From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Ananyev, Konstantin" Subject: Re: [PATCH V4 6/9] eal: add failure handle mechanism for hot plug Date: Fri, 29 Jun 2018 10:49:46 +0000 Message-ID: <2601191342CEEE43887BDE71AB977258C0C43A33@irsmsx105.ger.corp.intel.com> References: <1498711073-42917-1-git-send-email-jia.guo@intel.com> <1530268248-7328-1-git-send-email-jia.guo@intel.com> <1530268248-7328-7-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" Return-path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 601451B3BA for ; Fri, 29 Jun 2018 12:50:01 +0200 (CEST) In-Reply-To: <1530268248-7328-7-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 > This patch introduces a failure handler mechanism to handle device > hot plug removal event. >=20 > First register sigbus handler, once sigbus error be captured, will > check the failure address and accordingly remap the invalid memory > for the corresponding device. Bese on this mechanism, it could > guaranty the application not to be crash when hot unplug devices. >=20 > Signed-off-by: Jeff Guo > --- > v4->v3: > split patches to be small and clear. > --- > lib/librte_eal/linuxapp/eal/eal_dev.c | 88 +++++++++++++++++++++++++++++= +++++- > 1 file changed, 87 insertions(+), 1 deletion(-) >=20 > diff --git a/lib/librte_eal/linuxapp/eal/eal_dev.c b/lib/librte_eal/linux= app/eal/eal_dev.c > index 1cf6aeb..c9dddab 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 +16,24 @@ > #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; >=20 > +extern struct rte_bus_list rte_bus_list; > + > #define EAL_UEV_MSG_LEN 4096 > #define EAL_UEV_MSG_ELEM_LEN 128 >=20 > +/* spinlock for device failure process */ > +static rte_spinlock_t dev_failure_lock =3D RTE_SPINLOCK_INITIALIZER; > + > static void dev_uev_handler(__rte_unused void *param); >=20 > /* identify the system layer which reports this event. */ > @@ -33,6 +44,34 @@ enum eal_dev_event_subsystem { > EAL_DEV_EVENT_SUBSYSTEM_MAX > }; >=20 > +static void sigbus_handler(int signum __rte_unused, siginfo_t *info, > + void *ctx __rte_unused) > +{ > + int ret; > + > + RTE_LOG(DEBUG, EAL, "Thread[%d] catch SIGBUS, fault address:%p\n", > + (int)pthread_self(), info->si_addr); > + > + rte_spinlock_lock(&dev_failure_lock); > + ret =3D rte_bus_sigbus_handler(info->si_addr); > + rte_spinlock_unlock(&dev_failure_lock); > + if (!ret) > + RTE_LOG(INFO, EAL, > + "Success to handle SIGBUS error for hotplug!\n"); > + else > + rte_exit(EXIT_FAILURE, > + "A generic SIGBUS error, (rte_errno: %s)!", > + strerror(rte_errno)); > +} As I said in comments for previous versions: I think we need to distinguish why do we fail - 1) address doesn't belong to any device, 2) we failed to remap For 1) we probably need to call previous sigbus handler. > + > +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 +186,9 @@ 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; >=20 > memset(&uevent, 0, sizeof(struct rte_dev_event)); > memset(buf, 0, EAL_UEV_MSG_LEN); > @@ -171,13 +213,48 @@ 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) { > + 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; > + } > + rte_spinlock_lock(&dev_failure_lock); > + ret =3D bus->hotplug_handler(dev); > + rte_spinlock_unlock(&dev_failure_lock); Ok, but this function is executed from interrupt thread, correct? What would happen if user would do dev-detach() at the same time and dev wo= uld not be valid anymore? Shouldn't we have a lock (per bus?) that we would grab before find_device()= and release after hotplug_handler?=20 Though in that case we probably need to revisit other bus ops too. > + if (ret) { > + RTE_LOG(ERR, EAL, "Can not handle hotplug for " > + "device (%s)\n", dev->name); > + return; > + } > + } > dev_callback_process(uevent.devname, uevent.type); > + } > } >=20 > int __rte_experimental > rte_dev_event_monitor_start(void) > { > + sigset_t mask; > + struct sigaction action; > int ret; >=20 > if (monitor_started) > @@ -197,6 +274,14 @@ rte_dev_event_monitor_start(void) > return -1; > } >=20 > + /* register sigbus handler */ > + sigemptyset(&mask); > + sigaddset(&mask, SIGBUS); > + action.sa_flags =3D SA_SIGINFO; > + action.sa_mask =3D mask; > + action.sa_sigaction =3D sigbus_handler; > + sigaction(SIGBUS, &action, NULL); > + I still think we have to save (and restore at monitor_stop) previous sigbus= handler. > monitor_started =3D true; >=20 > return 0; > @@ -220,5 +305,6 @@ rte_dev_event_monitor_stop(void) > close(intr_handle.fd); > intr_handle.fd =3D -1; > monitor_started =3D false; > + > return 0; > } > -- > 2.7.4