From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 44D831D17D for ; Fri, 6 Apr 2018 16:24:54 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Apr 2018 07:24:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,415,1517904000"; d="scan'208";a="44008076" Received: from fmsmsx106.amr.corp.intel.com ([10.18.124.204]) by fmsmga004.fm.intel.com with ESMTP; 06 Apr 2018 07:24:51 -0700 Received: from FMSMSX110.amr.corp.intel.com (10.18.116.10) by FMSMSX106.amr.corp.intel.com (10.18.124.204) with Microsoft SMTP Server (TLS) id 14.3.319.2; Fri, 6 Apr 2018 07:24:51 -0700 Received: from shsmsx104.ccr.corp.intel.com (10.239.4.70) by fmsmsx110.amr.corp.intel.com (10.18.116.10) with Microsoft SMTP Server (TLS) id 14.3.319.2; Fri, 6 Apr 2018 07:24:50 -0700 Received: from shsmsx103.ccr.corp.intel.com ([169.254.4.241]) by SHSMSX104.ccr.corp.intel.com ([169.254.5.43]) with mapi id 14.03.0319.002; Fri, 6 Apr 2018 22:24:49 +0800 From: "Zhang, Qi Z" To: "Zhang, Qi Z" , "Guo, Jia" , "stephen@networkplumber.org" , "Richardson, Bruce" , "Yigit, Ferruh" , "Ananyev, Konstantin" , "gaetan.rivet@6wind.com" , "Wu, Jingjing" , "thomas@monjalon.net" , "motih@mellanox.com" , "Van Haaren, Harry" , "Tan, Jianfeng" CC: "jblunck@infradead.org" , "shreyansh.jain@nxp.com" , "dev@dpdk.org" , "Guo, Jia" , "Zhang, Helin" Thread-Topic: [dpdk-dev] [PATCH V19 2/4] eal: add failure handler mechanism for hot plug Thread-Index: AQHTzZY3SZ6nATbPd0y5oSY4z2MotaPzt6mwgAAO3tA= Date: Fri, 6 Apr 2018 14:24:48 +0000 Message-ID: <039ED4275CED7440929022BC67E7061153183785@SHSMSX103.ccr.corp.intel.com> References: <1522779443-1932-6-git-send-email-jia.guo@intel.com> <1523012217-31146-1-git-send-email-jia.guo@intel.com> <1523012217-31146-3-git-send-email-jia.guo@intel.com> <039ED4275CED7440929022BC67E706115318373C@SHSMSX103.ccr.corp.intel.com> In-Reply-To: <039ED4275CED7440929022BC67E706115318373C@SHSMSX103.ccr.corp.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.0.0.116 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH V19 2/4] eal: add failure handler mechanism for hot plug X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 06 Apr 2018 14:24:56 -0000 One more comment > -----Original Message----- > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Zhang, Qi Z > Sent: Friday, April 6, 2018 10:04 PM > To: Guo, Jia ; stephen@networkplumber.org; Richardson, > Bruce ; Yigit, Ferruh ; > Ananyev, Konstantin ; > gaetan.rivet@6wind.com; Wu, Jingjing ; > thomas@monjalon.net; motih@mellanox.com; Van Haaren, Harry > ; Tan, Jianfeng > Cc: jblunck@infradead.org; shreyansh.jain@nxp.com; dev@dpdk.org; Guo, Jia > ; Zhang, Helin > Subject: Re: [dpdk-dev] [PATCH V19 2/4] eal: add failure handler mechanis= m > for hot plug >=20 > Hi Jeff: >=20 > > -----Original Message----- > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jeff Guo > > Sent: Friday, April 6, 2018 6:57 PM > > To: stephen@networkplumber.org; Richardson, Bruce > > ; Yigit, Ferruh ; > > Ananyev, Konstantin ; > > gaetan.rivet@6wind.com; Wu, Jingjing ; > > thomas@monjalon.net; motih@mellanox.com; Van Haaren, Harry > > ; Tan, Jianfeng > > Cc: jblunck@infradead.org; shreyansh.jain@nxp.com; dev@dpdk.org; Guo, > > Jia ; Zhang, Helin > > Subject: [dpdk-dev] [PATCH V19 