From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ananyev, Konstantin" Subject: Re: [PATCH v11 6/7] eal: add failure handle mechanism for hot-unplug Date: Sun, 30 Sep 2018 19:46:57 +0000 Message-ID: <2601191342CEEE43887BDE71AB9772580102FDFEB5@IRSMSX106.ger.corp.intel.com> References: <1498711073-42917-1-git-send-email-jia.guo@intel.com> <1538307003-11836-1-git-send-email-jia.guo@intel.com> <1538307003-11836-7-git-send-email-jia.guo@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: "jblunck@infradead.org" , "shreyansh.jain@nxp.com" , "dev@dpdk.org" , "Zhang, Helin" To: "Guo, Jia" , "stephen@networkplumber.org" , "Richardson, Bruce" , "Yigit, Ferruh" , "gaetan.rivet@6wind.com" , "Wu, Jingjing" , "thomas@monjalon.net" , "motih@mellanox.com" , "matan@mellanox.com" , "Van Haaren, Harry" , "Zhang, Qi Z" , "He, Shaopeng" , "Iremonger, Bernard" , "arybchenko@solarflare.com" , "Lu, Wenzhuo" , "Burakov, Anatoly" Return-path: Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by dpdk.org (Postfix) with ESMTP id B3482239 for ; Sun, 30 Sep 2018 21:47:02 +0200 (CEST) In-Reply-To: <1538307003-11836-7-git-send-email-jia.guo@intel.com> Content-Language: en-US List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Hi Jeff, >=20 > The mechanism can initially register the sigbus handler after the device > event monitor is enabled. When a sigbus event is captured, it will check > the failure address and accordingly handle the memory failure of the > corresponding device by invoke the hot-unplug handler. It could prevent > the application from crashing when a device is hot-unplugged. >=20 > By this patch, users could call below new added APIs to enable/disable > the device hotplug handle mechanism. Note that it just implement the > hot-unplug handler in these functions, the other handler of hotplug, such > as handler for hotplug binding, could be add in the future if need: > - rte_dev_hotplug_handle_enable > - rte_dev_hotplug_handle_disable >=20 > Signed-off-by: Jeff Guo > Acked-by: Shaopeng He > --- > v11->v10: > change some words and change the invoked func name. > add experimental tag > --- > doc/guides/rel_notes/release_18_08.rst | 5 + > lib/librte_eal/bsdapp/eal/eal_dev.c | 14 +++ > lib/librte_eal/common/eal_private.h | 26 +++++ > lib/librte_eal/common/include/rte_dev.h | 26 +++++ > lib/librte_eal/linuxapp/eal/eal_dev.c | 162 ++++++++++++++++++++++++++= +++++- > lib/librte_eal/rte_eal_version.map | 2 + > 6 files changed, 234 insertions(+), 1 deletion(-) >=20 > diff --git a/doc/guides/rel_notes/release_18_08.rst b/doc/guides/rel_note= s/release_18_08.rst > index 321fa84..fe0e60f 100644 > --- a/doc/guides/rel_notes/release_18_08.rst > +++ b/doc/guides/rel_notes/release_18_08.rst > @@ -117,6 +117,11 @@ New Features >=20 > Added support for chained mbufs (input and output). >=20 > +* **Added hot-unplug handle mechanism.** > + > + ``rte_dev_hotplug_handle_enable`` and ``rte_dev_hotplug_handle_disable= `` are > + for enabling or disabling hotplug handle mechanism. > + >=20 > API Changes > ----------- > diff --git a/lib/librte_eal/bsdapp/eal/eal_dev.c b/lib/librte_eal/bsdapp/= eal/eal_dev.c > index 1c6c51b..255d611 100644 > --- a/lib/librte_eal/bsdapp/eal/eal_dev.c > +++ b/lib/librte_eal/bsdapp/eal/eal_dev.c > @@ -19,3 +19,17 @@ rte_dev_event_monitor_stop(void) > RTE_LOG(ERR, EAL, "Device event is not supported for FreeBSD\n"); > return -1; > } > + > +int __rte_experimental > +rte_dev_hotplug_handle_enable(void) > +{ > + RTE_LOG(ERR, EAL, "Device event is not supported for FreeBSD\n"); > + return -1; > +} > + > +int __rte_experimental > +rte_dev_hotplug_handle_disable(void) > +{ > + RTE_LOG(ERR, EAL, "Device event is not supported for FreeBSD\n"); > + return -1; > +} > diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/= eal_private.h > index a2d1528..637f20d 100644 > --- a/lib/librte_eal/common/eal_private.h > +++ b/lib/librte_eal/common/eal_private.h > @@ -317,4 +317,30 @@ rte_devargs_layers_parse(struct rte_devargs *devargs= , > */ > int rte_bus_sigbus_handler(const void *failure_addr); >=20 > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change without prior notice > + * > + * Register the sigbus handler. > + * > + * @return > + * - On success, zero. > + * - On failure, a negative value. > + */ > +int > +rte_dev_sigbus_handler_register(void); > + > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change without prior notice > + * > + * Unregister the sigbus handler. > + * > + * @return > + * - On success, zero. > + * - On failure, a negative value. > + */ > +int > +rte_dev_sigbus_handler_unregister(void); > + > #endif /* _EAL_PRIVATE_H_ */ > diff --git a/lib/librte_eal/common/include/rte_dev.h b/lib/librte_eal/com= mon/include/rte_dev.h > index b80a805..ff580a0 100644 > --- a/lib/librte_eal/common/include/rte_dev.h > +++ b/lib/librte_eal/common/include/rte_dev.h > @@ -460,4 +460,30 @@ rte_dev_event_monitor_start(void); > int __rte_experimental > rte_dev_event_monitor_stop(void); >=20 > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change without prior notice > + * > + * Enable hotplug handling for devices. > + * > + * @return > + * - On success, zero. > + * - On failure, a negative value. > + */ > +int __rte_experimental > +rte_dev_hotplug_handle_enable(void); > + > +/** > + * @warning > + * @b EXPERIMENTAL: this API may change without prior notice > + * > + * Disable hotplug handling for devices. > + * > + * @return > + * - On success, zero. > + * - On failure, a negative value. > + */ > +int __rte_experimental > +rte_dev_hotplug_handle_disable(void); > + > #endif /* _RTE_DEV_H_ */ > diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c b/lib/librte_eal/linux= app/eal/eal_dev.c > index 1cf6aeb..14b18d8 100644 > --- a/lib/librte_eal/linuxapp/eal/eal_dev.c > +++ b/lib/librte_eal/linuxapp/eal/eal_dev.c > @@ -4,6 +4,8 @@ >=20 > #include > #include > +#include > +#include > #include > #include >=20 > @@ -14,15 +16,32 @@ > #include > #include > #include > +#include > +#include > +#include > +#include >=20 > #include "eal_private.h" >=20 > static struct rte_intr_handle intr_handle =3D {.fd =3D -1 }; > static bool monitor_started; > +static bool hotplug_handle; >=20 > #define EAL_UEV_MSG_LEN 4096 > #define EAL_UEV_MSG_ELEM_LEN 128 >=20 > +/* > + * spinlock for device hot-unplug failure handling. If it try to access = bus or > + * device, such as handle sigbus on bus or handle memory failure for dev= ice > + * just need to use this lock. It could protect the bus and the device t= o avoid > + * race condition. > + */ > +static rte_spinlock_t failure_handle_lock =3D RTE_SPINLOCK_INITIALIZER; > + > +static struct sigaction sigbus_action_old; > + > +static int sigbus_need_recover; > + > static void dev_uev_handler(__rte_unused void *param); >=20 > /* identify the system layer which reports this event. */ > @@ -33,6 +52,49 @@ enum eal_dev_event_subsystem { > EAL_DEV_EVENT_SUBSYSTEM_MAX > }; >=20 > +static void > +sigbus_action_recover(void) > +{ > + if (sigbus_need_recover) { > + sigaction(SIGBUS, &sigbus_action_old, NULL); > + sigbus_need_recover =3D 0; > + } > +} > + > +static void sigbus_handler(int signum, siginfo_t *info, > + void *ctx __rte_unused) > +{ > + int ret; > + > + RTE_LOG(INFO, EAL, "Thread[%d] catch SIGBUS, fault address:%p\n", > + (int)pthread_self(), info->si_addr); > + > + rte_spinlock_lock(&failure_handle_lock); > + ret =3D rte_bus_sigbus_handler(info->si_addr); > + rte_spinlock_unlock(&failure_handle_lock); > + if (ret =3D=3D -1) { > + rte_exit(EXIT_FAILURE, > + "Failed to handle SIGBUS for hot-unplug, " > + "(rte_errno: %s)!", strerror(rte_errno)); > + } else if (ret =3D=3D 1) { > + if (sigbus_action_old.sa_handler) > + (*(sigbus_action_old.sa_handler))(signum); > + else > + rte_exit(EXIT_FAILURE, > + "Failed to handle generic SIGBUS!"); > + } > + > + RTE_LOG(INFO, EAL, "Success to handle SIGBUS for hot-unplug!\n"); > +} > + > +static int cmp_dev_name(const struct rte_device *dev, > + const void *_name) > +{ > + const char *name =3D _name; > + > + return strcmp(dev->name, name); > +} > + > static int > dev_uev_socket_fd_create(void) > { > @@ -147,6 +209,9 @@ dev_uev_handler(__rte_unused void *param) > struct rte_dev_event uevent; > int ret; > char buf[EAL_UEV_MSG_LEN]; > + struct rte_bus *bus; > + struct rte_device *dev; > + const char *busname =3D ""; >=20 > memset(&uevent, 0, sizeof(struct rte_dev_event)); > memset(buf, 0, EAL_UEV_MSG_LEN); > @@ -171,8 +236,43 @@ dev_uev_handler(__rte_unused void *param) > RTE_LOG(DEBUG, EAL, "receive uevent(name:%s, type:%d, subsystem:%d)\n", > uevent.devname, uevent.type, uevent.subsystem); >=20 > - if (uevent.devname) > + switch (uevent.subsystem) { > + case EAL_DEV_EVENT_SUBSYSTEM_PCI: > + case EAL_DEV_EVENT_SUBSYSTEM_UIO: > + busname =3D "pci"; > + break; > + default: > + break; > + } > + > + if (uevent.devname) { > + if (uevent.type =3D=3D RTE_DEV_EVENT_REMOVE && hotplug_handle) { > + rte_spinlock_lock(&failure_handle_lock); > + bus =3D rte_bus_find_by_name(busname); > + if (bus =3D=3D NULL) { > + RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n", > + busname); > + return; > + } > + > + dev =3D bus->find_device(NULL, cmp_dev_name, > + uevent.devname); > + if (dev =3D=3D NULL) { > + RTE_LOG(ERR, EAL, "Cannot find device (%s) on " > + "bus (%s)\n", uevent.devname, busname); > + return; > + } > + > + ret =3D bus->hot_unplug_handler(dev); > + rte_spinlock_unlock(&failure_handle_lock); > + if (ret) { > + RTE_LOG(ERR, EAL, "Can not handle hot-unplug " > + "for device (%s)\n", dev->name); > + return; > + } > + } > dev_callback_process(uevent.devname, uevent.type); > + } > } >=20 > int __rte_experimental > @@ -220,5 +320,65 @@ rte_dev_event_monitor_stop(void) > close(intr_handle.fd); > intr_handle.fd =3D -1; > monitor_started =3D false; > + > return 0; > } > + > +int __rte_experimental > +rte_dev_sigbus_handler_register(void) > +{ > + sigset_t mask; > + struct sigaction action; > + > + rte_errno =3D 0; > + Shouldn't you call sigaction only if sigbus_need_recover =3D=3D 0? > + sigemptyset(&mask); > + sigaddset(&mask, SIGBUS); > + action.sa_flags =3D SA_SIGINFO; > + action.sa_mask =3D mask; > + action.sa_sigaction =3D sigbus_handler; > + sigbus_need_recover =3D !sigaction(SIGBUS, &action, &sigbus_action_old)= ; > + > + return rte_errno; > +} > + > +int __rte_experimental > +rte_dev_sigbus_handler_unregister(void) > +{ > + rte_errno =3D 0; > + sigbus_need_recover =3D 1; Hmm, why to set sugbus_need_recover to 1 here? If user called rte_dev_sigbus_handler_register() before, and it was success= ful, it already would be 1. In other cases, you probably don't have to do anything. Konstantin > + > + sigbus_action_recover(); > + > + return rte_errno; > +} > + > +int __rte_experimental > +rte_dev_hotplug_handle_enable(void) > +{ > + int ret =3D 0; > + > + ret =3D rte_dev_sigbus_handler_register(); > + if (ret < 0) > + RTE_LOG(ERR, EAL, "fail to register sigbus handler for " > + "devices.\n"); > + > + hotplug_handle =3D true; > + > + return ret; > +} > + > +int __rte_experimental > +rte_dev_hotplug_handle_disable(void) > +{ > + int ret =3D 0; > + > + ret =3D rte_dev_sigbus_handler_unregister(); > + if (ret < 0) > + RTE_LOG(ERR, EAL, "fail to unregister sigbus handler for " > + "devices.\n"); > + > + hotplug_handle =3D false; > + > + return ret; > +} > diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_= version.map > index 73282bb..a3255aa 100644 > --- a/lib/librte_eal/rte_eal_version.map > +++ b/lib/librte_eal/rte_eal_version.map > @@ -281,6 +281,8 @@ EXPERIMENTAL { > rte_dev_event_callback_unregister; > rte_dev_event_monitor_start; > rte_dev_event_monitor_stop; > + rte_dev_hotplug_handle_enable; > + rte_dev_hotplug_handle_disable; > rte_dev_iterator_init; > rte_dev_iterator_next; > rte_devargs_add; > -- > 2.7.4