net: dqs: make struct dql more cache efficient

With the previous change, struct dqs->stall_thrs will be in the hot path
(at queue side), even if DQS is disabled.

The other fields accessed in this function (last_obj_cnt and num_queued)
are in the first cache line, let's move this field  (stall_thrs) to the
very first cache line, since there is a hole there.

This does not change the structure size, since it moves an short (2
bytes) to 4-bytes whole in the first cache line.

This is the new structure format now:

struct dql {
	unsigned int    num_queued;
	unsigned int    last_obj_cnt;
...
	short unsigned int    stall_thrs;
	/* XXX 2 bytes hole, try to pack */
...
	/* --- cacheline 1 boundary (64 bytes) --- */
...
 	/* Longest stall detected, reported to user */
	short unsigned int         stall_max;
	/* XXX 2 bytes hole, try to pack */
};

Also, read the stall_thrs (now in the very first cache line) earlier,
together with dql->num_queued (also in the first cache line).

Suggested-by: Jakub Kicinski <[email protected]>
Suggested-by: Eric Dumazet <[email protected]>
Signed-off-by: Breno Leitao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

0 files changed, 0 insertions, 0 deletions