2/4] eal: add failure handler mechanism > > for hot plug > > > > This patch introduces an API (rte_dev_handle_hot_unplug) to handle > > device hot unplug event. When device be hot plug out, the device > > resource become invalid, if this resource is still be unexpected > > read/write, system will crash. The api let user register the hot > > unplug handler,=20 The description is a little bit misleading , based on current implementatio= n. it does not a function that let user "register a handler", actually It let = user to "set a recover point" when some exception (like sigbus) happen due to hot u= nplug. Maybe the function name could be changed also,=20 for example: rte_dev_set_recover_point. > when hot plug failure occur, the working thread will > > be block until the uevent mechanism successful recovery the memory and > guaranty the application keep running smoothly. > > > > Signed-off-by: Jeff Guo > > --- > > v19->18: > > add note for limitation of multiple hotplug > > --- > > doc/guides/rel_notes/release_18_05.rst | 6 ++ > > kernel/linux/igb_uio/igb_uio.c | 4 + > > lib/librte_eal/common/include/rte_dev.h | 19 +++++ > > lib/librte_eal/linuxapp/eal/eal_dev.c | 140 > > +++++++++++++++++++++++++++++++- > > lib/librte_eal/rte_eal_version.map | 1 + > > 5 files changed, 169 insertions(+), 1 deletion(-) > > > > diff --git a/doc/guides/rel_notes/release_18_05.rst > > b/doc/guides/rel_notes/release_18_05.rst > > index cb9e050..2707e73 100644 > > --- a/doc/guides/rel_notes/release_18_05.rst > > +++ b/doc/guides/rel_notes/release_18_05.rst > > @@ -70,6 +70,12 @@ New Features > > > > Linux uevent is supported as backend of this device event > > notification framework. > > > > +* **Added hot plug failure handler.** > > + > > + Added a failure handler machenism to handle hot unplug device. > > + > > + * ``rte_dev_handle_hot_unplug`` for handle hot unplug device failure= . > > + > > API Changes > > ----------- > > > > diff --git a/kernel/linux/igb_uio/igb_uio.c > > b/kernel/linux/igb_uio/igb_uio.c index 4cae4dd..293c310 100644 > > --- a/kernel/linux/igb_uio/igb_uio.c > > +++ b/kernel/linux/igb_uio/igb_uio.c > > @@ -344,6 +344,10 @@ igbuio_pci_release(struct uio_info *info, struct > > inode > > *inode) > > struct rte_uio_pci_dev *udev =3D info->priv; > > struct pci_dev *dev =3D udev->pdev; > > > > + /* check if device has been remove before release */ > > + if ((&dev->dev.kobj)->state_remove_uevent_sent =3D=3D 1) > > + return -1; > > + > > mutex_lock(&udev->lock); > > if (--udev->refcnt > 0) { > > mutex_unlock(&udev->lock); > > diff --git a/lib/librte_eal/common/include/rte_dev.h > > b/lib/librte_eal/common/include/rte_dev.h > > index a5203e7..17c446d 100644 > > --- a/lib/librte_eal/common/include/rte_dev.h > > +++ b/lib/librte_eal/common/include/rte_dev.h > > @@ -361,4 +361,23 @@ 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 > > + * > > + * It can be used to register the device signal bus handler, and save > > +the > > + * current environment for each thread, when signal bus error invoke, > > +the > > + * handler would restore the environment by long jmp to each working > > + * thread previous locate, then block the thread to waiting until the > > +memory > > + * recovery and remapping be