[PATCH net-next 1/1] ice: Improve MSI-X vector enablement fallback logic
From: Tony Nguyen <anthony.l.nguyen@intel.com>
Date: 2021-01-14 01:58:28
From: Brett Creeley <redacted>
The current MSI-X enablement logic either tries to enable best-case
MSI-X vectors and if that fails we only support a bare-minimum set.
This is not very flexible and the current logic is broken when actually
allocating and reserving MSI-X in the driver. Fix this by improving the
fall-back logic and fixing the allocation/reservation of MSI-X when the
best-case MSI-X vectors are not received from the OS.
The new fall-back logic is described below with each [#] being an
attempt at enabling a certain number of MSI-X. If any of the steps
succeed, then return the number of MSI-X enabled from
ice_ena_msix_range(). If any of the attempts fail, then goto the next
step.
Attempt [0]: Enable the best-case scenario MSI-X vectors.
Attempt [1]: Enable MSI-X vectors with the number of pf->num_lan_msix
reduced by a factor of 2 from the previous attempt (i.e.
num_online_cpus() / 2).
Attempt [2]: Same as attempt [1], except reduce by a factor of 4.
Attempt [3]: Enable the bare-minimum MSI-X vectors.
Also, if the adjusted_base_msix ever hits the minimum required for LAN,
then just set the needed MSI-X for that feature to the minimum
(similar to attempt [3]).
To fix the allocation/reservation of MSI-X, the PF VSI needs to take
into account the pf->num_lan_msix available and only allocate up to that
many MSI-X vectors. To do this, limit the number of Tx and Rx queues
based on pf->num_lan_msix. This is done because we don't want more than
1 Tx/Rx queue per interrupt due to performance concerns. Also, limit the
number of MSI-X based on pf->num_lan_msix available.
Also, prevent users from enabling more combined queues than there are
MSI-X available via ethtool.
Fixes: 152b978a1f90 ("ice: Rework ice_ena_msix_range")
Signed-off-by: Brett Creeley <redacted>
Tested-by: Tony Brelinski <redacted>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
drivers/net/ethernet/intel/ice/ice.h | 4 +-
drivers/net/ethernet/intel/ice/ice_ethtool.c | 8 +-
drivers/net/ethernet/intel/ice/ice_lib.c | 15 +-
drivers/net/ethernet/intel/ice/ice_main.c | 161 ++++++++++---------
4 files changed, 102 insertions(+), 86 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index 56725356a17b..3cf6f2bdca41 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h@@ -68,8 +68,10 @@ #define ICE_INT_NAME_STR_LEN (IFNAMSIZ + 16) #define ICE_AQ_LEN 64 #define ICE_MBXSQ_LEN 64 -#define ICE_MIN_MSIX 2 #define ICE_FDIR_MSIX 1 +#define ICE_MIN_LAN_MSIX 1 +#define ICE_OICR_MSIX 1 +#define ICE_MIN_MSIX (ICE_MIN_LAN_MSIX + ICE_OICR_MSIX) #define ICE_NO_VSI 0xffff #define ICE_VSI_MAP_CONTIG 0 #define ICE_VSI_MAP_SCATTER 1
diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c b/drivers/net/ethernet/intel/ice/ice_ethtool.c
index 9e8e9531cd87..69c113a4de7e 100644
--- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
+++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c@@ -3258,8 +3258,8 @@ ice_set_rxfh(struct net_device *netdev, const u32 *indir, const u8 *key, */ static int ice_get_max_txq(struct ice_pf *pf) { - return min_t(int, num_online_cpus(), - pf->hw.func_caps.common_cap.num_txq); + return min3(pf->num_lan_msix, (u16)num_online_cpus(), + (u16)pf->hw.func_caps.common_cap.num_txq); } /**
@@ -3268,8 +3268,8 @@ static int ice_get_max_txq(struct ice_pf *pf) */ static int ice_get_max_rxq(struct ice_pf *pf) { - return min_t(int, num_online_cpus(), - pf->hw.func_caps.common_cap.num_rxq); + return min3(pf->num_lan_msix, (u16)num_online_cpus(), + (u16)pf->hw.func_caps.common_cap.num_rxq); } /**
diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 3df67486d42d..01da18ee17da 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c@@ -161,8 +161,10 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id) switch (vsi->type) { case ICE_VSI_PF: - vsi->alloc_txq = min_t(int, ice_get_avail_txq_count(pf), - num_online_cpus()); + /* default to 1 Tx queue per MSI-X to not hurt our performance */ + vsi->alloc_txq = min3(pf->num_lan_msix, + ice_get_avail_txq_count(pf), + (u16)num_online_cpus()); if (vsi->req_txq) { vsi->alloc_txq = vsi->req_txq; vsi->num_txq = vsi->req_txq;
@@ -174,8 +176,10 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id) if (!test_bit(ICE_FLAG_RSS_ENA, pf->flags)) { vsi->alloc_rxq = 1; } else { - vsi->alloc_rxq = min_t(int, ice_get_avail_rxq_count(pf), - num_online_cpus()); + /* default to 1 Rx queue per MSI-X to not hurt our performance */ + vsi->alloc_rxq = min3(pf->num_lan_msix, + ice_get_avail_rxq_count(pf), + (u16)num_online_cpus()); if (vsi->req_rxq) { vsi->alloc_rxq = vsi->req_rxq; vsi->num_rxq = vsi->req_rxq;
@@ -184,7 +188,8 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id) pf->num_lan_rx = vsi->alloc_rxq; - vsi->num_q_vectors = max_t(int, vsi->alloc_rxq, vsi->alloc_txq); + vsi->num_q_vectors = min_t(int, pf->num_lan_msix, + max_t(int, vsi->alloc_rxq, vsi->alloc_txq)); break; case ICE_VSI_VF: vf = &pf->vf[vsi->vf_id];
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 6e251dfffc91..040e868a0637 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c@@ -3367,95 +3367,105 @@ static int ice_init_pf(struct ice_pf *pf) return 0; } +static int ice_alloc_msix_entries(struct ice_pf *pf, u16 num_entries) +{ + u16 i; + + pf->msix_entries = devm_kcalloc(ice_pf_to_dev(pf), num_entries, + sizeof(*pf->msix_entries), GFP_KERNEL); + if (!pf->msix_entries) + return -ENOMEM; + + for (i = 0; i < num_entries; i++) + pf->msix_entries[i].entry = i; + + return 0; +} + +static void ice_free_msix_entries(struct ice_pf *pf) +{ + devm_kfree(ice_pf_to_dev(pf), pf->msix_entries); + pf->msix_entries = NULL; +} + /** - * ice_ena_msix_range - Request a range of MSIX vectors from the OS + * ice_ena_msix_range - request a range of MSI-X vectors from the OS * @pf: board private structure * - * compute the number of MSIX vectors required (v_budget) and request from - * the OS. Return the number of vectors reserved or negative on failure + * The driver first tries to enable best-case scenario MSI-X vectors. If that + * doesn't succeed then a fall-back method is employed. + * + * The fall-back logic is described below with each [#] being an attempt at + * enabling a certain number of MSI-X. If any of the steps succeed, then return + * the number of MSI-X enabled from pci_ena_msix_exact(). If any of the + * attempts fail, then goto the next step. + * + * Attempt [0]: Enable the best-case scenario MSI-X vectors. + * + * Attempt [1]: Enable MSI-X vectors with the number of pf->num_lan_msix reduced + * by a factor of 2 from the previous attempts (i.e. num_online_cpus() / 2). + * + * Attempt [2]: Same as attempt [1], except reduce both by a factor of 4. + * + * Attempt [3]: Enable the bare-minimum MSI-X vectors. + * + * Also, if the adjusted_base_msix ever hits the mimimum required for LAN, then + * just set the needed MSI-X for that feature to the minimum (similar to + * attempt [3]). */ static int ice_ena_msix_range(struct ice_pf *pf) { + int err = -ENOSPC, num_cpus, attempt, adjusted_msix_divisor = 1, needed; struct device *dev = ice_pf_to_dev(pf); - int v_left, v_actual, v_budget = 0; - int