#include "edac_core.h"
#include "edac_module.h"
-/* lock to memory controller's control array 'edac_device_list' */
+/* lock for the list: 'edac_device_list', manipulation of this list
+ * is protected by the 'device_ctls_mutex' lock
+ */
static DEFINE_MUTEX(device_ctls_mutex);
static struct list_head edac_device_list = LIST_HEAD_INIT(edac_device_list);
/*
* edac_device_workq_function
* performs the operation scheduled by a workq request
+ *
+ * this workq is embedded within an edac_device_ctl_info
+ * structure, that needs to be polled for possible error events.
+ *
+ * This operation is to acquire the list mutex lock
+ * (thus preventing insertation or deletion)
+ * and then call the device's poll function IFF this device is
+ * running polled and there is a poll function defined.
*/
static void edac_device_workq_function(struct work_struct *work_req)
{
mutex_unlock(&device_ctls_mutex);
- /* Reschedule */
- queue_delayed_work(edac_workqueue, &edac_dev->work, edac_dev->delay);
+ /* Reschedule the workq for the next time period to start again
+ * if the number of msec is for 1 sec, then adjust to the next
+ * whole one second to save timers fireing all over the period
+ * between integral seconds
+ */
+ if (edac_dev->poll_msec == 1000)
+ queue_delayed_work(edac_workqueue, &edac_dev->work,
+ round_jiffies(edac_dev->delay));
+ else
+ queue_delayed_work(edac_workqueue, &edac_dev->work,
+ edac_dev->delay);
}
/*
{
debugf0("%s()\n", __func__);
+ /* take the arg 'msec' and set it into the control structure
+ * to used in the time period calculation
+ * then calc the number of jiffies that represents
+ */
edac_dev->poll_msec = msec;
- edac_dev->delay = msecs_to_jiffies(msec); /* Calc delay jiffies */
+ edac_dev->delay = msecs_to_jiffies(msec);
INIT_DELAYED_WORK(&edac_dev->work, edac_device_workq_function);
- queue_delayed_work(edac_workqueue, &edac_dev->work, edac_dev->delay);
+
+ /* optimize here for the 1 second case, which will be normal value, to
+ * fire ON the 1 second time event. This helps reduce all sorts of
+ * timers firing on sub-second basis, while they are happy
+ * to fire together on the 1 second exactly
+ */
+ if (edac_dev->poll_msec == 1000)
+ queue_delayed_work(edac_workqueue, &edac_dev->work,
+ round_jiffies(edac_dev->delay));
+ else
+ queue_delayed_work(edac_workqueue, &edac_dev->work,
+ edac_dev->delay);
}
/*
/*
* edac_device_reset_delay_period
+ *
+ * need to stop any outstanding workq queued up at this time
+ * because we will be resetting the sleep time.
+ * Then restart the workq on the new delay
*/
-
void edac_device_reset_delay_period(struct edac_device_ctl_info *edac_dev,
unsigned long value)
{
- mutex_lock(&device_ctls_mutex);
-
- /* cancel the current workq request */
+ /* cancel the current workq request, without the mutex lock */
edac_device_workq_teardown(edac_dev);
+ /* acquire the mutex before doing the workq setup */
+ mutex_lock(&device_ctls_mutex);
+
/* restart the workq request, with new delay value */
edac_device_workq_setup(edac_dev, value);
mutex_lock(&mem_ctls_mutex);
+ /* if this control struct has movd to offline state, we are done */
+ if (mci->op_state == OP_OFFLINE) {
+ mutex_unlock(&mem_ctls_mutex);
+ return;
+ }
+
/* Only poll controllers that are running polled and have a check */
if (edac_mc_assert_error_check_and_clear() && (mci->edac_check != NULL))
mci->edac_check(mci);
* edac_mc_workq_setup
