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authorJens Axboe <jens.axboe@oracle.com>2008-01-24 08:52:45 +0100
committerJens Axboe <jens.axboe@oracle.com>2008-01-28 10:50:29 +0100
commitfd0928df98b9578be8a786ac0cb78a47a5e17a20 (patch)
tree70a34cf207bea1bec28e59cf0dba7d20e7f8b0f1 /include/linux/iocontext.h
parent91525300baf162e83e923b09ca286f9205e21522 (diff)
downloadlinux-linaro-stable-fd0928df98b9578be8a786ac0cb78a47a5e17a20.tar.gz
ioprio: move io priority from task_struct to io_context
This is where it belongs and then it doesn't take up space for a process that doesn't do IO. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/iocontext.h')
-rw-r--r--include/linux/iocontext.h79
1 files changed, 79 insertions, 0 deletions
diff --git a/include/linux/iocontext.h b/include/linux/iocontext.h
new file mode 100644
index 000000000000..186807ea62e2
--- /dev/null
+++ b/include/linux/iocontext.h
@@ -0,0 +1,79 @@
+#ifndef IOCONTEXT_H
+#define IOCONTEXT_H
+
+/*
+ * This is the per-process anticipatory I/O scheduler state.
+ */
+struct as_io_context {
+ spinlock_t lock;
+
+ void (*dtor)(struct as_io_context *aic); /* destructor */
+ void (*exit)(struct as_io_context *aic); /* called on task exit */
+
+ unsigned long state;
+ atomic_t nr_queued; /* queued reads & sync writes */
+ atomic_t nr_dispatched; /* number of requests gone to the drivers */
+
+ /* IO History tracking */
+ /* Thinktime */
+ unsigned long last_end_request;
+ unsigned long ttime_total;
+ unsigned long ttime_samples;
+ unsigned long ttime_mean;
+ /* Layout pattern */
+ unsigned int seek_samples;
+ sector_t last_request_pos;
+ u64 seek_total;
+ sector_t seek_mean;
+};
+
+struct cfq_queue;
+struct cfq_io_context {
+ struct rb_node rb_node;
+ void *key;
+
+ struct cfq_queue *cfqq[2];
+
+ struct io_context *ioc;
+
+ unsigned long last_end_request;
+ sector_t last_request_pos;
+
+ unsigned long ttime_total;
+ unsigned long ttime_samples;
+ unsigned long ttime_mean;
+
+ unsigned int seek_samples;
+ u64 seek_total;
+ sector_t seek_mean;
+
+ struct list_head queue_list;
+
+ void (*dtor)(struct io_context *); /* destructor */
+ void (*exit)(struct io_context *); /* called on task exit */
+};
+
+/*
+ * This is the per-process I/O subsystem state. It is refcounted and
+ * kmalloc'ed. Currently all fields are modified in process io context
+ * (apart from the atomic refcount), so require no locking.
+ */
+struct io_context {
+ atomic_t refcount;
+ struct task_struct *task;
+
+ unsigned short ioprio;
+ unsigned short ioprio_changed;
+
+ /*
+ * For request batching
+ */
+ unsigned long last_waited; /* Time last woken after wait for request */
+ int nr_batch_requests; /* Number of requests left in the batch */
+
+ struct as_io_context *aic;
+ struct rb_root cic_root;
+ void *ioc_data;
+};
+
+#endif