Commit b8db67d4 authored by Michal Schmidt's avatar Michal Schmidt Committed by Jakub Kicinski
Browse files

qed: make 'ethtool -d' 10 times faster 



As a side effect of commit 5401c3e0 ("qed: allow sleep in
qed_mcp_trace_dump()"), 'ethtool -d' became much slower.
Almost all the time is spent collecting the "mcp_trace".
It is caused by sleeping too long in _qed_mcp_cmd_and_union.
When called with sleeping not allowed, the function delays for 10 µs
between firmware polls. But if sleeping is allowed, it sleeps for 10 ms
instead.

The sleeps in _qed_mcp_cmd_and_union are unnecessarily long.
Replace msleep with usleep_range, which allows to achieve a similar
polling interval like in the no-sleeping mode (10 - 20 µs).

The only caller, qed_mcp_cmd_and_union, can stop doing the
multiplication/division of the usecs/max_retries. The polling interval
and the number of retries do not need to be parameters at all.

On my test system, 'ethtool -d' now takes 4 seconds instead of 44.

Signed-off-by: default avatarMichal Schmidt <mschmidt@redhat.com>
Link: https://patch.msgid.link/20240930201307.330692-2-mschmidt@redhat.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4cd0bd19

drivers/net/ethernet/qlogic/qed/qed_mcp.c

+15 −21
Original line number Diff line number Diff line
@@ -459,12 +459,11 @@ static void qed_mcp_print_cpu_info(struct qed_hwfn *p_hwfn, 
static int

_qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,

		       struct qed_ptt *p_ptt,

		       struct qed_mcp_mb_params *p_mb_params,

		       u32 max_retries, u32 usecs)

		       struct qed_mcp_mb_params *p_mb_params)

{

	u32 cnt = 0, msecs = DIV_ROUND_UP(usecs, 1000);

	struct qed_mcp_cmd_elem *p_cmd_elem;

	u16 seq_num;

	u32 cnt = 0;

	int rc = 0;



	/* Wait until the mailbox is non-occupied */
@@ -488,12 +487,13 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 
		spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);



		if (QED_MB_FLAGS_IS_SET(p_mb_params, CAN_SLEEP))

			msleep(msecs);

			usleep_range(QED_MCP_RESP_ITER_US,

				     QED_MCP_RESP_ITER_US * 2);

		else

			udelay(usecs);

	} while (++cnt < max_retries);

			udelay(QED_MCP_RESP_ITER_US);

	} while (++cnt < QED_DRV_MB_MAX_RETRIES);



	if (cnt >= max_retries) {

	if (cnt >= QED_DRV_MB_MAX_RETRIES) {

		DP_NOTICE(p_hwfn,

			  "The MFW mailbox is occupied by an uncompleted command. Failed to send command 0x%08x [param 0x%08x].\n",

			  p_mb_params->cmd, p_mb_params->param);
@@ -520,9 +520,10 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 
		 */



		if (QED_MB_FLAGS_IS_SET(p_mb_params, CAN_SLEEP))

			msleep(msecs);

			usleep_range(QED_MCP_RESP_ITER_US,

				     QED_MCP_RESP_ITER_US * 2);

		else

			udelay(usecs);

			udelay(QED_MCP_RESP_ITER_US);



		spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);
@@ -536,9 +537,9 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 
			goto err;



		spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);

	} while (++cnt < max_retries);

	} while (++cnt < QED_DRV_MB_MAX_RETRIES);



	if (cnt >= max_retries) {

	if (cnt >= QED_DRV_MB_MAX_RETRIES) {

		DP_NOTICE(p_hwfn,

			  "The MFW failed to respond to command 0x%08x [param 0x%08x].\n",

			  p_mb_params->cmd, p_mb_params->param);
@@ -564,7 +565,8 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 
		   "MFW mailbox: response 0x%08x param 0x%08x [after %d.%03d ms]\n",

		   p_mb_params->mcp_resp,

		   p_mb_params->mcp_param,

		   (cnt * usecs) / 1000, (cnt * usecs) % 1000);

		   (cnt * QED_MCP_RESP_ITER_US) / 1000,

		   (cnt * QED_MCP_RESP_ITER_US) % 1000);



	/* Clear the sequence number from the MFW response */

	p_mb_params->mcp_resp &= FW_MSG_CODE_MASK;
@@ -581,8 +583,6 @@ static int qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 
				 struct qed_mcp_mb_params *p_mb_params)

{

	size_t union_data_size = sizeof(union drv_union_data);

	u32 max_retries = QED_DRV_MB_MAX_RETRIES;

	u32 usecs = QED_MCP_RESP_ITER_US;



	/* MCP not initialized */

	if (!qed_mcp_is_init(p_hwfn)) {
@@ -606,13 +606,7 @@ static int qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn, 
		return -EINVAL;

	}



	if (QED_MB_FLAGS_IS_SET(p_mb_params, CAN_SLEEP)) {

		max_retries = DIV_ROUND_UP(max_retries, 1000);

		usecs *= 1000;

	}



	return _qed_mcp_cmd_and_union(p_hwfn, p_ptt, p_mb_params, max_retries,

				      usecs);

	return _qed_mcp_cmd_and_union(p_hwfn, p_ptt, p_mb_params);

}



static int _qed_mcp_cmd(struct qed_hwfn *p_hwfn,