| Message ID | 20240509204324.832846-3-jmeneghi@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
On 5/10/24 05:43, John Meneghini wrote: > From: Hannes Reinecke <hare@kernel.org> > > Add a latency-based I/O policy for multipathing. It uses the blk-nodelat > latency tracker to provide latencies for each node, and schedules > I/O on the path with the least latency for the submitting node. > > Signed-off-by: Hannes Reinecke <hare@kernel.org> > > Make this compile when CONFIG_BLK_NODE_LATENCY is not set. > Advertise the 'latency' iopolicy in modinfo. > > Signed-off-by: John Meneghini <jmeneghi@redhat.com> > --- > drivers/nvme/host/multipath.c | 63 ++++++++++++++++++++++++++++++----- > drivers/nvme/host/nvme.h | 1 + > 2 files changed, 55 insertions(+), 9 deletions(-) > > diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c > index d916a5ddf5d4..e9330bb1990b 100644 > --- a/drivers/nvme/host/multipath.c > +++ b/drivers/nvme/host/multipath.c > @@ -18,6 +18,7 @@ static const char *nvme_iopolicy_names[] = { > [NVME_IOPOLICY_NUMA] = "numa", > [NVME_IOPOLICY_RR] = "round-robin", > [NVME_IOPOLICY_QD] = "queue-depth", > + [NVME_IOPOLICY_LAT] = "latency", > }; > > static int iopolicy = NVME_IOPOLICY_NUMA; > @@ -32,6 +33,10 @@ static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp) > iopolicy = NVME_IOPOLICY_RR; > else if (!strncmp(val, "queue-depth", 11)) > iopolicy = NVME_IOPOLICY_QD; > +#ifdef CONFIG_BLK_NODE_LATENCY > + else if (!strncmp(val, "latency", 7)) > + iopolicy = NVME_IOPOLICY_LAT; > +#endif > else > return -EINVAL; > > @@ -43,10 +48,36 @@ static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp) > return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]); > } > > +static int nvme_activate_iopolicy(struct nvme_subsystem *subsys, int iopolicy) > +{ > + struct nvme_ns_head *h; > + struct nvme_ns *ns; > + bool enable = iopolicy == NVME_IOPOLICY_LAT; > + int ret = 0; > + > + mutex_lock(&subsys->lock); > + list_for_each_entry(h, &subsys->nsheads, entry) { > + list_for_each_entry_rcu(ns, &h->list, siblings) { > + if (enable) { > + ret = blk_nlat_enable(ns->disk); > + if (ret) > + break; > + } else > + blk_nlat_disable(ns->disk); Missing curly brackets for the else. > + } > + } > + mutex_unlock(&subsys->lock); > + return ret; > +} > + > module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy, > &iopolicy, 0644); > MODULE_PARM_DESC(iopolicy, > +#if defined(CONFIG_BLK_NODE_LATENCY) What is so special about the latency policy that it needs to be conditionally defined ? I missed that point. Why not drop CONFIG_BLK_NODE_LATENCY ? > + "Default multipath I/O policy; 'numa' (default) , 'round-robin', 'queue-depth' or 'latency'"); > +#else > "Default multipath I/O policy; 'numa' (default) , 'round-robin' or 'queue-depth'"); > +#endif > > void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys) > { > @@ -250,14 +281,16 @@ static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node) > { > int found_distance = INT_MAX, fallback_distance = INT_MAX, distance; > struct nvme_ns *found = NULL, *fallback = NULL, *ns; > + int iopolicy = READ_ONCE(head->subsys->iopolicy); > > list_for_each_entry_rcu(ns, &head->list, siblings) { > if (nvme_path_is_disabled(ns)) > continue; > > - if (ns->ctrl->numa_node != NUMA_NO_NODE && > - READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA) > + if (iopolicy == NVME_IOPOLICY_NUMA) > distance = node_distance(node, ns->ctrl->numa_node); > + else if (iopolicy == NVME_IOPOLICY_LAT) > + distance = blk_nlat_latency(ns->disk, node); > else > distance = LOCAL_DISTANCE; > > @@ -381,8 +414,8 @@ static inline bool nvme_path_is_optimized(struct nvme_ns *ns) > > inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) > { > - int iopolicy = READ_ONCE(head->subsys->iopolicy); > int node; > + int iopolicy = READ_ONCE(head->subsys->iopolicy); No need to move this line. > struct nvme_ns *ns; > > /* > @@ -401,8 +434,8 @@ inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) > > if (iopolicy == NVME_IOPOLICY_RR) > return nvme_round_robin_path(head, node, ns); > - > - if (unlikely(!nvme_path_is_optimized(ns))) > + if (iopolicy == NVME_IOPOLICY_LAT || > + unlikely(!nvme_path_is_optimized(ns))) > return __nvme_find_path(head, node); > return ns; > } > @@ -872,15 +905,18 @@ static ssize_t nvme_subsys_iopolicy_store(struct device *dev, > { > struct nvme_subsystem *subsys = > container_of(dev, struct nvme_subsystem, dev); > - int i; > + int i, ret; > > for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) { > if (sysfs_streq(buf, nvme_iopolicy_names[i])) { > - nvme_subsys_iopolicy_update(subsys, i); > - return count; > + ret = nvme_activate_iopolicy(subsys, i); > + if (!ret) { > + nvme_subsys_iopolicy_update(subsys, i); > + return count; > + } > + return ret; It would be nicer to have this as: if (ret) break nvme_subsys_iopolicy_update(subsys, i); return count; > } > } > - whiteline change. > return -EINVAL; And "return ret;" here with ret initialized to -EINVAL when declared. > } > SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR, > @@ -916,6 +952,15 @@ static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, > > void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid) > { > + if (!blk_nlat_init(ns->disk) && > + READ_ONCE(ns->head->subsys->iopolicy) == NVME_IOPOLICY_LAT) { > + int ret = blk_nlat_enable(ns->disk); > + > + if (unlikely(ret)) > + pr_warn("%s: Failed to enable latency tracking, error %d\n", > + ns->disk->disk_name, ret); > + } > + > if (nvme_ctrl_use_ana(ns->ctrl)) { > struct nvme_ana_group_desc desc = { > .grpid = anagrpid, > diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h > index a557b4577c01..66bf003a6c48 100644 > --- a/drivers/nvme/host/nvme.h > +++ b/drivers/nvme/host/nvme.h > @@ -411,6 +411,7 @@ enum nvme_iopolicy { > NVME_IOPOLICY_NUMA, > NVME_IOPOLICY_RR, > NVME_IOPOLICY_QD, > + NVME_IOPOLICY_LAT, > }; > > struct nvme_subsystem {
On 5/10/24 09:17, Damien Le Moal wrote: > On 5/10/24 05:43, John Meneghini wrote: >> From: Hannes Reinecke <hare@kernel.org> >> >> Add a latency-based I/O policy for multipathing. It uses the blk-nodelat >> latency tracker to provide latencies for each node, and schedules >> I/O on the path with the least latency for the submitting node. >> >> Signed-off-by: Hannes Reinecke <hare@kernel.org> >> >> Make this compile when CONFIG_BLK_NODE_LATENCY is not set. >> Advertise the 'latency' iopolicy in modinfo. >> >> Signed-off-by: John Meneghini <jmeneghi@redhat.com> >> --- >> drivers/nvme/host/multipath.c | 63 ++++++++++++++++++++++++++++++----- >> drivers/nvme/host/nvme.h | 1 + >> 2 files changed, 55 insertions(+), 9 deletions(-) >> >> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c >> index d916a5ddf5d4..e9330bb1990b 100644 >> --- a/drivers/nvme/host/multipath.c >> +++ b/drivers/nvme/host/multipath.c >> @@ -18,6 +18,7 @@ static const char *nvme_iopolicy_names[] = { >> [NVME_IOPOLICY_NUMA] = "numa", >> [NVME_IOPOLICY_RR] = "round-robin", >> [NVME_IOPOLICY_QD] = "queue-depth", >> + [NVME_IOPOLICY_LAT] = "latency", >> }; >> >> static int iopolicy = NVME_IOPOLICY_NUMA; >> @@ -32,6 +33,10 @@ static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp) >> iopolicy = NVME_IOPOLICY_RR; >> else if (!strncmp(val, "queue-depth", 11)) >> iopolicy = NVME_IOPOLICY_QD; >> +#ifdef CONFIG_BLK_NODE_LATENCY >> + else if (!strncmp(val, "latency", 7)) >> + iopolicy = NVME_IOPOLICY_LAT; >> +#endif >> else >> return -EINVAL; >> >> @@ -43,10 +48,36 @@ static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp) >> return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]); >> } >> >> +static int nvme_activate_iopolicy(struct nvme_subsystem *subsys, int iopolicy) >> +{ >> + struct nvme_ns_head *h; >> + struct nvme_ns *ns; >> + bool enable = iopolicy == NVME_IOPOLICY_LAT; >> + int ret = 0; >> + >> + mutex_lock(&subsys->lock); >> + list_for_each_entry(h, &subsys->nsheads, entry) { >> + list_for_each_entry_rcu(ns, &h->list, siblings) { >> + if (enable) { >> + ret = blk_nlat_enable(ns->disk); >> + if (ret) >> + break; >> + } else >> + blk_nlat_disable(ns->disk); > > Missing curly brackets for the else. > Ok. >> + } >> + } >> + mutex_unlock(&subsys->lock); >> + return ret; >> +} >> + >> module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy, >> &iopolicy, 