needed, err, i; - - v_left = pf->hw.func_caps.common_cap.num_msix_vectors; - - /* reserve one vector for miscellaneous handler */ - needed = 1; - if (v_left < needed) - goto no_hw_vecs_left_err; - v_budget += needed; - v_left -= needed; - - /* reserve vectors for LAN traffic */ - needed = min_t(int, num_online_cpus(), v_left); - if (v_left < needed) - goto no_hw_vecs_left_err; - pf->num_lan_msix = needed; - v_budget += needed; - v_left -= needed; - - /* reserve one vector for flow director */ - if (test_bit(ICE_FLAG_FD_ENA, pf->flags)) { - needed = ICE_FDIR_MSIX; - if (v_left < needed) - goto no_hw_vecs_left_err; - v_budget += needed; - v_left -= needed; - } - - pf->msix_entries = devm_kcalloc(dev, v_budget, - sizeof(*pf->msix_entries), GFP_KERNEL); - if (!pf->msix_entries) { - err = -ENOMEM; - goto exit_err; - } + num_cpus = num_online_cpus(); - for (i = 0; i < v_budget; i++) - pf->msix_entries[i].entry = i; +#define ICE_MAX_ENABLE_MSIX_ATTEMPTS 3 + /* make multiple passes at enabling MSI-X vectors in case there aren't + * enough available for the best-case scenario + */ + for (attempt = 0; attempt <= ICE_MAX_ENABLE_MSIX_ATTEMPTS; attempt++) { + int adjusted_base_msix = num_cpus / adjusted_msix_divisor; - /* actually reserve the vectors */ - v_actual = pci_enable_msix_range(pf->pdev, pf->msix_entries, - ICE_MIN_MSIX, v_budget); - - if (v_actual < 0) { - dev_err(dev, "unable to reserve MSI-X vectors\n"); - err = v_actual; - goto msix_err; - } - - if (v_actual < v_budget) { - dev_warn(dev, "not enough OS MSI-X vectors. requested = %d, obtained = %d\n", - v_budget, v_actual); -/* 2 vectors each for LAN and RDMA (traffic + OICR), one for flow director */ -#define ICE_MIN_LAN_VECS 2 -#define ICE_MIN_RDMA_VECS 2 -#define ICE_MIN_VECS (ICE_MIN_LAN_VECS + ICE_MIN_RDMA_VECS + 1) - - if (v_actual < ICE_MIN_LAN_VECS) { - /* error if we can't get minimum vectors */ - pci_disable_msix(pf->pdev); - err = -ERANGE; - goto msix_err; + /* attempt to enable minimum MSI-X range */ + if (attempt == ICE_MAX_ENABLE_MSIX_ATTEMPTS) { + needed = ICE_MIN_MSIX; + pf->num_lan_msix = ICE_MIN_LAN_MSIX; } else { - pf->num_lan_msix = ICE_MIN_LAN_VECS; + if (adjusted_base_msix > ICE_MIN_LAN_MSIX) + pf->num_lan_msix = adjusted_base_msix; + else + pf->num_lan_msix = ICE_MIN_LAN_MSIX; + + needed = pf->num_lan_msix + ICE_OICR_MSIX; } - } - return v_actual; + if (test_bit(ICE_FLAG_FD_ENA, pf->flags)) + needed += ICE_FDIR_MSIX; -msix_err: - devm_kfree(dev, pf->msix_entries); - goto exit_err; + err = ice_alloc_msix_entries(pf, needed); + if (err) + goto err_out; + + dev_dbg(dev, "attempting to enable %d MSI-X vectors\n", needed); + err = pci_enable_msix_exact(pf->pdev, pf->msix_entries, needed); + if (err < 0) { + ice_free_msix_entries(pf); + dev_notice(dev, "Couldn't get %d MSI-X vectors due to OS, Platform, and/or PCI-function limitations. Reducing request and retrying.", + needed); + + adjusted_msix_divisor *= 2; + } else { + if (pf->num_lan_msix != num_cpus) + dev_notice(dev, "Enabled %d MSI-X vectors for LAN traffic.\n", + pf->num_lan_msix); + + return needed; + } + } -no_hw_vecs_left_err: - dev_err(dev, "not enough device MSI-X vectors. requested = %d, available = %d\n", - needed, v_left); - err = -ERANGE; -exit_err: +err_out: + dev_err(dev, "failed to enable MSI-X vectors\n"); pf->num_lan_msix = 0; return err; }
@@ -3467,8 +3477,7 @@ static int ice_ena_msix_range(struct ice_pf *pf) static void ice_dis_msix(struct ice_pf *pf) { pci_disable_msix(pf->pdev); - devm_kfree(ice_pf_to_dev(pf), pf->msix_entries); - pf->msix_entries = NULL; + ice_free_msix_entries(pf); } /**
--
2.26.2