RE: [PATCH] Adaptec AACRAID: convert fibctx->wait_sem to completion

Salyzyn, Mark
2008-02-13T19:05:24Z

linux/completion is already included in commctrl.c, in the patch fragment it is noted two lines below the addition. Please explain in the description the need/advantages for the change from semaphore to completion.

Sincerely -- Mark Salyzyn

> -----Original Message-----
> From: Matthias Kaehlcke [mailto:matthias@kaehlcke.net]
> Sent: Wednesday, February 13, 2008 1:35 PM
> To: AACRAID; linux-scsi@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org; akpm@linux-foundation.org
> Subject: [PATCH] Adaptec AACRAID: convert fibctx->wait_sem to
> completion
>
> Adaptec AACRAID driver: The semaphore fibctx->wait_sem is used for
> signalling an event. Convert it to a completion.
>
> Signed-off-by: Matthias Kaehlcke <matthias@kaehlcke.net>
>
> --
> diff --git a/drivers/scsi/aacraid/aacraid.h
> b/drivers/scsi/aacraid/aacraid.h
> index 3195d29..eef4939 100644
> --- a/drivers/scsi/aacraid/aacraid.h
> +++ b/drivers/scsi/aacraid/aacraid.h
> @@ -717,7 +717,7 @@ struct aac_fib_context {
> u32 unique; // unique
> value representing this context
> ulong jiffies; // used for
> cleanup - dmb changed to ulong
> struct list_head next; // used to
> link context's into a linked list
> - struct semaphore wait_sem; // this is
> used to wait for the next fib to arrive.
> + struct completion compl; // this is
> used to wait for the next fib to arrive.
> int wait; // Set to
> true when thread is in WaitForSingleObject
> unsigned long count; // total
> number of FIBs on FibList
> struct list_head fib_list; // this holds
> fibs and their attachd hw_fibs
> diff --git a/drivers/scsi/aacraid/commctrl.c
> b/drivers/scsi/aacraid/commctrl.c
> index abef051..98efda6 100644
> --- a/drivers/scsi/aacraid/commctrl.c
> +++ b/drivers/scsi/aacraid/commctrl.c
> @@ -33,6 +33,7 @@
> #include <linux/types.h>
> #include <linux/pci.h>
> #include <linux/spinlock.h>
> +#include <linux/completion.h>
> #include <linux/slab.h>
> #include <linux/completion.h>
> #include <linux/dma-mapping.h>
> @@ -177,9 +178,9 @@ static int open_getadapter_fib(struct
> aac_dev * dev, void __user *arg)
> */
> fibctx->unique = (u32)((ulong)fibctx & 0xFFFFFFFF);
> /*
> - * Initialize the mutex used to wait for
> the next AIF.
> + * Initialize the completion used to
> wait for the next AIF.
> */
> - init_MUTEX_LOCKED(&fibctx->wait_sem);
> + init_completion(&fibctx->compl);
> fibctx->wait = 0;
> /*
> * Initialize the fibs and set the count
> of fibs on
> @@ -310,7 +311,7 @@ return_fib:
> ssleep(1);
> }
> if (f.wait) {
> -
> if(down_interruptible(&fibctx->wait_sem) < 0) {
> +
> if(wait_for_completion_interruptible(&fibctx->compl) < 0) {
> status = -EINTR;
> } else {
> /* Lock again and retry */
> diff --git a/drivers/scsi/aacraid/commsup.c
> b/drivers/scsi/aacraid/commsup.c
> index 81b3692..486bdb3 100644
> --- a/drivers/scsi/aacraid/commsup.c
> +++ b/drivers/scsi/aacraid/commsup.c
> @@ -1440,7 +1440,7 @@ int aac_check_health(struct aac_dev * aac)
> * Set the event to wake up the
> * thread that will waiting.
> */
> - up(&fibctx->wait_sem);
> + complete(&fibctx->compl);
> } else {
> printk(KERN_WARNING "aifd: didn't
> allocate NewFib.\n");
> kfree(fib);
> @@ -1671,7 +1671,7 @@ int aac_command_thread(void *data)
> * Set the
> event to wake up the
> * thread
> that is waiting.
> */
> - up(&fibctx->wait_sem);
> +
> complete(&fibctx->compl);
> } else {
>
> printk(KERN_WARNING "aifd: didn't allocate NewFib.\n");
> }
> --
> Matthias Kaehlcke
> Linux System Developer
> Barcelona
>
> Si deseas mantener tu libertad, debes estar preparado para
> defenderla
> (Richard Stallman)
> .''`.
> using free software / Debian GNU/Linux |
> http://debian.org : :' :
> `. `'`
> gpg --keyserver pgp.mit.edu --recv-keys 47D8E5D4 `-
>