finished, that would guaranty the system > > +not > > + * crash when the device be hot unplug. > > + * > > + * @param none > > + * @return > > + * - From a successful direct invocation, zero. > > + * - From a call of siglongjmp(), non_zero. > > + */ > > +int __rte_experimental > > +rte_dev_handle_hot_unplug(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 9478a39..84b7efc 100644 > > --- a/lib/librte_eal/linuxapp/eal/eal_dev.c > > +++ b/lib/librte_eal/linuxapp/eal/eal_dev.c > > @@ -4,6 +4,9 @@ > > > > #include > > #include > > +#include > > +#include > > +#include > > #include > > #include > > > > @@ -13,12 +16,17 @@ > > #include > > #include > > #include > > +#include > > +#include > > > > #include "eal_private.h" > > > > static struct rte_intr_handle intr_handle =3D {.fd =3D -1 }; static b= ool > > monitor_started; > > > > +pthread_mutex_t failure_recovery_lock; pthread_cond_t > > +failure_recovery_cond; > > + > > #define EAL_UEV_MSG_LEN 4096 > > #define EAL_UEV_MSG_ELEM_LEN 128 > > > > @@ -32,6 +40,22 @@ enum eal_dev_event_subsystem { > > EAL_DEV_EVENT_SUBSYSTEM_MAX > > }; > > > > +static RTE_DEFINE_PER_LCORE(sigjmp_buf, unplug_longjmp_env); > > + > > +static void sigbus_handler(int signum __rte_unused) { > > + RTE_LOG(DEBUG, EAL, "receive SIGBUS error!\n"); > > + siglongjmp(RTE_PER_LCORE(unplug_longjmp_env), 1); } > > + > > +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) > > { > > @@ -132,6 +156,31 @@ dev_uev_parse(const char *buf, struct > > rte_dev_event *event, int length) > > return 0; > > } > > > > +static int > > +dev_uev_remove_handler(struct rte_device *dev) { > > + struct rte_bus *bus =3D rte_bus_find_by_device_name(dev->name); > > + int ret; > > + > > + if (!dev) > > + return -1; > > + > > + if (bus->handle_hot_unplug) { > > + /** > > + * call bus ops to handle hot unplug. > > + */ > > + ret =3D bus->handle_hot_unplug(dev); > > + if (ret) { > > + RTE_LOG(ERR, EAL, > > + "It cannot handle hot unplug for device (%s) " > > + "on the bus.\n ", > > + dev->name); > > + return ret; > > + } > > + } > > + return 0; > > +} > > + > > static void > > dev_delayed_unregister(void *param) > > { > > @@ -146,6 +195,9 @@ 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); > > @@ -170,11 +222,87 @@ 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 =3D "pci"; > > + break; > > + default: > > + break; > > + } > > + > > + if (uevent.devname) { > > + if (uevent.type =3D=3D RTE_DEV_EVENT_REMOVE) { > > + bus =3D rte_bus_find_by_name(busname); > > + if (bus =3D=3D NULL) { > > + RTE_LOG(ERR, EAL, "Cannot find bus (%s)\n", > > + uevent.devname); > > + return; > > + } > > + dev =3D bus->find_device(NULL, cmp_dev_name, > > + uevent.devname); > > + if (dev =3D=3D NULL) { > > + RTE_LOG(ERR, EAL, > > + "Cannot find unplugged device (%s)\n", > > + uevent.devname); > > + return; > > + } > > + ret =3D dev_uev_remove_handler(dev); > > + if (ret) { > > + RTE_LOG(ERR, EAL, "Driver cannot remap the " > > + "device (%s)\n", > > + dev->name); > > + return; > > + } > > + /* wake up all the threads */ > > + pthread_cond_broadcast(&failure_recovery_cond); > > + } > > dev_callback_process(uevent.devname, uevent.type); > > + } > > } > > > > int __rte_experimental > > +rte_dev_handle_hot_unplug(void) > > +{ > > + struct sigaction act; > > + sigset_t mask; > > + int ret =3D 0; > > + > > + /* set signal handlers */ > > + memset(&act, 0x00, sizeof(struct sigaction)); > > + act.sa_handler =3D sigbus_handler; > > + sigemptyset(&act.sa_mask); > > + act.sa_flags =3D SA_RESTART; > > + sigaction(SIGBUS, &act, NULL); > > + sigemptyset(&mask); > > + sigaddset(&mask, SIGBUS); > > + pthread_sigmask(SIG_UNBLOCK, &mask, NULL); > > + > > + ret =3D sigsetjmp(RTE_PER_LCORE(unplug_longjmp_env), 1); > > + if (ret) { > > + /* > > + * Waitting for condition variable before failure recovery > > + * finish. Now the limitation is only handle one device > > + * hot plug, for multiple devices hotplug, need check if > > + * the device belong to this working thread, then directly > > + * call memory remaping, unrelated thread just keep going > > + * their work by no interrupt from hotplug. > > + * TODO: multiple device hotplug > > + */ > > + pthread_mutex_lock(&failure_recovery_lock); > > + RTE_LOG(DEBUG, EAL, "begin waiting for the failure handler.\n"); > > + pthread_cond_wait(&failure_recovery_cond, > > + &failure_recovery_lock); > > + RTE_LOG(DEBUG, EAL, > > + "come back from waiting for failure handler.\n"); > > + pthread_mutex_unlock(&failure_recovery_lock); >=20 > I think we should not assume phread_cond_wait always happen before > pthread_cond_broadcast, It is possible Sigbus just happen before remap in > udev remove handler while pthread_cond_wait happens after > pthread_cond_broadcast, then we will wait forever. >=20 > I think we need a flag to sync > For example: >=20 > pthread_mutex_lock(&failure_recovery_lock); > if ( udev_remove_handle =3D=3D 0 ) > pthread_cond_wait(&failure_recovery_cond, & failure_recovery_lock); > pthread_remove_handle =3D 0; pthread_mutex_unlock(&failure_recovery_lock)= ; >=20 > while at remove handler: > pthread_mutex_lock(&failure_recovery_lock); > pthread_remove_handle =3D 1; > pthread_cond_signel(&failure_recovery_cond); > pthread_mutex_unlock(&failure_recovery_lock); >=20 >=20 > Regards > Qi >=20 > > + } > > + > > + return ret; > > +} > > + > > + > > +int __rte_experimental > > rte_dev_event_monitor_start(void) > > { > > int ret; > > @@ -196,6 +324,12 @@ rte_dev_event_monitor_start(void) > > return -1; > > } > > > > + /* initialize mutex and condition variable > > + * to control failure recovery. > > + */ > > + pthread_mutex_init(&failure_recovery_lock, NULL); > > + pthread_cond_init(&failure_recovery_cond, NULL); > > + > > monitor_started =3D true; > > > > return 0; > > @@ -219,5 +353,9 @@ rte_dev_event_monitor_stop(void) > > close(intr_handle.fd); > > intr_handle.fd =3D -1; > > monitor_started =3D false; > > + > > + pthread_cond_destroy(&failure_recovery_cond); > > + pthread_mutex_destroy(&failure_recovery_lock); > > + > > return 0; > > } > > diff --git a/lib/librte_eal/rte_eal_version.map > > b/lib/librte_eal/rte_eal_version.map > > index fc5c62a..873ef38 100644 > > --- a/lib/librte_eal/rte_eal_version.map > > +++ b/lib/librte_eal/rte_eal_version.map > > @@ -262,5 +262,6 @@ EXPERIMENTAL { > > rte_dev_event_monitor_stop; > > rte_dev_event_callback_register; > > rte_dev_event_callback_unregister; > > + rte_dev_handle_hot_unplug; > > > > } DPDK_18.02; > > -- > > 2.7.4