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 |
|---|---|---|
| basic | ||
| genksyms | ||
| kconfig | ||
| ksymoops | ||
| lxdialog | ||
| mod | ||
| package | ||
| Lindent | -rwxr-xr-x | 54 bytes |
| Makefile | -rw-r--r-- | 801 bytes |
| Makefile.build | -rw-r--r-- | 9.8 KB |
| Makefile.clean | -rw-r--r-- | 2.9 KB |
| Makefile.host | -rw-r--r-- | 5.8 KB |
| Makefile.lib | -rw-r--r-- | 9.9 KB |
| Makefile.modinst | -rw-r--r-- | 825 bytes |
| Makefile.modpost | -rw-r--r-- | 3.4 KB |
| bin2c.c | -rw-r--r-- | 702 bytes |
| binoffset.c | -rw-r--r-- | 3.9 KB |
| checkconfig.pl | -rwxr-xr-x | 1.7 KB |
| checkincludes.pl | -rwxr-xr-x | 529 bytes |
| checkstack.pl | -rw-r--r-- | 3.5 KB |
| checkversion.pl | -rwxr-xr-x | 1.9 KB |
| conmakehash.c | -rw-r--r-- | 6.0 KB |
| extract-ikconfig | -rwxr-xr-x | 1.6 KB |
| gcc-version.sh | -rw-r--r-- | 338 bytes |
| gen_initramfs_list.sh | -rw-r--r-- | 4.7 KB |
| kallsyms.c | -rw-r--r-- | 17.7 KB |
| kernel-doc | -rwxr-xr-x | 49.7 KB |
| makelst | -rwxr-xr-x | 941 bytes |
| mkcompile_h | -rwxr-xr-x | 2.1 KB |
| mkmakefile | -rw-r--r-- | 563 bytes |
| mksysmap | -rw-r--r-- | 1.3 KB |
| mkuboot.sh | -rwxr-xr-x | 293 bytes |
| mkversion | -rw-r--r-- | 74 bytes |
| namespace.pl | -rw-r--r-- | 13.1 KB |
| patch-kernel | -rwxr-xr-x | 9.7 KB |
| pnmtologo.c | -rw-r--r-- | 11.7 KB |
| reference_discarded.pl | -rw-r--r-- | 3.2 KB |
| reference_init.pl | -rw-r--r-- | 3.3 KB |
| show_delta | -rw-r--r-- | 3.0 KB |
| ver_linux | -rwxr-xr-x | 3.0 KB |
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