[PATCH 2/6] pstore: Add event tracing support
From: Joel Fernandes <hidden>
Date: 2018-09-22 09:05:43
Also in:
linux-arm-msm, linux-devicetree, lkml
On Sat, Sep 8, 2018 at 4:28 PM Sai Prakash Ranjan [off-list ref] wrote:
Currently pstore has function trace support which can be used to get the function call chain with limited data. Event tracing has extra data which is useful to debug wide variety of issues and is heavily used across the kernel.
[...]
quoted hunk ↗ jump to hunk
Signed-off-by: Sai Prakash Ranjan <redacted> --- fs/pstore/Kconfig | 2 +- fs/pstore/ftrace.c | 55 ++++++++++++++++++++++++++++++++++++++ fs/pstore/inode.c | 4 +++ fs/pstore/ram.c | 44 +++++++++++++++++++++++++++--- include/linux/pstore.h | 2 ++ include/linux/pstore_ram.h | 1 + 6 files changed, 104 insertions(+), 4 deletions(-)diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index 503086f7f7c1..6fe087b13a51 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig@@ -126,7 +126,7 @@ config PSTORE_PMSG config PSTORE_FTRACE bool "Persistent function tracer" - depends on PSTORE + depends on PSTORE && PSTORE!=m depends on FUNCTION_TRACER depends on DEBUG_FS helpdiff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index 06aab07b6bb7..d47dc93ac098 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c@@ -24,6 +24,8 @@ #include <linux/debugfs.h> #include <linux/err.h> #include <linux/cache.h> +#include <linux/slab.h> +#include <linux/trace_events.h> #include <asm/barrier.h> #include "internal.h"@@ -62,6 +64,59 @@ static struct ftrace_ops pstore_ftrace_ops __read_mostly = { .func = pstore_ftrace_call, }; +void notrace pstore_event_call(struct trace_event_buffer *fbuffer) +{ + struct trace_iterator *iter; + struct trace_seq *s; + struct trace_event_call *event_call; + struct pstore_record record; + struct trace_event *event; + struct seq_buf *seq; + unsigned long flags; + + if (!psinfo) + return; + + if (unlikely(oops_in_progress)) + return; + + pstore_record_init(&record, psinfo); + record.type = PSTORE_TYPE_EVENT; + + iter = kmalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) + return; + + event_call = fbuffer->trace_file->event_call; + if (!event_call || !event_call->event.funcs || + !event_call->event.funcs->trace) + goto fail_event; + + event = &fbuffer->trace_file->event_call->event; + + spin_lock_irqsave(&psinfo->buf_lock, flags);
Could you just split the pstore space into a per-cpu event buffer like we are doing for ftrace-on-pstore? Then you don't need to lock. I fear the lock contention will be apparent. The pstore code already has plumbing to split the store buffer per CPU. Also I think this spinlock can be moved further down.
+ + trace_seq_init(&iter->seq); + iter->ent = fbuffer->entry; + event_call->event.funcs->trace(iter, 0, event); + trace_seq_putc(&iter->seq, 0);
Would it be possible to store the binary trace record in the pstore buffer instead of outputting text? I suspect that will both be faster and less space.
+ + if (seq->size > psinfo->bufsize) + seq->size = psinfo->bufsize; + + s = &iter->seq; + seq = &s->seq; + + record.buf = (char *)(seq->buffer); + record.size = seq->len; + psinfo->write(&record);
thanks, - Joel
quoted hunk ↗ jump to hunk
+ + spin_unlock_irqrestore(&psinfo->buf_lock, flags); + +fail_event: + kfree(iter); +} + static DEFINE_MUTEX(pstore_ftrace_lock); static bool pstore_ftrace_enabled;diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 5fcb845b9fec..f099152abbbd 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c@@ -345,6 +345,10 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record) scnprintf(name, sizeof(name), "console-%s-%llu", record->psi->name, record->id); break; + case PSTORE_TYPE_EVENT: + scnprintf(name, sizeof(name), "event-%s-%llu", + record->psi->name, record->id); + break; case PSTORE_TYPE_FTRACE: