On Tue, 2015-12-01 at 04:39 -0800, Raghava Aditya Renukunta wrote:
> From: Raghava Aditya Renukunta <[email protected]>
>
> The method to allocate and free FIB's in the present code utilizes
> spinlocks.Multiple IO's have to wait on the spinlock to acquire or
> free fibs creating a performance bottleneck.
>
> An alternative solution would be to use block layer tags to keep track
> of the fibs allocated and freed. To this end 2 functions
> aac_fib_alloc_tag and aac_fib_free_tag were created which utilize the
> blk layer tags to plug into the Fib pool.These functions are used
> exclusively in the IO path. 8 fibs are reserved for the use of AIF
> management software and utilize the previous spinlock based
> implementations.
>
> Signed-off-by: Raghava Aditya Renukunta <[email protected]>
> ---
> drivers/scsi/aacraid/aachba.c | 35 +++++++++++++++++-------------
> drivers/scsi/aacraid/aacraid.h | 2 ++
> drivers/scsi/aacraid/commsup.c | 49 +++++++++++++++++++++++++++++++++++++++-
> --
> drivers/scsi/aacraid/dpcsup.c | 4 ++--
> drivers/scsi/aacraid/linit.c | 2 ++
> 5 files changed, 72 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
> index e4c2437..06cbab8 100644
> --- a/drivers/scsi/aacraid/aachba.c
> +++ b/drivers/scsi/aacraid/aachba.c
> @@ -323,7 +323,7 @@ static inline int aac_valid_context(struct scsi_cmnd
[...]
>
> return 0;
> }
>
> @@ -166,6 +166,49 @@ int aac_fib_setup(struct aac_dev * dev)
> * aac_fib_alloc - allocate a fib
Nitpick/Typo aac_fib_alloc_tag
> * @dev: Adapter to allocate the fib for
> *
> + * Allocate a fib from the adapter fib pool using tags
> + * from the blk layer.
> + */
> +
> +struct fib *aac_fib_alloc_tag(struct aac_dev *dev, struct scsi_cmnd *scmd)
> +{
> + struct fib *fibptr;
> +
> + fibptr = &dev->fibs[scmd->request->tag];
> + /*
> + * Set the proper node type code and node byte size
> + */
> + fibptr->type = FSAFS_NTC_FIB_CONTEXT;
> + fibptr->size = sizeof(struct fib);
> + /*
> + * Null out fields that depend on being zero at the start of
> + * each I/O
> + */
> + fibptr->hw_fib_va->header.XferState = 0;
> + fibptr->flags = 0;
> + fibptr->callback = NULL;
> + fibptr->callback_data = NULL;
> +
> + return fibptr;
> +}
> +
> +/**
> + * aac_fib_free_tag free a fib
> + * @fibptr: fib to free up
> + *
> + * Placeholder to free tag allocated fibs
> + * Does not do anything
> + */
> +
> +void aac_fib_free_tag(struct fib *fibptr)
> +{
> + (void)fibptr;
> +}
> +
I'm not sure if I like this placeholder. Sure it's a NOP and doesn't cost
anything but it's dead code. But if I'm the only one objecting here I'm fine
with it.
Reviewed-by: Johannes Thumshirn <[email protected]>
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
