Messages in this thread Patch in this message | | | From | Nigel Cunningham <> | Subject | [Suspend2][ 17/32] [Suspend2] Get an io_info struct. | Date | Tue, 27 Jun 2006 08:38:08 +1000 |
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Allocate the struct used to store the details of an i/o in flight.
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
kernel/power/suspend_block_io.c | 59 +++++++++++++++++++++++++++++++++++++++ 1 files changed, 59 insertions(+), 0 deletions(-)
diff --git a/kernel/power/suspend_block_io.c b/kernel/power/suspend_block_io.c index 728df04..48a2d09 100644 --- a/kernel/power/suspend_block_io.c +++ b/kernel/power/suspend_block_io.c @@ -573,3 +573,62 @@ static void add_to_batch(struct io_info submit_batched(); } +/* + * get_io_info_struct + * + * Description: Get an I/O struct. + * Returns: Pointer to the struct prepared for use. + */ +static struct io_info *get_io_info_struct(void) +{ + unsigned long newpage = 0, flags; + struct io_info *this = NULL; + int remaining = 0; + + do { + while (atomic_read(&outstanding_io) >= MAX_OUTSTANDING_IO) + do_bio_wait(0); + + /* Can start a new I/O. Is there a free one? */ + if (!list_empty(&ioinfo_free)) { + /* Yes. Grab it. */ + spin_lock_irqsave(&ioinfo_free_lock, flags); + break; + } + + /* No. Need to allocate a new page for I/O info structs. */ + newpage = get_zeroed_page(GFP_ATOMIC); + if (!newpage) { + do_bio_wait(1); + continue; + } + + suspend_message(SUSPEND_MEMORY, SUSPEND_VERBOSE, 0, + "[NewIOPage %lx]", newpage); + infopages++; + if (infopages > maxinfopages) + maxinfopages++; + + /* Prepare the new page for use. */ + this = (struct io_info *) newpage; + remaining = PAGE_SIZE; + spin_lock_irqsave(&ioinfo_free_lock, flags); + while (remaining >= (sizeof(struct io_info))) { + list_add_tail(&this->list, &ioinfo_free); + this = (struct io_info *) (((char *) this) + + sizeof(struct io_info)); + remaining -= sizeof(struct io_info); + } + break; + } while (1); + + /* + * We have an I/O info struct. Remove it from the free list. + * It will be added to the submit or busy list later. + */ + this = list_entry(ioinfo_free.next, struct io_info, list); + list_del_init(&this->list); + spin_unlock_irqrestore(&ioinfo_free_lock, flags); + return this; +} + -- Nigel Cunningham nigel at suspend2 dot net - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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