Hello Tomas, > -----Original Message----- > From: Tomas Henzl [mailto:thenzl@xxxxxxxxxx] > Sent: Thursday, December 3, 2015 7:52 AM > To: Raghava Aditya Renukunta; JBottomley@xxxxxxxxxxxxx; linux- > scsi@xxxxxxxxxxxxxxx > Cc: Mahesh Rajashekhara; Murthy Bhat; Santosh Akula; Gana Sridaran; > aacraid@xxxxxxxxxxxxxx; Rich Bono > Subject: Re: [PATCH 01/10] aacraid: SCSI blk tag support > > On 1.12.2015 13:39, Raghava Aditya Renukunta wrote: > > From: Raghava Aditya Renukunta <raghavaaditya.renukunta@xxxxxxxx> > > > > 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. > > [....] > > > > @@ -166,6 +166,49 @@ int aac_fib_setup(struct aac_dev * dev) > > * aac_fib_alloc - allocate a fib > > * @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 > > + */ > > Can't you just make most of the initialisation below just once when the driver > starts? > > > + 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; > > For example the flags field is initialised here to '0', then > in aac_fib_send again to zero and later is 'fibptr->flags = > FIB_CONTEXT_FLAG;' > Removing part of it would help I think. > The code here is not new so, if I am right, please plan it for a next series. I will look into it and see where the code is being duplicated and will remove it, If it does not do anything new. > > > + 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 agree with Johannes, I also don't like the aac_fib_free_tag as it is. > With the aac_fib_free_tag you may add - The reason it is still there is that , future versions can use it to add something meaningful(set flags etc).I could remove it now since it serves no purpose > Reviewed-by: Tomas Henzl <thenzl@xxxxxxxxxx> Regards, Raghava Aditya -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
