diff options
Diffstat (limited to 'Documentation/padata.txt')
| -rw-r--r-- | Documentation/padata.txt | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/Documentation/padata.txt b/Documentation/padata.txt index 269d7d0d8335..93dd4e6db975 100644 --- a/Documentation/padata.txt +++ b/Documentation/padata.txt @@ -22,12 +22,15 @@ actually be done; it should be a multithreaded queue, naturally. There are functions for enabling and disabling the instance: - void padata_start(struct padata_instance *pinst); + int padata_start(struct padata_instance *pinst); void padata_stop(struct padata_instance *pinst); -These functions literally do nothing beyond setting or clearing the -"padata_start() was called" flag; if that flag is not set, other functions -will refuse to work. +These functions are setting or clearing the "PADATA_INIT" flag; +if that flag is not set, other functions will refuse to work. +padata_start returns zero on success (flag set) or -EINVAL if the +padata cpumask contains no active cpu (flag not set). +padata_stop clears the flag and blocks until the padata instance +is unused. The list of CPUs to be used can be adjusted with these functions: @@ -63,12 +66,10 @@ The submission of work is done with: The pinst and padata structures must be set up as described above; cb_cpu specifies which CPU will be used for the final callback when the work is done; it must be in the current instance's CPU mask. The return value from -padata_do_parallel() is a little strange; zero is an error return -indicating that the caller forgot the padata_start() formalities. -EBUSY -means that somebody, somewhere else is messing with the instance's CPU -mask, while -EINVAL is a complaint about cb_cpu not being in that CPU mask. -If all goes well, this function will return -EINPROGRESS, indicating that -the work is in progress. +padata_do_parallel() is zero on success, indicating that the work is in +progress. -EBUSY means that somebody, somewhere else is messing with the +instance's CPU mask, while -EINVAL is a complaint about cb_cpu not being +in that CPU mask or about a not running instance. Each task submitted to padata_do_parallel() will, in turn, be passed to exactly one call to the above-mentioned parallel() function, on one CPU, so |