Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754864AbaGHRjr (ORCPT ); Tue, 8 Jul 2014 13:39:47 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:37860 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752135AbaGHRjq (ORCPT ); Tue, 8 Jul 2014 13:39:46 -0400 Date: Tue, 8 Jul 2014 13:39:34 -0400 From: Konrad Rzeszutek Wilk To: Zoltan Kiss Cc: Wei Liu , Ian Campbell , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Subject: Re: [Xen-devel] [PATCH net-next v3] xen-netback: Adding debugfs "io_ring_qX" files Message-ID: <20140708173934.GA6597@laptop.dumpdata.com> References: <1404837194-16726-1-git-send-email-zoltan.kiss@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1404837194-16726-1-git-send-email-zoltan.kiss@citrix.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org . snip.. > typedef unsigned int pending_ring_idx_t; > #define INVALID_PENDING_RING_IDX (~0U) > @@ -224,6 +225,10 @@ struct xenvif { > struct xenvif_queue *queues; > unsigned int num_queues; /* active queues, resource allocated */ > > +#ifdef CONFIG_DEBUG_FS > + struct dentry *xenvif_dbg_root; > +#endif /* CONFIG_DEBUG_FS */ Usually those sort of comments are good when the code inside the #ifdef spans more than one page. I think you are on the safe side if you remove it :-) > + > /* Miscellaneous private stuff. */ > struct net_device *dev; > }; > @@ -297,10 +302,16 @@ static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue) > /* Callback from stack when TX packet can be released */ > void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success); > > +irqreturn_t xenvif_interrupt(int irq, void *dev_id); > + > extern bool separate_tx_rx_irq; > > extern unsigned int rx_drain_timeout_msecs; > extern unsigned int rx_drain_timeout_jiffies; > extern unsigned int xenvif_max_queues; > > +#ifdef CONFIG_DEBUG_FS > +extern struct dentry *xen_netback_dbg_root; > +#endif /* CONFIG_DEBUG_FS */ Ditto > + > #endif /* __XEN_NETBACK__COMMON_H__ */ > diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c > index 9e97c7c..ef75b45 100644 > --- a/drivers/net/xen-netback/interface.c > +++ b/drivers/net/xen-netback/interface.c > @@ -102,7 +102,7 @@ static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id) > return IRQ_HANDLED; > } > > -static irqreturn_t xenvif_interrupt(int irq, void *dev_id) > +irqreturn_t xenvif_interrupt(int irq, void *dev_id) > { > xenvif_tx_interrupt(irq, dev_id); > xenvif_rx_interrupt(irq, dev_id); > diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c > index 1844a47..77127ca 100644 > --- a/drivers/net/xen-netback/netback.c > +++ b/drivers/net/xen-netback/netback.c > @@ -1987,6 +1987,13 @@ static int __init netback_init(void) > > rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs); > > +#ifdef CONFIG_DEBUG_FS > + xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL); > + if (IS_ERR_OR_NULL(xen_netback_dbg_root)) > + pr_warn("Init of debugfs returned %ld!\n", > + PTR_ERR(xen_netback_dbg_root)); > +#endif /* CONFIG_DEBUG_FS */ > + > return 0; > > failed_init: > @@ -1997,6 +2004,10 @@ module_init(netback_init); > > static void __exit netback_fini(void) > { > +#ifdef CONFIG_DEBUG_FS > + if (!IS_ERR_OR_NULL(xen_netback_dbg_root)) > + debugfs_remove_recursive(xen_netback_dbg_root); > +#endif /* CONFIG_DEBUG_FS */ > xenvif_xenbus_fini(); > } > module_exit(netback_fini); > diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c > index 3d85acd..03f9b08 100644 > --- a/drivers/net/xen-netback/xenbus.c > +++ b/drivers/net/xen-netback/xenbus.c > @@ -44,6 +44,173 @@ static void unregister_hotplug_status_watch(struct backend_info *be); > static void set_backend_state(struct backend_info *be, > enum xenbus_state state); > > +#ifdef CONFIG_DEBUG_FS > +struct dentry *xen_netback_dbg_root = NULL; > + > +static int xenvif_read_io_ring(struct seq_file *m, void *v) > +{ > + struct xenvif_queue *queue = m->private; > + struct xen_netif_tx_back_ring *tx_ring = &queue->tx; > + struct xen_netif_rx_back_ring *rx_ring = &queue->rx; > + > + if (tx_ring->sring) { > + struct xen_netif_tx_sring *sring = tx_ring->sring; > + > + seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id, > + tx_ring->nr_ents); > + seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n", > + sring->req_prod, > + sring->req_prod - sring->rsp_prod, > + tx_ring->req_cons, > + tx_ring->req_cons - sring->rsp_prod, > + sring->req_event, > + sring->req_event - sring->rsp_prod); > + seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n", > + sring->rsp_prod, > + tx_ring->rsp_prod_pvt, > + tx_ring->rsp_prod_pvt - sring->rsp_prod, > + sring->rsp_event, > + sring->rsp_event - sring->rsp_prod); > + seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n", > + queue->pending_prod, > + queue->pending_cons, > + nr_pending_reqs(queue)); > + seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n", > + queue->dealloc_prod, > + queue->dealloc_cons, > + queue->dealloc_prod - queue->dealloc_cons); > + } > + > + if (rx_ring->sring) { > + struct xen_netif_rx_sring *sring = rx_ring->sring; > + > + seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents); > + seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n", > + sring->req_prod, > + sring->req_prod - sring->rsp_prod, > + rx_ring->req_cons, > + rx_ring->req_cons - sring->rsp_prod, > + sring->req_event, > + sring->req_event - sring->rsp_prod); > + seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n", > + sring->rsp_prod, > + rx_ring->rsp_prod_pvt, > + rx_ring->rsp_prod_pvt - sring->rsp_prod, > + sring->rsp_event, > + sring->rsp_event - sring->rsp_prod); > + } > + > + seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n" > + "Credit timer_pending: %d, credit: %lu, usec: %lu\n" > + "remaining: %lu, expires: %lu, now: %lu\n", > + queue->napi.state, queue->napi.weight, > + skb_queue_len(&queue->tx_queue), > + timer_pending(&queue->credit_timeout), > + queue->credit_bytes, > + queue->credit_usec, > + queue->remaining_credit, > + queue->credit_timeout.expires, > + jiffies); > + > + return 0; > +} > + > +#define XENVIF_KICK_STR "kick" > + > +static ssize_t > +xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count, > + loff_t *ppos) > +{ > + struct xenvif_queue *queue = > + ((struct seq_file *)filp->private_data)->private; > + int len; > + char write[sizeof(XENVIF_KICK_STR)]; > + > + /* don't allow partial writes and check the length */ > + if (*ppos != 0) > + return 0; > + if (count < sizeof(XENVIF_KICK_STR) - 1) > + return -ENOSPC; > + > + len = simple_write_to_buffer(write, > + sizeof(write), > + ppos, > + buf, > + count); > + if (len < 0) > + return len; > + > + if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1)) > + xenvif_interrupt(0, (void *)queue); > + else > + pr_warn("Unknown command to io_ring_q%d. Available: kick\n", > + queue->id); count = -EINVAL; > + return count; > +} > + > +static int xenvif_dump_open(struct inode *inode, struct file *filp) > +{ > + int ret; > + void *queue = NULL; > + > + if (inode->i_private) > + queue = inode->i_private; > + ret = single_open(filp, xenvif_read_io_ring, queue); > + filp->f_mode |= FMODE_PWRITE; > + return ret; > +} > + > +static const struct file_operations xenvif_dbg_io_ring_ops_fops = { > + .owner = THIS_MODULE, > + .open = xenvif_dump_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > + .write = xenvif_write_io_ring, > +}; > + > +static void xenvif_debugfs_addif(struct xenvif_queue *queue) > +{ > + struct dentry *pfile; > + struct xenvif *vif = queue->vif; > + int i; > + > + if (!IS_ERR_OR_NULL(xen_netback_dbg_root)) > + return; I am curious to how you tested this patch, as my reading of the code above would imply that when xen_netback_dbg_root is initialized - we won't continue within this function? That '!' should be removed I think. > + > + vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name, > + xen_netback_dbg_root); > + if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) { > + for (i = 0; i < vif->num_queues; ++i) { > + char filename[sizeof("io_ring_q") + 4]; > + > + snprintf(filename, sizeof(filename), "io_ring_q%d", i); > + pfile = debugfs_create_file(filename, > + S_IRUSR | S_IWUSR, > + vif->xenvif_dbg_root, > + &vif->queues[i], > + &xenvif_dbg_io_ring_ops_fops); > + if (IS_ERR_OR_NULL(pfile)) > + pr_warn("Creation of io_ring file returned %ld!\n", > + PTR_ERR(pfile)); > + } > + } else > + netdev_warn(vif->dev, > + "Creation of vif debugfs dir returned %ld!\n", > + PTR_ERR(vif->xenvif_dbg_root)); > +} > + > +static void xenvif_debugfs_delif(struct xenvif *vif) > +{ > + if (!IS_ERR_OR_NULL(xen_netback_dbg_root)) Here that '!' I think needs to go too. > + return; > + > + if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) > + debugfs_remove_recursive(vif->xenvif_dbg_root); > + vif->xenvif_dbg_root = NULL; > +} > +#endif /* CONFIG_DEBUG_FS */ > + > static int netback_remove(struct xenbus_device *dev) > { > struct backend_info *be = dev_get_drvdata(&dev->dev); > @@ -246,8 +413,12 @@ static void backend_create_xenvif(struct backend_info *be) > > static void backend_disconnect(struct backend_info *be) > { > - if (be->vif) > + if (be->vif) { > +#ifdef CONFIG_DEBUG_FS > + xenvif_debugfs_delif(be->vif); > +#endif /* CONFIG_DEBUG_FS */ Why don't you just leave it as it (without the #ifdef) and add an empty function for the #else CONFIG_DEBUG_FS like: #else static inline void xenvif_debugfs_addif(struct xenvif_queue *queue) {} static inline void xenvif_debugfs_delif(struct xenvif *vif) {} #endif ? > xenvif_disconnect(be->vif); > + } > } > > static void backend_connect(struct backend_info *be) > @@ -560,6 +731,9 @@ static void connect(struct backend_info *be) > be->vif->num_queues = queue_index; > goto err; > } > +#ifdef CONFIG_DEBUG_FS > + xenvif_debugfs_addif(queue); > +#endif /* CONFIG_DEBUG_FS */ Ditto. > } > > /* Initialisation completed, tell core driver the number of > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/