0644); >> MODULE_PARM_DESC(iopolicy, >> +#if defined(CONFIG_BLK_NODE_LATENCY) > > What is so special about the latency policy that it needs to be conditionally > defined ? I missed that point. Why not drop CONFIG_BLK_NODE_LATENCY ? > The 'latency' policy is using the blk-rqos infrastructure, which in itself might not be compiled in. So we don't want the user to give a false impression here. >> + "Default multipath I/O policy; 'numa' (default) , 'round-robin', 'queue-depth' or 'latency'"); >> +#else >> "Default multipath I/O policy; 'numa' (default) , 'round-robin' or 'queue-depth'"); >> +#endif >> >> void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys) >> { >> @@ -250,14 +281,16 @@ static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node) >> { >> int found_distance = INT_MAX, fallback_distance = INT_MAX, distance; >> struct nvme_ns *found = NULL, *fallback = NULL, *ns; >> + int iopolicy = READ_ONCE(head->subsys->iopolicy); >> >> list_for_each_entry_rcu(ns, &head->list, siblings) { >> if (nvme_path_is_disabled(ns)) >> continue; >> >> - if (ns->ctrl->numa_node != NUMA_NO_NODE && >> - READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA) >> + if (iopolicy == NVME_IOPOLICY_NUMA) >> distance = node_distance(node, ns->ctrl->numa_node); >> + else if (iopolicy == NVME_IOPOLICY_LAT) >> + distance = blk_nlat_latency(ns->disk, node); >> else >> distance = LOCAL_DISTANCE; >> >> @@ -381,8 +414,8 @@ static inline bool nvme_path_is_optimized(struct nvme_ns *ns) >> >> inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) >> { >> - int iopolicy = READ_ONCE(head->subsys->iopolicy); >> int node; >> + int iopolicy = READ_ONCE(head->subsys->iopolicy); > > No need to move this line. > Sure. >> struct nvme_ns *ns; >> >> /* >> @@ -401,8 +434,8 @@ inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) >> >> if (iopolicy == NVME_IOPOLICY_RR) >> return nvme_round_robin_path(head, node, ns); >> - >> - if (unlikely(!nvme_path_is_optimized(ns))) >> + if (iopolicy == NVME_IOPOLICY_LAT || >> + unlikely(!nvme_path_is_optimized(ns))) >> return __nvme_find_path(head, node); >> return ns; >> } >> @@ -872,15 +905,18 @@ static ssize_t nvme_subsys_iopolicy_store(struct device *dev, >> { >> struct nvme_subsystem *subsys = >> container_of(dev, struct nvme_subsystem, dev); >> - int i; >> + int i, ret; >> >> for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) { >> if (sysfs_streq(buf, nvme_iopolicy_names[i])) { >> - nvme_subsys_iopolicy_update(subsys, i); >> - return count; >> + ret = nvme_activate_iopolicy(subsys, i); >> + if (!ret) { >> + nvme_subsys_iopolicy_update(subsys, i); >> + return count; >> + } >> + return ret; > > It would be nicer to have this as: > > if (ret) > break > nvme_subsys_iopolicy_update(subsys, i); > return count; > Ok. >> } >> } >> - > > whiteline change. > >> return -EINVAL; > > And "return ret;" here with ret initialized to -EINVAL when declared. > Ok. >> } >> SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR, >> @@ -916,6 +952,15 @@ static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, >> >> void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid) >> { >> + if (!blk_nlat_init(ns->disk) && >> + READ_ONCE(ns->head->subsys->iopolicy) == NVME_IOPOLICY_LAT) { >> + int ret = blk_nlat_enable(ns->disk); >> + >> + if (unlikely(ret)) >> + pr_warn("%s: Failed to enable latency tracking, error %d\n", >> + ns->disk->disk_name, ret); >> + } >> + >> if (nvme_ctrl_use_ana(ns->ctrl)) { >> struct nvme_ana_group_desc desc = { >> .grpid = anagrpid, >> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h >> index a557b4577c01..66bf003a6c48 100644 >> --- a/drivers/nvme/host/nvme.h >> +++ b/drivers/nvme/host/nvme.h >> @@ -411,6 +411,7 @@ enum nvme_iopolicy { >> NVME_IOPOLICY_NUMA, >> NVME_IOPOLICY_RR, >> NVME_IOPOLICY_QD, >> + NVME_IOPOLICY_LAT, >> }; >> >> struct nvme_subsystem { > Cheers, Hannes
