From: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
To: linux-btrace@vger.kernel.org
Subject: [RFC PATCH 06/39] blktrace: add trace note APIs
Date: Mon, 23 Mar 2020 16:29:49 +0000 [thread overview]
Message-ID: <20200323163022.30688-7-chaitanya.kulkarni@wdc.com> (raw)
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
kernel/trace/blktrace.c | 113 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 113 insertions(+)
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index cf69f2f50e6f..2b2e37303926 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -111,6 +111,52 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action,
}
}
+static void trace_note_ext(struct blk_trace_ext *bt, pid_t pid, u64 action,
+ const void *data, size_t len, u64 cgid, u32 ioprio)
+{
+ struct blk_io_trace_ext *t;
+ struct ring_buffer_event *event = NULL;
+ struct trace_buffer *buffer = NULL;
+ int pc = 0;
+ int cpu = smp_processor_id();
+ bool blk_tracer = blk_tracer_enabled;
+ ssize_t cgid_len = cgid ? sizeof(cgid) : 0;
+
+ if (blk_tracer) {
+ buffer = blk_tr->array_buffer.buffer;
+ pc = preempt_count();
+ event = trace_buffer_lock_reserve(buffer, TRACE_BLK,
+ sizeof(*t) + len + cgid_len,
+ 0, pc);
+ if (!event)
+ return;
+ t = ring_buffer_event_data(event);
+ goto record_it;
+ }
+
+ if (!bt->rchan)
+ return;
+
+ t = relay_reserve(bt->rchan, sizeof(*t) + len + cgid_len);
+ if (t) {
+ t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION_EXT;
+ t->time = ktime_to_ns(ktime_get());
+record_it:
+ t->device = bt->dev;
+ t->action = action | (cgid ? __BLK_TN_CGROUP : 0);
+ t->ioprio = ioprio;
+ t->pid = pid;
+ t->cpu = cpu;
+ t->pdu_len = len + cgid_len;
+ if (cgid_len)
+ memcpy((void *)t + sizeof(*t), &cgid, cgid_len);
+ memcpy((void *) t + sizeof(*t) + cgid_len, data, len);
+
+ if (blk_tracer)
+ trace_buffer_unlock_commit(blk_tr, buffer, event, 0, pc);
+ }
+}
+
/*
* Send out a notify for this process, if we haven't done so since a trace
* started
@@ -129,6 +175,20 @@ static void trace_note_tsk(struct task_struct *tsk)
spin_unlock_irqrestore(&running_trace_lock, flags);
}
+static void trace_note_tsk_ext(struct task_struct *tsk, u32 ioprio)
+{
+ unsigned long flags;
+ struct blk_trace_ext *bt;
+
+ tsk->btrace_seq = blktrace_seq;
+ spin_lock_irqsave(&running_trace_ext_lock, flags);
+ list_for_each_entry(bt, &running_trace_ext_list, running_ext_list) {
+ trace_note_ext(bt, tsk->pid, BLK_TN_PROCESS_EXT, tsk->comm,
+ sizeof(tsk->comm), 0, ioprio);
+ }
+ spin_unlock_irqrestore(&running_trace_ext_lock, flags);
+}
+
static void trace_note_time(struct blk_trace *bt)
{
struct timespec64 now;
@@ -145,6 +205,22 @@ static void trace_note_time(struct blk_trace *bt)
local_irq_restore(flags);
}
+static void trace_note_time_ext(struct blk_trace_ext *bt)
+{
+ struct timespec64 now;
+ unsigned long flags;
+ u32 words[2];
+
+ /* need to check user space to see if this breaks in y2038 or y2106 */
+ ktime_get_real_ts64(&now);
+ words[0] = (u32)now.tv_sec;
+ words[1] = now.tv_nsec;
+
+ local_irq_save(flags);
+ trace_note_ext(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words), 0, 0);
+ local_irq_restore(flags);
+}
+
void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
const char *fmt, ...)
{
@@ -182,6 +258,43 @@ void __trace_note_message(struct blk_trace *bt, struct blkcg *blkcg,
}
EXPORT_SYMBOL_GPL(__trace_note_message);
+void __trace_note_message_ext(struct blk_trace_ext *bt, struct blkcg *blkcg,
+ const char *fmt, ...)
+{
+ int n;
+ va_list args;
+ unsigned long flags;
+ char *buf;
+
+ if (unlikely(bt->trace_state != Blktrace_running &&
+ !blk_tracer_enabled))
+ return;
+
+ /*
+ * If the BLK_TC_NOTIFY action mask isn't set, don't send any note
+ * message to the trace.
+ */
+ if (!(bt->act_mask & BLK_TC_NOTIFY))
+ return;
+
+ local_irq_save(flags);
+ buf = this_cpu_ptr(bt->msg_data);
+ va_start(args, fmt);
+ n = vscnprintf(buf, BLK_TN_MAX_MSG, fmt, args);
+ va_end(args);
+
+ if (!(blk_tracer_flags.val & TRACE_BLK_OPT_CGROUP))
+ blkcg = NULL;
+#ifdef CONFIG_BLK_CGROUP
+ trace_note_ext(bt, 0, BLK_TN_MESSAGE_EXT, buf, n,
+ blkcg ? cgroup_id(blkcg->css.cgroup) : 1, 0);
+#else
+ trace_note_ext(bt, 0, BLK_TN_MESSAGE_EXT, buf, n, 0, 0);
+#endif
+ local_irq_restore(flags);
+}
+EXPORT_SYMBOL_GPL(__trace_note_message_ext);
+
static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
pid_t pid)
{
--
2.22.0
next reply other threads:[~2020-03-23 16:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-23 16:29 Chaitanya Kulkarni [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-11-20 4:24 [RFC PATCH 06/39] blktrace: add trace note APIs Chaitanya Kulkarni
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