From: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> To: Stephen Boyd <sboyd@kernel.org>, Anton Vorontsov <anton@enomsg.org>, Arnd Bergmann <arnd@arndb.de>, Catalin Marinas <catalin.marinas@arm.com>, Colin Cross <ccross@android.com>, Ingo Molnar <mingo@redhat.com>, Jason Baron <jbaron@akamai.com>, Jim Cromie <jim.cromie@gmail.com>, Joe Perches <joe@perches.com>, Joel Fernandes <joel@joelfernandes.org>, Kees Cook <keescook@chromium.org>, Laura Abbott <labbott@redhat.com>, Masami Hiramatsu <mhiramat@kernel.org>, Rob Herring <robh+dt@kernel.org>, Steven Rostedt <rostedt@goodmis.org>, Tony Luck <tony.luck@intel.com>, Will Deacon <will.deacon@arm.com>, devicetree@vger.kernel.org Cc: Rajendra Nayak <rnayak@codeaurora.org>, Vivek Gautam <vivek.gautam@codeaurora.org>, Sibi Sankar <sibis@codeaurora.org>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Ingo Molnar <mingo@kernel.org>, Tom Zanussi <tom.zanussi@linux.intel.com>, Prasad Sodagudi <psodagud@codeaurora.org>, tsoni@codeaurora.org, Bryan Huntsman <bryanh@codeaurora.org>, Tingwei Zhang <tingwei@codeaurora.org> Subject: Re: [PATCH 2/6] pstore: Add event tracing support Date: Tue, 18 Sep 2018 01:13:30 +0530 [thread overview] Message-ID: <03d47d84-a237-a94e-04ee-4447d8620697@codeaurora.org> (raw) In-Reply-To: <153720590027.119890.15984895820368075914@swboyd.mtv.corp.google.com> On 9/17/2018 11:08 PM, Stephen Boyd wrote: > Quoting Sai Prakash Ranjan (2018-09-11 03:46:01) >> On 9/9/2018 1:57 AM, Sai Prakash Ranjan wrote: >>> +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); >>> + >>> + trace_seq_init(&iter->seq); >>> + iter->ent = fbuffer->entry; >>> + event_call->event.funcs->trace(iter, 0, event); >>> + trace_seq_putc(&iter->seq, 0); >>> + >>> + 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); >>> + >>> + spin_unlock_irqrestore(&psinfo->buf_lock, flags); >>> + >>> +fail_event: >>> + kfree(iter); >>> +} >>> + >>> >> >> When tracing sched events on sdm845 mtp, I hit below bug repeatedly. >> Seems like pstore_event_call can be called in atomic context. >> I will respin the below fix in next version of the patch. >> Reviews on other parts would be appreciated, thanks. >> >> diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c >> index d47dc93ac098..a497cf782ee8 100644 >> --- a/fs/pstore/ftrace.c >> +++ b/fs/pstore/ftrace.c >> @@ -73,6 +73,7 @@ void notrace pstore_event_call(struct >> trace_event_buffer *fbuffer) >> struct trace_event *event; >> struct seq_buf *seq; >> unsigned long flags; >> + gfp_t gfpflags; >> >> if (!psinfo) >> return; >> @@ -83,7 +84,9 @@ void notrace pstore_event_call(struct >> trace_event_buffer *fbuffer) >> pstore_record_init(&record, psinfo); >> record.type = PSTORE_TYPE_EVENT; >> >> - iter = kmalloc(sizeof(*iter), GFP_KERNEL); >> + gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : >> GFP_KERNEL; >> + > Hi Stephen Thanks for the comments. > Do you need to allocate at all? Can you throw the iter on the stack? > Yes since we need to copy the contents to pstore buffer. > Using in_atomic() and irqs_disabled() to figure out if an atomic or a > non-atomic allocation should be used is not a good solution. > I took reference from a similar use by graph_trace_open() which can be called in atomic context via ftrace_dump(). I am open to correct this if there is some other way. Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
WARNING: multiple messages have this Message-ID (diff)
