Hi all,
I suggest the removal of the hashing table and various other members
associated with it from the struct linear_private_data, which are used
majorly for faster searching of devices.
struct linear_private_data
{
struct linear_private_data *prev; /* earlier version */
- dev_info_t **hash_table;
- sector_t spacing;
sector_t array_sectors;
- int sector_shift; /* shift before dividing
- * by spacing
- */
dev_info_t disks[0];
};
The reason for the same being that use of sector_div, spacing and
sector_shift involves lots of computations, which can be easily
avoided and we can achieve the same in a simpler way.
Also, in an environment where we hold a restriction to have a maximum
of 27 devices. I believe that a linear search would be faster or
atleast equal in time, if you take into consider the (time taken for
computations + search) while using the hash table as well.
Other than making the code simpler, IMO, this should also help shrink
the struct linear_private_data which might further help caching as
well.
Another enhancement to this can be to add a new member "nr_devices" (
number of devices ) to struct linear_private_data and use the same to
perform a binary search for the lokkup, as we know the sectors would
always be increasing as per we move ahead with devices.
Something like,
struct linear_private_data
{
struct linear_private_data *prev; /* earlier version */
sector_t array_sectors;
int nr_devices;
dev_info_t disks[0];
};
And accordingly, which_dev( ) can use the same to make the search
faster and better.
Comments/suggestions please.
--
Regards,
Sandeep.
“To learn is to change. Education is a process that changes the learner.”
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