https://github.com/torvalds/linux
Revision db3b5848ea6440968fcdd29b80514d0de044bb7c authored by Kiyoshi Ueda on 17 June 2005, 14:15:10 UTC, committed by Jens Axboe on 17 June 2005, 14:15:10 UTC
__cfq_get_queue(). __cfq_get_queue() finds an existing queue (struct cfq_queue) of the current process for the device and returns it. If it's not found, __cfq_get_queue() creates and returns a new one if __cfq_get_queue() is called with __GFP_WAIT flag, or __cfq_get_queue() returns NULL (this means that get_request() fails) if no __GFP_WAIT flag. On the other hand, in __make_request(), get_request() is called without __GFP_WAIT flag at the first time. Thus, the get_request() fails when there is no existing queue, typically when it's called for the first I/O request of the process to the device. Though it will be followed by get_request_wait() for general case, __make_request() will just end the I/O with an error (EWOULDBLOCK) when the request was for read-ahead. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
1 parent c374f12
Tip revision: db3b5848ea6440968fcdd29b80514d0de044bb7c authored by Kiyoshi Ueda on 17 June 2005, 14:15:10 UTC
When cfq I/O scheduler is selected, get_request() in __make_request() calls
When cfq I/O scheduler is selected, get_request() in __make_request() calls
Tip revision: db3b584
| File | Mode | Size |
|---|---|---|
| reed_solomon | ||
| zlib_deflate | ||
| zlib_inflate | ||
| Kconfig | -rw-r--r-- | 1.3 KB |
| Kconfig.debug | -rw-r--r-- | 5.6 KB |
| Makefile | -rw-r--r-- | 1.2 KB |
| bitmap.c | -rw-r--r-- | 16.2 KB |
| bust_spinlocks.c | -rw-r--r-- | 931 bytes |
| cmdline.c | -rw-r--r-- | 2.7 KB |
| crc-ccitt.c | -rw-r--r-- | 3.0 KB |
| crc32.c | -rw-r--r-- | 15.9 KB |
| crc32defs.h | -rw-r--r-- | 1.0 KB |
| ctype.c | -rw-r--r-- | 1.3 KB |
| dec_and_lock.c | -rw-r--r-- | 963 bytes |
| div64.c | -rw-r--r-- | 1.3 KB |
| dump_stack.c | -rw-r--r-- | 290 bytes |
| errno.c | -rw-r--r-- | 89 bytes |
| extable.c | -rw-r--r-- | 2.1 KB |
| find_next_bit.c | -rw-r--r-- | 1.1 KB |
| gen_crc32table.c | -rw-r--r-- | 1.8 KB |
| halfmd4.c | -rw-r--r-- | 2.0 KB |
| idr.c | -rw-r--r-- | 9.4 KB |
| inflate.c | -rw-r--r-- | 37.0 KB |
| int_sqrt.c | -rw-r--r-- | 514 bytes |
| iomap.c | -rw-r--r-- | 6.2 KB |
| kernel_lock.c | -rw-r--r-- | 5.6 KB |
| kobject.c | -rw-r--r-- | 11.1 KB |
| kobject_uevent.c | -rw-r--r-- | 8.8 KB |
| kref.c | -rw-r--r-- | 1.6 KB |
| libcrc32c.c | -rw-r--r-- | 6.5 KB |
| parser.c | -rw-r--r-- | 5.8 KB |
| prio_tree.c | -rw-r--r-- | 12.2 KB |
| radix-tree.c | -rw-r--r-- | 19.4 KB |
| rbtree.c | -rw-r--r-- | 8.9 KB |
| rwsem-spinlock.c | -rw-r--r-- | 7.5 KB |
| rwsem.c | -rw-r--r-- | 6.7 KB |
| sha1.c | -rw-r--r-- | 2.4 KB |
| sort.c | -rw-r--r-- | 2.4 KB |
| string.c | -rw-r--r-- | 12.0 KB |
| vsprintf.c | -rw-r--r-- | 18.3 KB |
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