scnprintf(name, sizeof(name), "ftrace-%s-%llu", record->psi->name, record->id);diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index bbd1e357c23d..f60d41c0309e 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c@@ -48,6 +48,10 @@ static ulong ramoops_console_size = MIN_MEM_SIZE; module_param_named(console_size, ramoops_console_size, ulong, 0400); MODULE_PARM_DESC(console_size, "size of kernel console log"); +static ulong ramoops_event_size = MIN_MEM_SIZE; +module_param_named(event_size, ramoops_event_size, ulong, 0400); +MODULE_PARM_DESC(event_size, "size of event log"); + static ulong ramoops_ftrace_size = MIN_MEM_SIZE; module_param_named(ftrace_size, ramoops_ftrace_size, ulong, 0400); MODULE_PARM_DESC(ftrace_size, "size of ftrace log");@@ -86,6 +90,7 @@ MODULE_PARM_DESC(ramoops_ecc, struct ramoops_context { struct persistent_ram_zone **dprzs; /* Oops dump zones */ struct persistent_ram_zone *cprz; /* Console zone */ + struct persistent_ram_zone *eprz; /* Event zone */ struct persistent_ram_zone **fprzs; /* Ftrace zones */ struct persistent_ram_zone *mprz; /* PMSG zone */ phys_addr_t phys_addr;@@ -93,6 +98,7 @@ struct ramoops_context { unsigned int memtype; size_t record_size; size_t console_size; + size_t event_size; size_t ftrace_size; size_t pmsg_size; int dump_oops;@@ -103,6 +109,7 @@ struct ramoops_context { /* _read_cnt need clear on ramoops_pstore_open */ unsigned int dump_read_cnt; unsigned int console_read_cnt; + unsigned int event_read_cnt; unsigned int max_ftrace_cnt; unsigned int ftrace_read_cnt; unsigned int pmsg_read_cnt;@@ -118,6 +125,7 @@ static int ramoops_pstore_open(struct pstore_info *psi) cxt->dump_read_cnt = 0; cxt->console_read_cnt = 0; + cxt->event_read_cnt = 0; cxt->ftrace_read_cnt = 0; cxt->pmsg_read_cnt = 0; return 0;@@ -277,6 +285,11 @@ static ssize_t ramoops_pstore_read(struct pstore_record *record) 1, &record->id, &record->type, PSTORE_TYPE_CONSOLE, 0); + if (!prz_ok(prz)) + prz = ramoops_get_next_prz(&cxt->eprz, &cxt->event_read_cnt, + 1, &record->id, &record->type, + PSTORE_TYPE_EVENT, 0); + if (!prz_ok(prz)) prz = ramoops_get_next_prz(&cxt->mprz, &cxt->pmsg_read_cnt, 1, &record->id, &record->type,@@ -385,6 +398,11 @@ static int notrace ramoops_pstore_write(struct pstore_record *record) return -ENOMEM; persistent_ram_write(cxt->cprz, record->buf, record->size); return 0; + } else if (record->type == PSTORE_TYPE_EVENT) { + if (!cxt->eprz) + return -ENOMEM; + persistent_ram_write(cxt->eprz, record->buf, record->size); + return 0; } else if (record->type == PSTORE_TYPE_FTRACE) { int zonenum;@@ -475,6 +493,9 @@ static int ramoops_pstore_erase(struct pstore_record *record) case PSTORE_TYPE_CONSOLE: prz = cxt->cprz; break; + case PSTORE_TYPE_EVENT: + prz = cxt->eprz; + break; case PSTORE_TYPE_FTRACE: if (record->id >= cxt->max_ftrace_cnt) return -EINVAL;@@ -699,6 +720,7 @@ static int ramoops_parse_dt(struct platform_device *pdev, parse_size("record-size", pdata->record_size); parse_size("console-size", pdata->console_size); + parse_size("event-size", pdata->event_size); parse_size("ftrace-size", pdata->ftrace_size); parse_size("pmsg-size", pdata->pmsg_size); parse_size("ecc-size", pdata->ecc_info.ecc_size);@@ -747,7 +769,8 @@ static int ramoops_probe(struct platform_device *pdev) } if (!pdata->mem_size || (!pdata->record_size && !pdata->console_size && - !pdata->ftrace_size && !pdata->pmsg_size)) { + !pdata->event_size && !pdata->ftrace_size && + !pdata->pmsg_size)) { pr_err("The memory size and the record/console size must be " "non-zero\n"); goto fail_out;@@ -757,6 +780,8 @@ static int ramoops_probe(struct platform_device *pdev) pdata->record_size = rounddown_pow_of_two(pdata->record_size); if (pdata->console_size && !is_power_of_2(pdata->console_size)) pdata->console_size = rounddown_pow_of_two(pdata->console_size); + if (pdata->event_size && !is_power_of_2(pdata->event_size)) + pdata->event_size = rounddown_pow_of_two(pdata->event_size); if (pdata->ftrace_size && !is_power_of_2(pdata->ftrace_size)) pdata->ftrace_size = rounddown_pow_of_two(pdata->ftrace_size); if (pdata->pmsg_size && !is_power_of_2(pdata->pmsg_size))@@ -767,6 +792,7 @@ static int ramoops_probe(struct platform_device *pdev) cxt->memtype = pdata->mem_type; cxt->record_size = pdata->record_size; cxt->console_size = pdata->console_size; + cxt->event_size = pdata->event_size; cxt->ftrace_size = pdata->ftrace_size; cxt->pmsg_size = pdata->pmsg_size; cxt->dump_oops = pdata->dump_oops;@@ -775,8 +801,8 @@ static int ramoops_probe(struct platform_device *pdev) paddr = cxt->phys_addr; - dump_mem_sz = cxt->size - cxt->console_size - cxt->ftrace_size - - cxt->pmsg_size; + dump_mem_sz = cxt->size - cxt->console_size - cxt->event_size + - cxt->ftrace_size - cxt->pmsg_size; err = ramoops_init_przs("dump", dev, cxt, &cxt->dprzs, &paddr, dump_mem_sz, cxt->record_size, &cxt->max_dump_cnt, 0, 0);@@ -788,6 +814,11 @@ static int ramoops_probe(struct platform_device *pdev) if (err) goto fail_init_cprz; + err = ramoops_init_prz("event", dev, cxt, &cxt->eprz, &paddr, + cxt->event_size, 0); + if (err) + goto fail_init_eprz; + cxt->max_ftrace_cnt = (cxt->flags & RAMOOPS_FLAG_FTRACE_PER_CPU) ? nr_cpu_ids : 1;@@ -825,6 +856,8 @@ static int ramoops_probe(struct platform_device *pdev) cxt->pstore.flags = PSTORE_FLAGS_DMESG; if (cxt->console_size) cxt->pstore.flags |= PSTORE_FLAGS_CONSOLE; + if (cxt->event_size) + cxt->pstore.flags |= PSTORE_FLAGS_EVENT; if (cxt->ftrace_size) cxt->pstore.flags |= PSTORE_FLAGS_FTRACE; if (cxt->pmsg_size)@@ -845,6 +878,7 @@ static int ramoops_probe(struct platform_device *pdev) record_size = pdata->record_size; dump_oops = pdata->dump_oops; ramoops_console_size = pdata->console_size; + ramoops_event_size = pdata->event_size; ramoops_pmsg_size = pdata->pmsg_size; ramoops_ftrace_size = pdata->ftrace_size;@@ -858,6 +892,8 @@ static int ramoops_probe(struct platform_device *pdev) kfree(cxt->pstore.buf); fail_clear: cxt->pstore.bufsize = 0; + persistent_ram_free(cxt->eprz); +fail_init_eprz: persistent_ram_free(cxt->mprz); fail_init_mprz: fail_init_fprz:@@ -877,6 +913,7 @@ static int ramoops_remove(struct platform_device *pdev) kfree(cxt->pstore.buf); cxt->pstore.bufsize = 0; + persistent_ram_free(cxt->eprz); persistent_ram_free(cxt->mprz); persistent_ram_free(cxt->cprz); ramoops_free_przs(cxt);@@ -916,6 +953,7 @@ static void ramoops_register_dummy(void) dummy_data->mem_type = mem_type; dummy_data->record_size = record_size; dummy_data->console_size = ramoops_console_size; + dummy_data->event_size = ramoops_event_size; dummy_data->ftrace_size = ramoops_ftrace_size; dummy_data->pmsg_size = ramoops_pmsg_size; dummy_data->dump_oops = dump_oops;diff --git a/include/linux/pstore.h b/include/linux/pstore.h index a15bc4d48752..c31bb9567b4a 100644 --- a/include/linux/pstore.h +++ b/include/linux/pstore.h@@ -44,6 +44,7 @@ enum pstore_type_id { PSTORE_TYPE_PPC_COMMON = 6, PSTORE_TYPE_PMSG = 7, PSTORE_TYPE_PPC_OPAL = 8, + PSTORE_TYPE_EVENT = 9, PSTORE_TYPE_UNKNOWN = 255 };@@ -193,6 +194,7 @@ struct pstore_info { #define PSTORE_FLAGS_CONSOLE (1 << 1) #define PSTORE_FLAGS_FTRACE (1 << 2) #define PSTORE_FLAGS_PMSG (1 << 3) +#define PSTORE_FLAGS_EVENT (1 << 4) extern int pstore_register(struct pstore_info *); extern void pstore_unregister(struct pstore_info *);diff --git a/include/linux/pstore_ram.h b/include/linux/pstore_ram.h index e6d226464838..f01055c6cc40 100644 --- a/include/linux/pstore_ram.h +++ b/include/linux/pstore_ram.h@@ -95,6 +95,7 @@ struct ramoops_platform_data { unsigned int mem_type; unsigned long record_size; unsigned long console_size; + unsigned long event_size; unsigned long ftrace_size; unsigned long pmsg_size; int dump_oops; --QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation