forge/linux-uconsole
1
0
Fork 0
Code Issues 1 Pull requests Projects Releases Packages Wiki Activity Actions

video: tegra: nvmap: Several changes to carveout killer

Browse source 
-Add a module param to enable/disable carveout killer
-Fix race condition in code to wait for something to free memory
after firing carveout killer
-Fix the check for current so we always compare task->group_leaders

Change-Id: Ie030978827dce6b0fbbfa1db0d80e4abe59eaa51
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
This commit is contained in:
Rebecca Schultz Zavin 2011-01-24 14:16:47 -08:00
commit 82fa87e2ca
1 changed files with 60 additions and 36 deletions
Download patch file Download diff file Expand all files Collapse all files

96
drivers/video/tegra/nvmap/nvmap_dev.c
View file

@ -48,6 +48,13 @@
#define NVMAP_NUM_PTES 64
#define NVMAP_CARVEOUT_KILLER_RETRY_TIME 100 /* msecs */
#ifdef CONFIG_NVMAP_CARVEOUT_KILLER
static bool carveout_killer = true;
#else
static bool carveout_killer;
#endif
module_param(carveout_killer, bool, 0640);
struct nvmap_carveout_node {
unsigned int heap_bit;
struct nvmap_heap *carveout;
@ -324,8 +331,8 @@ static struct nvmap_client* get_client_from_carveout_commit(
carveout_commit);
}
#ifdef CONFIG_NVMAP_CARVEOUT_KILLER
static DECLARE_WAIT_QUEUE_HEAD(wait_reclaim);
static int wait_count;
bool nvmap_shrink_carveout(struct nvmap_carveout_node *node)
{
struct nvmap_carveout_commit *commit;
@ -359,6 +366,9 @@ bool nvmap_shrink_carveout(struct nvmap_carveout_node *node)
sig = task->signal;
if (!task->mm || !sig)
goto end;
/* don't try to kill current */
if (task == current->group_leader)
goto end;
/* don't try to kill higher priority tasks */
if (sig->oom_adj < current_oom_adj)
goto end;
@ -374,22 +384,22 @@ end:
task_unlock(task);
}
if (selected_task) {
wait = selected_task != current;
wait = true;
if (fatal_signal_pending(selected_task)) {
pr_warning("carveout_killer: process %d dying "
"slowly\n", selected_task->pid);
goto out;
}
pr_info("carveout_killer: killing process %d with oom_adj %d "
"to reclaim %d\n", selected_task->pid, selected_oom_adj,
selected_size);
"to reclaim %d (for process with oom_adj %d)\n",
selected_task->pid, selected_oom_adj,
selected_size, current_oom_adj);
force_sig(SIGKILL, selected_task);
}
out:
spin_unlock_irqrestore(&node->clients_lock, flags);
return wait;
}
#endif
struct nvmap_heap_block *do_nvmap_carveout_alloc(struct nvmap_client *client,
size_t len, size_t align,
@ -422,63 +432,75 @@ struct nvmap_heap_block *do_nvmap_carveout_alloc(struct nvmap_client *client,
return NULL;
}
static bool nvmap_carveout_freed(int count)
{
smp_rmb();
return count != wait_count;
}
struct nvmap_heap_block *nvmap_carveout_alloc(struct nvmap_client *client,
size_t len, size_t align,
unsigned long usage,
unsigned int prot)
{
struct nvmap_heap_block *block;
#ifdef CONFIG_NVMAP_CARVEOUT_KILLER
struct nvmap_carveout_node *co_heap;
struct nvmap_device *dev = client->dev;
int i;
unsigned long end = jiffies +
msecs_to_jiffies(NVMAP_CARVEOUT_KILLER_RETRY_TIME);
int count = 0;
DEFINE_WAIT(wait);
do {
block = do_nvmap_carveout_alloc(client, len, align, usage,
prot);
block = do_nvmap_carveout_alloc(client, len, align,
usage, prot);
if (!carveout_killer)
return block;
if (block)
return block;
if (!count++)
printk("%s: failed to allocate %u bytes, "
"firing carveout killer!\n", __func__, len);
else
printk("%s: still can't allocate %u bytes, "
"attempt %d!\n", __func__, len, count);
if (!count++) {
char task_comm[TASK_COMM_LEN];
if (client->task)
get_task_comm(task_comm, client->task);
else
task_comm[0] = 0;
pr_info("%s: failed to allocate %u bytes for "
"process %s, firing carveout "
"killer!\n", __func__, len, task_comm);
} else {
pr_info("%s: still can't allocate %u bytes, "
"attempt %d!\n", __func__, len, count);
}
/* shrink carveouts that matter and try again */
for (i = 0; i < dev->nr_carveouts; i++) {
int count;
co_heap = &dev->heaps[i];
if (!(co_heap->heap_bit & usage))
continue;
/* indicates we just delivered a sigkill to current,
or didn't find anything to kill might as well stop
trying */
count = wait_count;
/* indicates we didn't find anything to kill,
might as well stop trying */
if (!nvmap_shrink_carveout(co_heap))
return NULL;
prepare_to_wait(&wait_reclaim, &wait,
TASK_INTERRUPTIBLE);
schedule_timeout(end - jiffies);
finish_wait(&wait_reclaim, &wait);
if (time_is_after_jiffies(end))
wait_event_interruptible_timeout(wait_reclaim,
nvmap_carveout_freed(count),
end - jiffies);
}
} while (time_is_after_jiffies(end));
if (time_is_before_jiffies(end))
printk("carveout_killer: timeout expired without allocation "
"succeeding.\n");
pr_info("carveout_killer: timeout expired without "
"allocation succeeding.\n");
return NULL;
#else
block = do_nvmap_carveout_alloc(client, len, align, usage, prot);
return block;
#endif
}
/* remove a handle from the device's tree of all handles; called
@ -588,17 +610,17 @@ struct nvmap_client *nvmap_create_client(struct nvmap_device *dev,
client->carveout_commit[i].commit = 0;
}
get_task_struct(current);
task_lock(current);
get_task_struct(current->group_leader);
task_lock(current->group_leader);
/* don't bother to store task struct for kernel threads,
they can't be killed anyway */
if (current->flags & PF_KTHREAD) {
put_task_struct(current);
put_task_struct(current->group_leader);
task = NULL;
} else {
task = current;
task = current->group_leader;
}
task_unlock(current);
task_unlock(current->group_leader);
client->task = task;
spin_lock_init(&client->ref_lock);
@ -641,9 +663,11 @@ static void destroy_client(struct nvmap_client *client)
kfree(ref);
}
#ifdef CONFIG_NVMAP_CARVEOUT_KILLER
wake_up_all(&wait_reclaim);
#endif
if (carveout_killer) {
wait_count++;
smp_wmb();
wake_up_all(&wait_reclaim);
}
for (i = 0; i < client->dev->nr_carveouts; i++)
list_del(&client->carveout_commit[i].list);