order > 12) {
order -= 12;
@ -536,8 +597,9 @@ mckernel_procfs_read(struct file *file, char __user *buf, size_t nbytes,
/* NOTE: we need physically contigous memory to pass through IKC */
kern_buffer = (char *)__get_free_pages(GFP_KERNEL, order);
if (!kern_buffer) {
printk("mckernel_procfs_read(): ERROR: allocating kernel buffer\n");
return -ENOMEM;
printk("%s: ERROR: allocating kernel buffer\n", __FUNCTION__);
ret = -ENOMEM;
goto out;
}
pbuf = virt_to_phys(kern_buffer);
@ -553,13 +615,15 @@ mckernel_procfs_read(struct file *file, char __user *buf, size_t nbytes,
r->status = 0;
r->offset = offset;
r->count = count;
r->readwrite = 0;
r->readwrite = read_write;
strncpy((char *)r->fname, path, PROCFS_NAME_MAX);
isp.msg = SCD_MSG_PROCFS_REQUEST;
isp.ref = 0;
isp.arg = virt_to_phys(r);
isp.pid = pid;
ret = mcctrl_ikc_send(osnum_to_os(e->osnum), 0, &isp);
ret = mcctrl_ikc_send(osnum_to_os(e->osnum),
(pid > 0) ? ppd->ikc_target_cpu : 0, &isp);
if (ret < 0) {
goto out; /* error */
@ -567,29 +631,61 @@ mckernel_procfs_read(struct file *file, char __user *buf, size_t nbytes,
/* Wait for a reply. */
ret = -EIO; /* default exit code */
dprintk("now wait for a relpy\n");
dprintk("%s: waiting for reply\n", __FUNCTION__);
/* Wait for the status field of the procfs_read structure set ready. */
if (wait_event_interruptible_timeout(procfsq, r->status != 0, HZ) == 0) {
kprintf("ERROR: mckernel_procfs_read: timeout (1 sec).\n");
retry_wait:
/* Wait for the status field of the procfs_read structure,
* wait on per-process or OS specific data depending on
* who the request is for.
*/
if (pid > 0) {
retw = wait_event_interruptible_timeout(ppd->wq_procfs,
r->status != 0, HZ);
}
else {
retw = wait_event_interruptible_timeout(udp->wq_procfs,
r->status != 0, HZ);
}
/* Timeout? */
if (retw == 0 && r->status == 0) {
printk("%s: error: timeout (1 sec)\n", __FUNCTION__);
goto out;
}
/* Interrupted? */
else if (retw == -ERESTARTSYS) {
ret = -ERESTART;
goto out;
}
/* Were we woken up by a reply to another procfs request? */
else if (r->status == 0) {
/* TODO: r->status is not set atomically, we could be woken
* up with status == 0 and it could change to 1 while in this
* code, we could potentially miss the wake_up()...
*/
printk("%s: stale wake-up, retrying\n", __FUNCTION__);
goto retry_wait;
}
/* Wake up and check the result. */
dprintk("mckernel_procfs_read: woke up. ret: %d, eof: %d\n", r->ret, r->eof);
dprintk("%s: woke up. ret: %d, eof: %d\n",
__FUNCTION__, r->ret, r->eof);
if (r->ret > 0) {
if (read_write == 0) {
if (copy_to_user(buf, kern_buffer, r->ret)) {
kprintf("ERROR: mckernel_procfs_read: copy_to_user failed.\n");
printk("%s: ERROR: copy_to_user failed.\n", __FUNCTION__);
ret = -EFAULT;
goto out;
}
}
*ppos += r->ret;
}
ret = r->ret;
out:
if (ppd)
mcctrl_put_per_proc_data(ppd);
if (kern_buffer)
free_pages((uintptr_t)kern_buffer, order);
if (r)
@ -598,107 +694,17 @@ out:
return ret;
}
static ssize_t
mckernel_procfs_write(struct file *file, const char __user *buf, size_t nbytes,
loff_t *ppos)
static ssize_t mckernel_procfs_read(struct file *file,
char __user *buf, size_t nbytes, loff_t *ppos)
{
struct inode * inode = file->f_inode;
char *kern_buffer = NULL;
int order = 0;
volatile struct procfs_read *r = NULL;
struct ikc_scd_packet isp;
int ret;
unsigned long pbuf;
unsigned long count = nbytes;
#if LINUX_VERSION_CODE < KERNEL_VERSION(3,10,0)
struct proc_dir_entry *dp = PDE(inode);
struct procfs_list_entry *e = dp->data;
#else
struct procfs_list_entry *e = PDE_DATA(inode);
#endif
loff_t offset = *ppos;
char pathbuf[PROCFS_NAME_MAX];
char *path;
path = getpath(e, pathbuf, 256);
dprintk("mckernel_procfs_read: invoked for %s, offset: %lu, count: %d\n",
path, offset, count);
if (count <= 0 || offset < 0) {
return 0;
return __mckernel_procfs_read_write(file, buf, nbytes, ppos, 0);
}
while ((1 << order) < count) ++order;
if (order > 12) {
order -= 12;
}
else {
order = 1;
}
/* NOTE: we need physically contigous memory to pass through IKC */
kern_buffer = (char *)__get_free_pages(GFP_KERNEL, order);
if (!kern_buffer) {
printk("mckernel_procfs_read(): ERROR: allocating kernel buffer\n");
return -ENOMEM;
}
if (copy_from_user(kern_buffer, buf, nbytes)) {
ret = -EFAULT;
goto out;
}
pbuf = virt_to_phys(kern_buffer);
r = kmalloc(sizeof(struct procfs_read), GFP_KERNEL);
if (r == NULL) {
ret = -ENOMEM;
goto out;
}
dprintk("offset: %lx, count: %d, cpu: %d\n", offset, count, e->cpu);
r->pbuf = pbuf;
r->eof = 0;
r->ret = -EIO; /* default */
r->status = 0;
r->offset = offset;
r->count = count;
r->readwrite = 1;
strncpy((char *)r->fname, path, PROCFS_NAME_MAX);
isp.msg = SCD_MSG_PROCFS_REQUEST;
isp.ref = 0;
isp.arg = virt_to_phys(r);
ret = mcctrl_ikc_send(osnum_to_os(e->osnum), 0, &isp);
if (ret < 0) {
goto out; /* error */
}
/* Wait for a reply. */
ret = -EIO; /* default exit code */
dprintk("now wait for a relpy\n");
/* Wait for the status field of the procfs_read structure set ready. */
if (wait_event_interruptible_timeout(procfsq, r->status != 0, HZ) == 0) {
kprintf("ERROR: mckernel_procfs_read: timeout (1 sec).\n");
goto out;
}
/* Wake up and check the result. */
dprintk("mckernel_procfs_read: woke up. ret: %d, eof: %d\n", r->ret, r->eof);
if (r->ret > 0) {
*ppos += r->ret;
}
ret = r->ret;
out:
if(kern_buffer)
free_pages((uintptr_t)kern_buffer, order);
if(r)
kfree((void *)r);
return ret;
static ssize_t mckernel_procfs_write(struct file *file,
const char __user *buf, size_t nbytes, loff_t *ppos)
{
return __mckernel_procfs_read_write(file,
(char __user *)buf, nbytes, ppos, 1);
}
static loff_t