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index d916a5ddf5d4..e9330bb1990b 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -18,6 +18,7 @@ static const char *nvme_iopolicy_names[] = { [NVME_IOPOLICY_NUMA] = "numa", [NVME_IOPOLICY_RR] = "round-robin", [NVME_IOPOLICY_QD] = "queue-depth", + [NVME_IOPOLICY_LAT] = "latency", }; static int iopolicy = NVME_IOPOLICY_NUMA; @@ -32,6 +33,10 @@ static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp) iopolicy = NVME_IOPOLICY_RR; else if (!strncmp(val, "queue-depth", 11)) iopolicy = NVME_IOPOLICY_QD; +#ifdef CONFIG_BLK_NODE_LATENCY + else if (!strncmp(val, "latency", 7)) + iopolicy = NVME_IOPOLICY_LAT; +#endif else return -EINVAL; @@ -43,10 +48,36 @@ static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp) return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]); } +static int nvme_activate_iopolicy(struct nvme_subsystem *subsys, int iopolicy) +{ + struct nvme_ns_head *h; + struct nvme_ns *ns; + bool enable = iopolicy == NVME_IOPOLICY_LAT; + int ret = 0; + + mutex_lock(&subsys->lock); + list_for_each_entry(h, &subsys->nsheads, entry) { + list_for_each_entry_rcu(ns, &h->list, siblings) { + if (enable) { + ret = blk_nlat_enable(ns->disk); + if (ret) + break; + } else + blk_nlat_disable(ns->disk); + } + } + mutex_unlock(&subsys->lock); + return ret; +} + module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy, &iopolicy, 0644); MODULE_PARM_DESC(iopolicy, +#if defined(CONFIG_BLK_NODE_LATENCY) + "Default multipath I/O policy; 'numa' (default) , 'round-robin', 'queue-depth' or 'latency'"); +#else "Default multipath I/O policy; 'numa' (default) , 'round-robin' or 'queue-depth'"); +#endif void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys) { @@ -250,14 +281,16 @@ static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node) { int found_distance = INT_MAX, fallback_distance = INT_MAX, distance; struct nvme_ns *found = NULL, *fallback = NULL, *ns; + int iopolicy = READ_ONCE(head->subsys->iopolicy); list_for_each_entry_rcu(ns, &head->list, siblings) { if (nvme_path_is_disabled(ns)) continue; - if (ns->ctrl->numa_node != NUMA_NO_NODE && - READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA) + if (iopolicy == NVME_IOPOLICY_NUMA) distance = node_distance(node, ns->ctrl->numa_node); + else if (iopolicy == NVME_IOPOLICY_LAT) + distance = blk_nlat_latency(ns->disk, node); else distance = LOCAL_DISTANCE; @@ -381,8 +414,8 @@ static inline bool nvme_path_is_optimized(struct nvme_ns *ns) inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) { - int iopolicy = READ_ONCE(head->subsys->iopolicy); int node; + int iopolicy = READ_ONCE(head->subsys->iopolicy); struct nvme_ns *ns; /* @@ -401,8 +434,8 @@ inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head) if (iopolicy == NVME_IOPOLICY_RR) return nvme_round_robin_path(head, node, ns); - - if (unlikely(!nvme_path_is_optimized(ns))) + if (iopolicy == NVME_IOPOLICY_LAT || + unlikely(!nvme_path_is_optimized(ns))) return __nvme_find_path(head, node); return ns; } @@ -872,15 +905,18 @@ static ssize_t nvme_subsys_iopolicy_store(struct device *dev, { struct nvme_subsystem *subsys = container_of(dev, struct nvme_subsystem, dev); - int i; + int i, ret; for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) { if (sysfs_streq(buf, nvme_iopolicy_names[i])) { - nvme_subsys_iopolicy_update(subsys, i); - return count; + ret = nvme_activate_iopolicy(subsys, i); + if (!ret) { + nvme_subsys_iopolicy_update(subsys, i); + return count; + } + return ret; } } - return -EINVAL; } SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR, @@ -916,6 +952,15 @@ static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl, void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid) { + if (!blk_nlat_init(ns->disk) && + READ_ONCE(ns->head->subsys->iopolicy) == NVME_IOPOLICY_LAT) { + int ret = blk_nlat_enable(ns->disk); + + if (unlikely(ret)) + pr_warn("%s: Failed to enable latency tracking, error %d\n", + ns->disk->disk_name, ret); + } + if (nvme_ctrl_use_ana(ns->ctrl)) { struct nvme_ana_group_desc desc = { .grpid = anagrpid, diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index a557b4577c01..66bf003a6c48 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -411,6 +411,7 @@ enum nvme_iopolicy { NVME_IOPOLICY_NUMA, NVME_IOPOLICY_RR, NVME_IOPOLICY_QD, + NVME_IOPOLICY_LAT, }; struct nvme_subsystem {