From: saiprakash.ranjan@codeaurora.org (Sai Prakash Ranjan) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/6] pstore: Add event tracing support Date: Tue, 18 Sep 2018 01:13:30 +0530 [thread overview] Message-ID: <03d47d84-a237-a94e-04ee-4447d8620697@codeaurora.org> (raw) In-Reply-To: <153720590027.119890.15984895820368075914@swboyd.mtv.corp.google.com> On 9/17/2018 11:08 PM, Stephen Boyd wrote: > Quoting Sai Prakash Ranjan (2018-09-11 03:46:01) >> On 9/9/2018 1:57 AM, Sai Prakash Ranjan wrote: >>> +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); >>> + >>> + trace_seq_init(&iter->seq); >>> + iter->ent = fbuffer->entry; >>> + event_call->event.funcs->trace(iter, 0, event); >>> + trace_seq_putc(&iter->seq, 0); >>> + >>> + 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); >>> + >>> + spin_unlock_irqrestore(&psinfo->buf_lock, flags); >>> + >>> +fail_event: >>> + kfree(iter); >>> +} >>> + >>> >> >> When tracing sched events on sdm845 mtp, I hit below bug repeatedly. >> Seems like pstore_event_call can be called in atomic context. >> I will respin the below fix in next version of the patch. >> Reviews on other parts would be appreciated, thanks. >> >> diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c >> index d47dc93ac098..a497cf782ee8 100644 >> --- a/fs/pstore/ftrace.c >> +++ b/fs/pstore/ftrace.c >> @@ -73,6 +73,7 @@ void notrace pstore_event_call(struct >> trace_event_buffer *fbuffer) >> struct trace_event *event; >> struct seq_buf *seq; >> unsigned long flags; >> + gfp_t gfpflags; >> >> if (!psinfo) >> return; >> @@ -83,7 +84,9 @@ void notrace pstore_event_call(struct >> trace_event_buffer *fbuffer) >> pstore_record_init(&record, psinfo); >> record.type = PSTORE_TYPE_EVENT; >> >> - iter = kmalloc(sizeof(*iter), GFP_KERNEL); >> + gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : >> GFP_KERNEL; >> + > Hi Stephen Thanks for the comments. > Do you need to allocate at all? Can you throw the iter on the stack? > Yes since we need to copy the contents to pstore buffer. > Using in_atomic() and irqs_disabled() to figure out if an atomic or a > non-atomic allocation should be used is not a good solution. > I took reference from a similar use by graph_trace_open() which can be called in atomic context via ftrace_dump(). I am open to correct this if there is some other way. Sai -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
next prev parent reply other threads:[~2018-09-17 19:43 UTC|newest] Thread overview: 141+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-09-08 20:27 [PATCH 0/6] Tracing register accesses with pstore and dynamic debug Sai Prakash Ranjan 2018-09-08 20:27 ` Sai Prakash Ranjan 2018-09-08 20:27 ` [PATCH 1/6] dt-bindings: ramoops: Add event-size property Sai Prakash Ranjan 2018-09-08 20:27 ` Sai Prakash Ranjan 2018-09-17 5:45 ` Rob Herring 2018-09-17 5:45 ` Rob Herring 2018-09-17 17:15 ` Sai Prakash Ranjan 2018-09-17 17:15 ` Sai Prakash Ranjan 2018-09-08 20:27 ` [PATCH 2/6] pstore: Add event tracing support Sai Prakash Ranjan 2018-09-08 20:27 ` Sai Prakash Ranjan 2018-09-11 10:46 ` Sai Prakash Ranjan 2018-09-11 10:46 ` Sai Prakash Ranjan 2018-09-17 17:38 ` Stephen Boyd 2018-09-17 17:38 ` Stephen Boyd 2018-09-17 19:43 ` Sai Prakash Ranjan [this message] 2018-09-17 19:43 ` Sai Prakash Ranjan 2018-09-16 7:07 ` Sai Prakash Ranjan 2018-09-16 7:07 ` Sai Prakash Ranjan 2018-09-16 13:55 ` Joel Fernandes 2018-09-17 14:54 ` Kees Cook 2018-09-17 14:54 ` Kees Cook 2018-09-17 14:54 ` Kees Cook 2018-09-17 17:17 ` Sai Prakash Ranjan 2018-09-17 17:17 ` Sai Prakash Ranjan 2018-09-17 17:17 ` Sai Prakash Ranjan 2018-09-17 17:13 ` Sai Prakash Ranjan 2018-09-17 17:13 ` Sai Prakash Ranjan 2018-09-17 17:13 ` Sai Prakash Ranjan 2018-09-17 23:04 ` Steven Rostedt 2018-09-17 23:04 ` Steven Rostedt 2018-09-17 23:04 ` Steven Rostedt 2018-09-18 6:24 ` Sai Prakash Ranjan 2018-09-18 6:24 ` Sai Prakash Ranjan 2018-09-18 6:24 ` Sai Prakash Ranjan 2018-09-17 23:34 ` Steven Rostedt 2018-09-17 23:34 ` Steven Rostedt 2018-09-17 23:34 ` Steven