From 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 21 Feb 2023 18:24:12 -0800 Subject: Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ... --- kernel/profile.c | 501 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 501 insertions(+) create mode 100644 kernel/profile.c (limited to 'kernel/profile.c') diff --git a/kernel/profile.c b/kernel/profile.c new file mode 100644 index 000000000..8a77769bc --- /dev/null +++ b/kernel/profile.c @@ -0,0 +1,501 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/kernel/profile.c + * Simple profiling. Manages a direct-mapped profile hit count buffer, + * with configurable resolution, support for restricting the cpus on + * which profiling is done, and switching between cpu time and + * schedule() calls via kernel command line parameters passed at boot. + * + * Scheduler profiling support, Arjan van de Ven and Ingo Molnar, + * Red Hat, July 2004 + * Consolidation of architecture support code for profiling, + * Nadia Yvette Chambers, Oracle, July 2004 + * Amortized hit count accounting via per-cpu open-addressed hashtables + * to resolve timer interrupt livelocks, Nadia Yvette Chambers, + * Oracle, 2004 + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +struct profile_hit { + u32 pc, hits; +}; +#define PROFILE_GRPSHIFT 3 +#define PROFILE_GRPSZ (1 << PROFILE_GRPSHIFT) +#define NR_PROFILE_HIT (PAGE_SIZE/sizeof(struct profile_hit)) +#define NR_PROFILE_GRP (NR_PROFILE_HIT/PROFILE_GRPSZ) + +static atomic_t *prof_buffer; +static unsigned long prof_len; +static unsigned short int prof_shift; + +int prof_on __read_mostly; +EXPORT_SYMBOL_GPL(prof_on); + +static cpumask_var_t prof_cpu_mask; +#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) +static DEFINE_PER_CPU(struct profile_hit *[2], cpu_profile_hits); +static DEFINE_PER_CPU(int, cpu_profile_flip); +static DEFINE_MUTEX(profile_flip_mutex); +#endif /* CONFIG_SMP */ + +int profile_setup(char *str) +{ + static const char schedstr[] = "schedule"; + static const char sleepstr[] = "sleep"; + static const char kvmstr[] = "kvm"; + const char *select = NULL; + int par; + + if (!strncmp(str, sleepstr, strlen(sleepstr))) { +#ifdef CONFIG_SCHEDSTATS + force_schedstat_enabled(); + prof_on = SLEEP_PROFILING; + select = sleepstr; +#else + pr_warn("kernel sleep profiling requires CONFIG_SCHEDSTATS\n"); +#endif /* CONFIG_SCHEDSTATS */ + } else if (!strncmp(str, schedstr, strlen(schedstr))) { + prof_on = SCHED_PROFILING; + select = schedstr; + } else if (!strncmp(str, kvmstr, strlen(kvmstr))) { + prof_on = KVM_PROFILING; + select = kvmstr; + } else if (get_option(&str, &par)) { + prof_shift = clamp(par, 0, BITS_PER_LONG - 1); + prof_on = CPU_PROFILING; + pr_info("kernel profiling enabled (shift: %u)\n", + prof_shift); + } + + if (select) { + if (str[strlen(select)] == ',') + str += strlen(select) + 1; + if (get_option(&str, &par)) + prof_shift = clamp(par, 0, BITS_PER_LONG - 1); + pr_info("kernel %s profiling enabled (shift: %u)\n", + select, prof_shift); + } + + return 1; +} +__setup("profile=", profile_setup); + + +int __ref profile_init(void) +{ + int buffer_bytes; + if (!prof_on) + return 0; + + /* only text is profiled */ + prof_len = (_etext - _stext) >> prof_shift; + + if (!prof_len) { + pr_warn("profiling shift: %u too large\n", prof_shift); + prof_on = 0; + return -EINVAL; + } + + buffer_bytes = prof_len*sizeof(atomic_t); + + if (!alloc_cpumask_var(&prof_cpu_mask, GFP_KERNEL)) + return -ENOMEM; + + cpumask_copy(prof_cpu_mask, cpu_possible_mask); + + prof_buffer = kzalloc(buffer_bytes, GFP_KERNEL|__GFP_NOWARN); + if (prof_buffer) + return 0; + + prof_buffer = alloc_pages_exact(buffer_bytes, + GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN); + if (prof_buffer) + return 0; + + prof_buffer = vzalloc(buffer_bytes); + if (prof_buffer) + return 0; + + free_cpumask_var(prof_cpu_mask); + return -ENOMEM; +} + +#if defined(CONFIG_SMP) && defined(CONFIG_PROC_FS) +/* + * Each cpu has a pair of open-addressed hashtables for pending + * profile hits. read_profile() IPI's all cpus to request them + * to flip buffers and flushes their contents to prof_buffer itself. + * Flip requests are serialized by the profile_flip_mutex. The sole + * use of having a second hashtable is for avoiding cacheline + * contention that would otherwise happen during flushes of pending + * profile hits required for the accuracy of reported profile hits + * and so resurrect the interrupt livelock issue. + * + * The open-addressed hashtables are indexed by profile buffer slot + * and hold the number of pending hits to that profile buffer slot on + * a cpu in an entry. When the hashtable overflows, all pending hits + * are accounted to their corresponding profile buffer slots with + * atomic_add() and the hashtable emptied. As numerous pending hits + * may be accounted to a profile buffer slot in a hashtable entry, + * this amortizes a number of atomic profile buffer increments likely + * to be far larger than the number of entries in the hashtable, + * particularly given that the number of distinct profile buffer + * positions to which hits are accounted during short intervals (e.g. + * several seconds) is usually very small. Exclusion from buffer + * flipping is provided by interrupt disablement (note that for + * SCHED_PROFILING or SLEEP_PROFILING profile_hit() may be called from + * process context). + * The hash function is meant to be lightweight as opposed to strong, + * and was vaguely inspired by ppc64 firmware-supported inverted + * pagetable hash functions, but uses a full hashtable full of finite + * collision chains, not just pairs of them. + * + * -- nyc + */ +static void __profile_flip_buffers(void *unused) +{ + int cpu = smp_processor_id(); + + per_cpu(cpu_profile_flip, cpu) = !per_cpu(cpu_profile_flip, cpu); +} + +static void profile_flip_buffers(void) +{ + int i, j, cpu; + + mutex_lock(&profile_flip_mutex); + j = per_cpu(cpu_profile_flip, get_cpu()); + put_cpu(); + on_each_cpu(__profile_flip_buffers, NULL, 1); + for_each_online_cpu(cpu) { + struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[j]; + for (i = 0; i < NR_PROFILE_HIT; ++i) { + if (!hits[i].hits) { + if (hits[i].pc) + hits[i].pc = 0; + continue; + } + atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); + hits[i].hits = hits[i].pc = 0; + } + } + mutex_unlock(&profile_flip_mutex); +} + +static void profile_discard_flip_buffers(void) +{ + int i, cpu; + + mutex_lock(&profile_flip_mutex); + i = per_cpu(cpu_profile_flip, get_cpu()); + put_cpu(); + on_each_cpu(__profile_flip_buffers, NULL, 1); + for_each_online_cpu(cpu) { + struct profile_hit *hits = per_cpu(cpu_profile_hits, cpu)[i]; + memset(hits, 0, NR_PROFILE_HIT*sizeof(struct profile_hit)); + } + mutex_unlock(&profile_flip_mutex); +} + +static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) +{ + unsigned long primary, secondary, flags, pc = (unsigned long)__pc; + int