The shared EQ pool introduced by the previous patch is grow-only, so it sits at the high-water mark of every channel count the port has ever used. After "ethtool -L ens1 combined 32" followed by "combined 4" the port keeps 32 EQs and 32 MSI-X vectors while using four:
# ethtool -L ens1 combined 4 # grep -c mana /proc/interrupts 33 Before the queue-set swap this did not happen: mana_detach() destroyed every EQ and mana_attach() created exactly num_queues of them, so the interrupt count tracked the configured channel count. Add mana_shrink_eqs() and call it from mana_free_qset(), which is the one place where a queue set has just been torn down and the live count is already known. Both callers benefit: on success the retiring set is the old one and the pool shrinks to the new count, and if mana_publish_qset() failed and rolled back, the new set is discarded and the pool shrinks back to the restored count. Shrinking is only safe there. A CQ holds the gdma_queue pointer of its parent EQ, so an EQ may only be destroyed once the set referencing it is gone. mana_free_qset() therefore takes the live port context as well, since the pool belongs to it rather than to the scratch context. While here, fix mana_create_eq_debugfs(), which stored the new dentry in a stack copy of the mana_eq rather than in apc->eqs[i]. Nothing noticed because mana_destroy_eq() removes the whole "EQs" directory recursively, but per-EQ removal is needed to shrink without leaving stale nodes behind, which would then collide when the pool grows again. Signed-off-by: Long Li <[email protected]> --- .../net/ethernet/microsoft/mana/mana_bpf.c | 4 +- drivers/net/ethernet/microsoft/mana/mana_en.c | 79 ++++++++++++++++--- .../ethernet/microsoft/mana/mana_ethtool.c | 12 +-- include/net/mana/mana.h | 3 +- 4 files changed, 78 insertions(+), 20 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_bpf.c b/drivers/net/ethernet/microsoft/mana/mana_bpf.c index 1bae4174e268f7f53b0880c5d1098cd0ef687f25..7031ecb4da2e0fd5b83aeb07aeb8d7ae56e16d65 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_bpf.c +++ b/drivers/net/ethernet/microsoft/mana/mana_bpf.c @@ -235,7 +235,7 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog, if (err) { NL_SET_ERR_MSG_MOD(extack, "XDP: Re-config failed at publish"); - mana_free_qset(scratch, &newq); + mana_free_qset(apc, scratch, &newq); /* After the cleanup above: closing destroys the EQ pool * those queues' CQs were attached to. */ @@ -244,7 +244,7 @@ static int mana_xdp_set(struct net_device *ndev, struct bpf_prog *prog, return err; } - mana_free_qset(scratch, &oldq); + mana_free_qset(apc, scratch, &oldq); mana_qset_scratch_free(scratch); } else { /* No queues to rebuild; mana_open() will size the RX buffers diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index 71cbdebc5f3f7126495b2b11f0c673955fe0f8df..0d87440fbfbee7ac5729945d101eaa0c37745fbe 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -931,11 +931,11 @@ static int mana_change_mtu(struct net_device *ndev, int new_mtu) err = mana_publish_qset(mpc, &newq, &oldq); if (err) { - mana_free_qset(scratch, &newq); + mana_free_qset(mpc, scratch, &newq); goto free_scratch; } - mana_free_qset(scratch, &oldq); + mana_free_qset(mpc, scratch, &oldq); free_scratch: /* After the caller-side cleanup above, so the EQ pool outlives the @@ -1847,6 +1847,9 @@ void mana_destroy_eq(struct mana_port_context *apc) msi = eq->eq.msix_index; mana_gd_destroy_queue(gc, eq); mana_gd_put_gic(gc, !gc->msi_sharing, msi); + apc->eqs[i].eq = NULL; + /* Freed with the parent by