From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Guo Subject: Re: [PATCH v11 6/7] eal: add failure handle mechanism for hot-unplug Date: Tue, 2 Oct 2018 12:01:34 +0800 Message-ID: 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> <2601191342CEEE43887BDE71AB9772580102FDFEB5@IRSMSX106.ger.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: "jblunck@infradead.org" , "shreyansh.jain@nxp.com" , "dev@dpdk.org" , "Zhang, Helin" To: "Ananyev, Konstantin" , "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 mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 70ACC378E for ; Tue, 2 Oct 2018 06:01:58 +0200 (CEST) In-Reply-To: <2601191342CEEE43887BDE71AB9772580102FDFEB5@IRSMSX106.ger.corp.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, constantin On 10/1/2018 3:46 AM, Ananyev, Konstantin wrote: > Hi Jeff, > >> 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. >> >> 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 >> >> 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(-) >> >> diff --git a/doc/guides/rel_notes/release_18_08.rst b/doc/guides/rel_notes/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 >> >> Added support for chained mbufs (input and output). >> >> +* **Added hot-unplug handle mechanism.** >> + >> + ``rte_dev_hotplug_handle_enable`` and ``rte_dev_hotplug_handle_disable`` are >> + for enabling or disabling hotplug handle mechanism. >> + >> >> 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); >> >> +/** >> + * @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/common/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); >> >> +/** >> + * @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/linuxapp/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 @@ >> >> #include >> #include >> +#include >> +#include >> #include >> #include >> >> @@ -14,15 +16,32 @@ >> #include >> #include >> #include >> +#include >> +#include >> +#include >> +#include >> >> #include "eal_private.h" >> >> static struct rte_intr_handle intr_handle = {.fd = -1 }; >> static bool monitor_started; >> +static bool hotplug_handle; >> >> #define EAL_UEV_MSG_LEN 4096 >> #define EAL_UEV_MSG_ELEM_LEN 128 >> >> +/* >> + * 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 device >> + * just need to use this lock. It could protect the bus and the device to avoid >> + * race condition. >> + */ >> +static rte_spinlock_t failure_handle_lock = RTE_SPINLOCK_INITIALIZER; >> + >> +static struct sigaction sigbus_action_old; >> + >> +static int sigbus_need_recover; >> + >> static void dev_uev_handler(__rte_unused void *param); >> >> /* identify the system layer which reports this event. */ >> @@ -33,6 +52,49 @@ enum eal_dev_event_subsystem { >> EAL_DEV_EVENT_SUBSYSTEM_MAX >> }; >> >> +static void >> +sigbus_action_recover(void) >> +{ >> + if (sigbus_need_recover) { >> + sigaction(SIGBUS, &sigbus_action_old, NULL); >> + sigbus_need_recover = 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 = rte_bus_sigbus_handler(info->si_addr); >> + rte_spinlock_unlock(&failure_handle_lock); >> + if (ret == -1) { >> + rte_exit(EXIT_FAILURE, >> + "Failed to handle SIGBUS for hot-unplug, " >> + "(rte_errno: %s)!", strerror(rte_errno)); >> + } else if (ret == 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 = _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 = ""; >> >> 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); >> >> - if (uevent.devname) >> + switch (uevent.subsystem) { >> + case EAL_DEV_EVENT_SUBSYSTEM_PCI: >> + case EAL_DEV_EVENT_SUBSYSTEM_UIO: >> + busname = "pci"; >> + break; >> + default: >> + break; >> + } >> + >> + if (uevent.devname) { >> + if (uevent.type == RTE_DEV_EVENT_REMOVE && hotplug_handle) { >> + rte_spinlock_lock(&failure_handle_lock); >> + bus = rte_bus_find_by_name(busname); >> + if (bus == NULL) { >> + RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n", >> + busname); >> + return; >> + } >> + >> + dev = bus->find_device(NULL, cmp_dev_name, >> + uevent.devname); >> + if (dev == NULL) { >> + RTE_LOG(ERR, EAL, "Cannot find device (%s) on " >> + "bus (%s)\n", uevent.devname, busname); >> + return; >> + } >> + >> + ret = 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); >> + } >> } >> >> int __rte_experimental >> @@ -220,5 +320,65 @@ rte_dev_event_monitor_stop(void) >> close(intr_handle.fd); >> intr_handle.fd = -1; >> monitor_started = false; >> + >> return 0; >> } >> + >> +int __rte_experimental >> +rte_dev_sigbus_handler_register(void) >> +{ >> + sigset_t mask; >> + struct sigaction action; >> + >> + rte_errno = 0; >> + > Shouldn't you call sigaction only if sigbus_need_recover == 0? i guess what you mean is that the sigbus_need_recover is need check before call sigaction, because the register could be call many times, if so, i think it is make sense to check it every time. >> + sigemptyset(&mask); >> + sigaddset(&mask, SIGBUS); >> + action.sa_flags = SA_SIGINFO; >> + action.sa_mask = mask; >> + action.sa_sigaction = sigbus_handler; >> + sigbus_need_recover = !sigaction(SIGBUS, &action, &sigbus_action_old); >> + >> + return rte_errno; >> +} >> + >> +int __rte_experimental >> +rte_dev_sigbus_handler_unregister(void) >> +{ >> + rte_errno = 0; >> + sigbus_need_recover = 1; > Hmm, why to set sugbus_need_recover to 1 here? > If user called rte_dev_sigbus_handler_register() before, and it was successful, it already would be 1. > In other cases, you probably don't have to do anything. > Konstantin you are right, it should let each sigaction calling to manage this macro but no other more place, thanks. >> + >> + sigbus_action_recover(); >> + >> + return rte_errno; >> +} >> + >> +int __rte_experimental >> +rte_dev_hotplug_handle_enable(void) >> +{ >> + int ret = 0; >> + >> + ret = rte_dev_sigbus_handler_register(); >> + if (ret < 0) >> + RTE_LOG(ERR, EAL, "fail to register sigbus handler for " >> + "devices.\n"); >> + >> + hotplug_handle = true; >> + >> + return ret; >> +} >> + >> +int __rte_experimental >> +rte_dev_hotplug_handle_disable(void) >> +{ >> + int ret = 0; >> + >> + ret = rte_dev_sigbus_handler_unregister(); >> + if (ret < 0) >> + RTE_LOG(ERR, EAL, "fail to unregister sigbus handler for " >> + "devices.\n"); >> + >> + hotplug_handle = 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