i, j, cpu; + struct profile_hit *hits; + + pc = min((pc - (unsigned long)_stext) >> prof_shift, prof_len - 1); + i = primary = (pc & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; + secondary = (~(pc << 1) & (NR_PROFILE_GRP - 1)) << PROFILE_GRPSHIFT; + cpu = get_cpu(); + hits = per_cpu(cpu_profile_hits, cpu)[per_cpu(cpu_profile_flip, cpu)]; + if (!hits) { + put_cpu(); + return; + } + /* + * We buffer the global profiler buffer into a per-CPU + * queue and thus reduce the number of global (and possibly + * NUMA-alien) accesses. The write-queue is self-coalescing: + */ + local_irq_save(flags); + do { + for (j = 0; j < PROFILE_GRPSZ; ++j) { + if (hits[i + j].pc == pc) { + hits[i + j].hits += nr_hits; + goto out; + } else if (!hits[i + j].hits) { + hits[i + j].pc = pc; + hits[i + j].hits = nr_hits; + goto out; + } + } + i = (i + secondary) & (NR_PROFILE_HIT - 1); + } while (i != primary); + + /* + * Add the current hit(s) and flush the write-queue out + * to the global buffer: + */ + atomic_add(nr_hits, &prof_buffer[pc]); + for (i = 0; i < NR_PROFILE_HIT; ++i) { + atomic_add(hits[i].hits, &prof_buffer[hits[i].pc]); + hits[i].pc = hits[i].hits = 0; + } +out: + local_irq_restore(flags); + put_cpu(); +} + +static int profile_dead_cpu(unsigned int cpu) +{ + struct page *page; + int i; + + if (cpumask_available(prof_cpu_mask)) + cpumask_clear_cpu(cpu, prof_cpu_mask); + + for (i = 0; i < 2; i++) { + if (per_cpu(cpu_profile_hits, cpu)[i]) { + page = virt_to_page(per_cpu(cpu_profile_hits, cpu)[i]); + per_cpu(cpu_profile_hits, cpu)[i] = NULL; + __free_page(page); + } + } + return 0; +} + +static int profile_prepare_cpu(unsigned int cpu) +{ + int i, node = cpu_to_mem(cpu); + struct page *page; + + per_cpu(cpu_profile_flip, cpu) = 0; + + for (i = 0; i < 2; i++) { + if (per_cpu(cpu_profile_hits, cpu)[i]) + continue; + + page = __alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO, 0); + if (!page) { + profile_dead_cpu(cpu); + return -ENOMEM; + } + per_cpu(cpu_profile_hits, cpu)[i] = page_address(page); + + } + return 0; +} + +static int profile_online_cpu(unsigned int cpu) +{ + if (cpumask_available(prof_cpu_mask)) + cpumask_set_cpu(cpu, prof_cpu_mask); + + return 0; +} + +#else /* !CONFIG_SMP */ +#define profile_flip_buffers() do { } while (0) +#define profile_discard_flip_buffers() do { } while (0) + +static void do_profile_hits(int type, void *__pc, unsigned int nr_hits) +{ + unsigned long pc; + pc = ((unsigned long)__pc - (unsigned long)_stext) >> prof_shift; + atomic_add(nr_hits, &prof_buffer[min(pc, prof_len - 1)]); +} +#endif /* !CONFIG_SMP */ + +void profile_hits(int type, void *__pc, unsigned int nr_hits) +{ + if (prof_on != type || !prof_buffer) + return; + do_profile_hits(type, __pc, nr_hits); +} +EXPORT_SYMBOL_GPL(profile_hits); + +void profile_tick(int type) +{ + struct pt_regs *regs = get_irq_regs(); + + if (!user_mode(regs) && cpumask_available(prof_cpu_mask) && + cpumask_test_cpu(smp_processor_id(), prof_cpu_mask)) + profile_hit(type, (void *)profile_pc(regs)); +} + +#ifdef CONFIG_PROC_FS +#include +#include +#include + +static int prof_cpu_mask_proc_show(struct seq_file *m, void *v) +{ + seq_printf(m, "%*pb\n", cpumask_pr_args(prof_cpu_mask)); + return 0; +} + +static int prof_cpu_mask_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, prof_cpu_mask_proc_show, NULL); +} + +static ssize_t prof_cpu_mask_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) +{ + cpumask_var_t new_value; + int