debugfs_remove_recursive() above. */ + apc->eqs[i].mana_eq_debugfs = NULL; } kfree(apc->eqs); @@ -1857,15 +1860,16 @@ EXPORT_SYMBOL_NS(mana_destroy_eq, "NET_MANA"); static void mana_create_eq_debugfs(struct mana_port_context *apc, int i) { - struct mana_eq eq = apc->eqs[i]; + struct mana_eq *eq = &apc->eqs[i]; char eqnum[32]; sprintf(eqnum, "eq%d", i); - eq.mana_eq_debugfs = debugfs_create_dir(eqnum, apc->mana_eqs_debugfs); - debugfs_create_u32("head", 0400, eq.mana_eq_debugfs, &eq.eq->head); - debugfs_create_u32("tail", 0400, eq.mana_eq_debugfs, &eq.eq->tail); - debugfs_create_u32("irq", 0400, eq.mana_eq_debugfs, &eq.eq->eq.irq); - debugfs_create_file("eq_dump", 0400, eq.mana_eq_debugfs, eq.eq, &mana_dbg_q_fops); + eq->mana_eq_debugfs = debugfs_create_dir(eqnum, apc->mana_eqs_debugfs); + debugfs_create_u32("head", 0400, eq->mana_eq_debugfs, &eq->eq->head); + debugfs_create_u32("tail", 0400, eq->mana_eq_debugfs, &eq->eq->tail); + debugfs_create_u32("irq", 0400, eq->mana_eq_debugfs, &eq->eq->eq.irq); + debugfs_create_file("eq_dump", 0400, eq->mana_eq_debugfs, eq->eq, + &mana_dbg_q_fops); } int mana_create_eq(struct mana_port_context *apc) @@ -1999,6 +2003,43 @@ static int mana_grow_eqs(struct mana_port_context *apc, unsigned int need) return err; } +/** + * mana_shrink_eqs - release EQs above @keep + * @apc: port context + * @keep: number of EQs the live queue set still uses + * + * Returns the MSI-X vectors of the EQs a shrink left behind. Must only be + * called once no queue set references them, i.e. after the retiring set has + * been torn down by mana_free_qset(), otherwise a live CQ would be left + * pointing at a destroyed EQ. + */ +static void mana_shrink_eqs(struct mana_port_context *apc, unsigned int keep) +{ + struct gdma_context *gc = apc->ac->gdma_dev->gdma_context; + struct gdma_queue *eq; + unsigned int msi; + unsigned int i; + + if (!apc->eqs || keep >= apc->num_eqs) + return; + + for (i = keep; i < apc->num_eqs; i++) { + eq = apc->eqs[i].eq; + if (!eq) + continue; + + debugfs_remove_recursive(apc->eqs[i].mana_eq_debugfs); + apc->eqs[i].mana_eq_debugfs = NULL; + + msi = eq->eq.msix_index; + mana_gd_destroy_queue(gc, eq); + mana_gd_put_gic(gc, !gc->msi_sharing, msi); + apc->eqs[i].eq = NULL; + } + + apc->num_eqs = keep; +} + static int mana_fence_rq(struct mana_port_context *apc, struct mana_rxq *rxq) { struct mana_fence_rq_resp resp = {}; @@ -4224,7 +4265,7 @@ void mana_qset_scratch_free(struct mana_port_context *scratch) * Every queue is built in @scratch, so the queue set currently installed on * @apc keeps serving traffic throughout. @apc is touched only to grow the * shared EQ pool, which both sets reference while they are both live. On - * error no queue is left allocated. + * error no queue is left allocated, and any EQ this call added is released. */ int mana_alloc_qset(struct mana_port_context *apc, struct mana_port_context *scratch, unsigned int num_queues, @@ -4294,6 +4335,13 @@ int mana_alloc_qset(struct mana_port_context *apc, kfree(scratch->rxqs); scratch->rxqs = NULL; out_err: + /* Give back any EQ this attempt added to the shared pool rather than + * holding its MSI-X vectors until some later teardown: the live set + * still needs only apc->num_queues of them. Safe here because this + * set's CQs have already been destroyed above. + */ + mana_shrink_eqs(apc, apc->num_queues); + netdev_err(ndev, "mana_alloc_qset(num_queues=%u) failed: %d\n", num_queues, err); return err; @@ -4655,13 +4703,15 @@ static void mana_qset_debugfs_publish(struct mana_port_context *apc) /** * mana_free_qset - tear down all queues in @qset + * @apc: live port context (owns the shared EQ pool) * @scratch: scratch context from mana_qset_scratch_alloc() * @qset: queue set to destroy (must no longer be installed on the live apc) * * Runs the existing destroyers against @scratch so the live port context * is never made to point at queues that are being freed. */ -void mana_free_qset(struct mana_port_context *scratch, struct mana_qset *qset) +void mana_free_qset(struct mana_port_context *apc, + struct mana_port_context *scratch, struct mana_qset *qset) { struct bpf_prog *retiring_prog; unsigned int retiring_queues; @@ -4776,12 +4826,19 @@ void mana_free_qset(struct mana_port_context *scratch, struct mana_qset *qset) memset(qset, 0, sizeof(*qset)); + /* This set is gone, so any EQ above the live queue count is now + * unreferenced. Release those vectors instead of holding them at the + * high-water mark. Safe here and only here: the retiring set's CQs + * have just been destroyed. + */ + mana_shrink_eqs(apc, apc->num_queues); + /* Queues built through a scratch context carry no debugfs nodes, * because both sets are alive during the swap and would collide on * the same names. The retiring set's nodes are gone now, so the * published queues can finally take those names. */ - mana_qset_debugfs_publish(netdev_priv(scratch->ndev)); + mana_qset_debugfs_publish(apc); } /* --- end of pre-allocate + swap reconfiguration path ---------------------- */ diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c index 03fe657334c49a69ebe9c2677b2b8268321a162d..a4d62ea8aec8f4aaa521af2c4fa4af6d928e9b4e 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c @@ -744,11 +744,11 @@ static int mana_set_channels(struct net_device *ndev, err = mana_publish_qset(apc, &newq, &oldq); if (err) { - mana_free_qset(scratch, &newq); + mana_free_qset(apc, scratch, &newq); goto free_scratch; } - mana_free_qset(scratch, &oldq); + mana_free_qset(apc, scratch, &oldq); free_scratch: /* After the caller-side cleanup above, so the EQ pool outlives the @@ -852,11 +852,11 @@ static int mana_set_ringparam(struct net_device *ndev, if (err) { NL_SET_ERR_MSG_FMT(extack, "failed to change ring params: %d", err); - mana_free_qset(scratch, &newq); + mana_free_qset(apc, scratch, &newq); goto free_scratch; } - mana_free_qset(scratch, &oldq); + mana_free_qset(apc, scratch, &oldq); free_scratch: /* After the caller-side cleanup above, so the EQ pool outlives the @@ -949,11 +949,11 @@ static int mana_set_priv_flags(struct net_device *ndev, u32 priv_flags) err = mana_publish_qset(apc, &newq, &oldq); if (err) { - mana_free_qset(scratch, &newq); + mana_free_qset(apc, scratch, &newq); goto free_scratch; } - mana_free_qset(scratch, &oldq); + mana_free_qset(apc, scratch, &oldq); free_scratch: /* After the caller-side cleanup above, so the EQ pool outlives the diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h index d09bf2c7cec0be06c4190caab1f0723a5c4956d6..52f1c8f9c2b968ad14c90849fd3286b2c046d1d3 100644 --- a/include/net/mana/mana.h +++ b/include/net/mana/mana.h @@ -776,7 +776,8 @@ int mana_alloc_qset(struct mana_port_context *apc, int mana_publish_qset(struct mana_port_context *apc, struct mana_qset *newq, struct mana_qset *out_old); void mana_publish_close_if_needed(struct mana_port_context *apc); -void mana_free_qset(struct mana_port_context *scratch, struct mana_qset *qset); +void mana_free_qset(struct mana_port_context *apc, + struct mana_port_context *scratch, struct mana_qset *qset); void mana_dim_change(struct mana_cq *cq, bool enable); -- 2.43.0
