From b7cb0ccbfe228933b20fb8dd775b44f8b1cf40a7 Mon Sep 17 00:00:00 2001 From: Rebecca Schultz Zavin Date: Wed, 12 Jan 2011 11:10:34 -0800 Subject: [PATCH] video: tegra: nvmap: Don't store task struct for kernel threads No need to maintain a reference to the task struct if the client is a kernel thread. In this case just set the task to NULL. Change-Id: Ica4785388932f6b298eeb0da04b78b0e1cdc3a44 Signed-off-by: Rebecca Schultz Zavin --- drivers/video/tegra/nvmap/nvmap_dev.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/video/tegra/nvmap/nvmap_dev.c b/drivers/video/tegra/nvmap/nvmap_dev.c index 7b8228a5d956..32008e21b01e 100644 --- a/drivers/video/tegra/nvmap/nvmap_dev.c +++ b/drivers/video/tegra/nvmap/nvmap_dev.c @@ -343,8 +343,11 @@ bool nvmap_shrink_carveout(struct nvmap_carveout_node *node) get_client_from_carveout_commit(node, commit); size_t size = commit->commit; struct task_struct *task = client->task; - struct signal_struct *sig = task->signal; + struct signal_struct *sig; + if (!task) + continue; + sig = task->signal; if (!task->mm || !sig) continue; if (sig->oom_adj < selected_oom_adj) @@ -526,6 +529,7 @@ struct nvmap_client *nvmap_create_client(struct nvmap_device *dev, const char *name) { struct nvmap_client *client; + struct task_struct *task; int i; if (WARN_ON(!dev)) @@ -553,7 +557,17 @@ struct nvmap_client *nvmap_create_client(struct nvmap_device *dev, } get_task_struct(current); - client->task = current; + task_lock(current); + /* 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); + task = NULL; + } else { + task = current; + } + task_unlock(current); + client->task = task; spin_lock_init(&client->ref_lock); atomic_set(&client->count, 1); @@ -850,7 +864,11 @@ static struct attribute_group heap_extra_attr_group = { static void client_stringify(struct nvmap_client *client, struct seq_file *s) { - char task_comm[sizeof(client->task->comm)]; + char task_comm[TASK_COMM_LEN]; + if (!client->task) { + seq_printf(s, "%8s %16s %8u", client->name, "kernel", 0); + return; + } get_task_comm(task_comm, client->task); seq_printf(s, "%8s %16s %8u", client->name, task_comm, client->task->pid); -- 2.34.1