4
kernel/host.c
View File

@ -532,7 +532,7 @@ static void syscall_channel_send(struct ihk_ikc_channel_desc *c,
}
extern unsigned long do_kill(struct thread *, int, int, int, struct siginfo *, int ptracecont);
extern void process_procfs_request(unsigned long rarg);
extern void process_procfs_request(struct ikc_scd_packet *rpacket);
extern void terminate_host(int pid);
extern void debug_log(long);
@ -640,7 +640,7 @@ static int syscall_packet_handler(struct ihk_ikc_channel_desc *c,
break;
case SCD_MSG_PROCFS_REQUEST:
process_procfs_request(packet->arg);
process_procfs_request(packet);
ret = 0;
break;

5
kernel/procfs.c
View File

@ -76,9 +76,9 @@ procfs_delete_thread(struct thread *thread)
*
* \param rarg returned argument
*/
void
process_procfs_request(unsigned long rarg)
void process_procfs_request(struct ikc_scd_packet *rpacket)
{
unsigned long rarg = rpacket->arg;
unsigned long parg, pbuf;
struct thread *thread = NULL;
struct process *proc = NULL;
@ -633,6 +633,7 @@ dataunavail:
packet.msg = SCD_MSG_PROCFS_ANSWER;
packet.arg = rarg;
packet.pid = rpacket->pid;
ret = ihk_ikc_send(syscall_channel, &packet, 0);
if (ret < 0) {