Iwai-san,
Thanks for your reviewing.
(Feb 28 2014 15:40), Takashi Iwai wrote:
+#define SWAP(tbl, m, n) \
- t = tbl[n].id; \
- tbl[n].id = tbl[m].id; \
- tbl[m].id = t; \
- t = tbl[n].dbc; \
- tbl[n].dbc = tbl[m].dbc; \
- tbl[m].dbc = t; \
- t = tbl[n].payload_size; \
- tbl[n].payload_size = tbl[m].payload_size; \
- tbl[m].payload_size = t;
Why swap() macro can't be used instead?
Because I didn't know the macro... I confirm it in kernel.h. Thank you.
+static void packet_sort(struct sort_table *tbl, unsigned int len) +{
- unsigned int i, j, k, t;
- i = 0;
- do {
for (j = i + 1; j < len; j++) {if (((tbl[i].dbc > tbl[j].dbc) &&(tbl[i].dbc - tbl[j].dbc < DBC_THRESHOLD))) {SWAP(tbl, i, j);} else if ((tbl[j].dbc > tbl[i].dbc) &&(tbl[j].dbc - tbl[i].dbc >DBC_THRESHOLD)) {for (k = i; k > 0; k--) {if ((tbl[k].dbc > tbl[j].dbc) ||(tbl[j].dbc - tbl[k].dbc >DBC_THRESHOLD)) {SWAP(tbl, j, k);}break;}}break;}i = j;- } while (i < len);
+}
You can use the standard sort() function (available in linux/sort.h).
According to /lib/sort.c, it's for heap sort.
Currently I think I cannot write this algorism as heap sort because data consist of cyclic numbers, A simple example is: [4, 5, 0, 2, 1, 3, 4, 0, 5, 1, 3, 2, 4, 0, 1, 5] After sorting, this sequence of number should be: [4, 5, 0, 1, 2, 3, 4, 5, 0, 1, 2, 3, 4, 5, 0, 1]
And we need to use stable sort algorism because there are successive elements with the same value.
If you want to see actual example, please see [PATCH 21/39]. A sequence of the last four bytes in 'CIP header 1' is data to be sort.
- /* for sorting transmitted packets */
- if (s->direction == AMDTP_IN_STREAM) {
s->remain_packets = 0;s->sort_table = kzalloc(sizeof(struct sort_table) *QUEUE_LENGTH, GFP_KERNEL);if (s->sort_table == NULL)return -ENOMEM;s->left_packets = kzalloc(amdtp_stream_get_max_payload(s) *QUEUE_LENGTH / 4, GFP_KERNEL);NULL check missing?
OK. I forgot it.
Thanks
Takashi Sakamoto o-takashi@sakamocchi.jp