err; + + if (!zalloc_cpumask_var(&new_value, GFP_KERNEL)) + return -ENOMEM; + + err = cpumask_parse_user(buffer, count, new_value); + if (!err) { + cpumask_copy(prof_cpu_mask, new_value); + err = count; + } + free_cpumask_var(new_value); + return err; +} + +static const struct proc_ops prof_cpu_mask_proc_ops = { + .proc_open = prof_cpu_mask_proc_open, + .proc_read = seq_read, + .proc_lseek = seq_lseek, + .proc_release = single_release, + .proc_write = prof_cpu_mask_proc_write, +}; + +void create_prof_cpu_mask(void) +{ + /* create /proc/irq/prof_cpu_mask */ + proc_create("irq/prof_cpu_mask", 0600, NULL, &prof_cpu_mask_proc_ops); +} + +/* + * This function accesses profiling information. The returned data is + * binary: the sampling step and the actual contents of the profile + * buffer. Use of the program readprofile is recommended in order to + * get meaningful info out of these data. + */ +static ssize_t +read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) +{ + unsigned long p = *ppos; + ssize_t read; + char *pnt; + unsigned long sample_step = 1UL << prof_shift; + + profile_flip_buffers(); + if (p >= (prof_len+1)*sizeof(unsigned int)) + return 0; + if (count > (prof_len+1)*sizeof(unsigned int) - p) + count = (prof_len+1)*sizeof(unsigned int) - p; + read = 0; + + while (p < sizeof(unsigned int) && count > 0) { + if (put_user(*((char *)(&sample_step)+p), buf)) + return -EFAULT; + buf++; p++; count--; read++; + } + pnt = (char *)prof_buffer + p - sizeof(atomic_t); + if (copy_to_user(buf, (void *)pnt, count)) + return -EFAULT; + read += count; + *ppos += read; + return read; +} + +/* default is to not implement this call */ +int __weak setup_profiling_timer(unsigned mult) +{ + return -EINVAL; +} + +/* + * Writing to /proc/profile resets the counters + * + * Writing a 'profiling multiplier' value into it also re-sets the profiling + * interrupt frequency, on architectures that support this. + */ +static ssize_t write_profile(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ +#ifdef CONFIG_SMP + if (count == sizeof(int)) { + unsigned int multiplier; + + if (copy_from_user(&multiplier, buf, sizeof(int))) + return -EFAULT; + + if (setup_profiling_timer(multiplier)) + return -EINVAL; + } +#endif + profile_discard_flip_buffers(); + memset(prof_buffer, 0, prof_len * sizeof(atomic_t)); + return count; +} + +static const struct proc_ops profile_proc_ops = { + .proc_read = read_profile, + .proc_write = write_profile, + .proc_lseek = default_llseek, +}; + +int __ref create_proc_profile(void) +{ + struct proc_dir_entry *entry; +#ifdef CONFIG_SMP + enum cpuhp_state online_state; +#endif + + int err = 0; + + if (!prof_on) + return 0; +#ifdef CONFIG_SMP + err = cpuhp_setup_state(CPUHP_PROFILE_PREPARE, "PROFILE_PREPARE", + profile_prepare_cpu, profile_dead_cpu); + if (err) + return err; + + err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "AP_PROFILE_ONLINE", + profile_online_cpu, NULL); + if (err < 0) + goto err_state_prep; + online_state = err; + err = 0; +#endif + entry = proc_create("profile", S_IWUSR | S_IRUGO, + NULL, &profile_proc_ops); + if (!entry) + goto err_state_onl; + proc_set_size(entry, (1 + prof_len) * sizeof(atomic_t)); + + return err; +err_state_onl: +#ifdef CONFIG_SMP + cpuhp_remove_state(online_state); +err_state_prep: + cpuhp_remove_state(CPUHP_PROFILE_PREPARE); +#endif + return err; +} +subsys_initcall(create_proc_profile); +#endif /* CONFIG_PROC_FS */ -- cgit v1.2.3