* initialize a workq item for this mci
* passing in the new delay period in msec
+ *
+ * locking model:
+ *
+ * called with the mem_ctls_mutex held
*/
-void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec)
+static void edac_mc_workq_setup(struct mem_ctl_info *mci, unsigned msec)
{
debugf0("%s()\n", __func__);
+ /* if this instance is not in the POLL state, then simply return */
+ if (mci->op_state != OP_RUNNING_POLL)
+ return;
+
INIT_DELAYED_WORK(&mci->work, edac_mc_workq_function);
queue_delayed_work(edac_workqueue, &mci->work, msecs_to_jiffies(msec));
}
/*
* edac_mc_workq_teardown
* stop the workq processing on this mci
+ *
+ * locking model:
+ *
+ * called WITHOUT lock held
*/
-void edac_mc_workq_teardown(struct mem_ctl_info *mci)
+static void edac_mc_workq_teardown(struct mem_ctl_info *mci)
{
int status;
- status = cancel_delayed_work(&mci->work);
- if (status == 0) {
- /* workq instance might be running, wait for it */
- flush_workqueue(edac_workqueue);
+ /* if not running POLL, leave now */
+ if (mci->op_state == OP_RUNNING_POLL) {
+ status = cancel_delayed_work(&mci->work);
+ if (status == 0) {
+ debugf0("%s() not canceled, flush the queue\n",
+ __func__);
+
+ /* workq instance might be running, wait for it */
+ flush_workqueue(edac_workqueue);
+ }
}
}
/*
* edac_reset_delay_period
*/
-
-void edac_reset_delay_period(struct mem_ctl_info *mci, unsigned long value)
+static void edac_reset_delay_period(struct mem_ctl_info *mci, unsigned long value)
{
- mutex_lock(&mem_ctls_mutex);
-
/* cancel the current workq request */
edac_mc_workq_teardown(mci);
+ /* lock the list of devices for the new setup */
+ mutex_lock(&mem_ctls_mutex);
+
/* restart the workq request, with new delay value */
edac_mc_workq_setup(mci, value);
/* Return 0 on success, 1 on failure.
* Before calling this function, caller must
* assign a unique value to mci->mc_idx.
+ *
+ * locking model:
+ *
+ * called with the mem_ctls_mutex lock held
*/
static int add_mc_to_global_list(struct mem_ctl_info *mci)
{
insert_before = &mc_devices;
- if (unlikely((p = find_mci_by_dev(mci->dev)) != NULL))
+ p = find_mci_by_dev(mci->dev);
+ if (unlikely(p != NULL))
goto fail0;
list_for_each(item, &mc_devices) {
}
/* Report action taken */
- edac_mc_printk(mci, KERN_INFO, "Giving out device to %s %s: DEV %s\n",
- mci->mod_name, mci->ctl_name, dev_name(mci));
+ edac_mc_printk(mci, KERN_INFO, "Giving out device to '%s' '%s':"
+ " DEV %s\n", mci->mod_name, mci->ctl_name, dev_name(mci));
mutex_unlock(&mem_ctls_mutex);
return 0;
{
struct mem_ctl_info *mci;
- debugf0("MC: %s()\n", __func__);
+ debugf0("%s()\n", __func__);
+
mutex_lock(&mem_ctls_mutex);
- if ((mci = find_mci_by_dev(dev)) == NULL) {
+ /* find the requested mci struct in the global list */
+ mci = find_mci_by_dev(dev);
+ if (mci == NULL) {
mutex_unlock(&mem_ctls_mutex);
return NULL;
}
/* marking MCI offline */
mci->op_state = OP_OFFLINE;
- /* flush workq processes */
- edac_mc_workq_teardown(mci);
-
- edac_remove_sysfs_mci_device(mci);
del_mc_from_global_list(mci);
mutex_unlock(&mem_ctls_mutex);
+
+ /* flush workq processes and remove sysfs */
+ edac_mc_workq_teardown(mci);
+ edac_remove_sysfs_mci_device(mci);
+
edac_printk(KERN_INFO, EDAC_MC,
"Removed device %d for %s %s: DEV %s\n", mci->mc_idx,
mci->mod_name, mci->ctl_name, dev_name(mci));
+
return mci;
}
EXPORT_SYMBOL_GPL(edac_mc_del_mc);
projects / linux-2.6 / commitdiff