Rostedt 2018-09-18 17:52 ` Sai Prakash Ranjan 2018-09-18 17:52 ` Sai Prakash Ranjan 2018-09-18 17:52 ` Sai Prakash Ranjan 2018-09-18 20:44 ` Steven Rostedt 2018-09-18 20:44 ` Steven Rostedt 2018-09-18 20:44 ` Steven Rostedt 2018-09-18 21:13 ` Sai Prakash Ranjan 2018-09-18 21:13 ` Sai Prakash Ranjan 2018-09-18 21:13 ` Sai Prakash Ranjan 2018-09-22 6:48 ` Sai Prakash Ranjan 2018-09-22 6:48 ` Sai Prakash Ranjan 2018-09-22 6:48 ` Sai Prakash Ranjan 2018-09-22 9:05 ` Joel Fernandes 2018-09-22 9:05 ` Joel Fernandes 2018-09-22 9:05 ` Joel Fernandes 2018-09-22 16:37 ` Sai Prakash Ranjan 2018-09-22 16:37 ` Sai Prakash Ranjan 2018-09-22 16:37 ` Sai Prakash Ranjan 2018-09-22 17:32 ` Sai Prakash Ranjan 2018-09-22 17:32 ` Sai Prakash Ranjan 2018-09-22 17:32 ` Sai Prakash Ranjan 2018-09-22 17:45 ` Sai Prakash Ranjan 2018-09-22 17:45 ` Sai Prakash Ranjan 2018-09-22 17:45 ` Sai Prakash Ranjan 2018-09-23 15:33 ` Sai Prakash Ranjan 2018-09-23 15:33 ` Sai Prakash Ranjan 2018-09-23 15:33 ` Sai Prakash Ranjan 2018-09-25 20:37 ` Joel Fernandes 2018-09-25 20:37 ` Joel Fernandes 2018-09-25 20:37 ` Joel Fernandes 2018-09-25 20:39 ` Joel Fernandes 2018-09-25 20:39 ` Joel Fernandes 2018-09-25 20:39 ` Joel Fernandes 2018-09-25 20:40 ` Joel Fernandes 2018-09-25 20:40 ` Joel Fernandes 2018-09-25 20:40 ` Joel Fernandes 2018-09-26 9:52 ` Sai Prakash Ranjan 2018-09-26 9:52 ` Sai Prakash Ranjan 2018-09-26 9:52 ` Sai Prakash Ranjan 2018-09-08 20:27 ` [PATCH 3/6] tracing: Add tp_pstore cmdline to have tracepoints go to pstore Sai Prakash Ranjan 2018-09-08 20:27 ` Sai Prakash Ranjan 2018-09-25 21:25 ` Joel Fernandes 2018-09-25 21:25 ` Joel Fernandes 2018-09-25 21:25 ` Joel Fernandes 2018-09-26 9:46 ` Sai Prakash Ranjan 2018-09-26 9:46 ` Sai Prakash Ranjan 2018-09-26 9:46 ` Sai Prakash Ranjan 2018-10-08 14:16 ` Sai Prakash Ranjan 2018-10-08 14:16 ` Sai Prakash Ranjan 2018-10-08 14:16 ` Sai Prakash Ranjan 2018-10-08 14:36 ` Steven Rostedt 2018-10-08 14:36 ` Steven Rostedt 2018-10-08 14:36 ` Steven Rostedt 2018-10-08 22:40 ` Joel Fernandes 2018-10-08 22:40 ` Joel Fernandes 2018-10-08 22:40 ` Joel Fernandes 2018-10-09 18:22 ` Sai Prakash Ranjan 2018-10-09 18:22 ` Sai Prakash Ranjan 2018-10-09 18:22 ` Sai Prakash Ranjan 2018-10-10 19:37 ` Steven Rostedt 2018-10-10 19:37 ` Steven Rostedt 2018-10-10 19:37 ` Steven Rostedt 2018-09-08 20:27 ` [PATCH 4/6] arm64/io: Add tracepoint for register accesses Sai Prakash Ranjan 2018-09-08 20:27 ` Sai Prakash Ranjan 2018-09-08 20:27 ` [PATCH 5/6] arm64/io: Add header for instrumentation of io operations Sai Prakash Ranjan 2018-09-08 20:27 ` Sai Prakash Ranjan 2018-09-17 23:39 ` Steven Rostedt 2018-09-17 23:39 ` Steven Rostedt 2018-09-17 23:39 ` Steven Rostedt 2018-09-18 7:10 ` Sai Prakash Ranjan 2018-09-18 7:10 ` Sai Prakash Ranjan 2018-09-18 7:10 ` Sai Prakash Ranjan 2018-09-18 11:47 ` Will Deacon 2018-09-18 11:47 ` Will Deacon 2018-09-18 11:47 ` Will Deacon 2018-09-18 12:43 ` Sai Prakash Ranjan 2018-09-18 12:43 ` Sai Prakash Ranjan 2018-09-18 12:43 ` Sai Prakash Ranjan 2018-09-08 20:27 ` [PATCH 6/6] dynamic_debug: Add flag for dynamic event tracing Sai Prakash Ranjan 2018-09-08 20:27 ` Sai Prakash Ranjan 2018-09-11 15:11 ` [PATCH 0/6] Tracing register accesses with pstore and dynamic debug Will Deacon 2018-09-11 15:11 ` Will Deacon 2018-09-11 15:11 ` Will Deacon 2018-09-11 16:11 ` Sai Prakash Ranjan 2018-09-11 16:11 ` Sai Prakash Ranjan 2018-09-11 16:11 ` Sai Prakash Ranjan 2018-10-20 5:25 ` Joel Fernandes 2018-10-20 5:25 ` Joel Fernandes 2018-10-20 5:25 ` Joel Fernandes 2018-10-20 6:32 ` Sai Prakash Ranjan 2018-10-20 6:32 ` Sai Prakash Ranjan 2018-10-20 6:32 ` Sai Prakash Ranjan 2018-10-20 16:27 ` Joel Fernandes 2018-10-20 16:27 ` Joel Fernandes 2018-10-20 16:27 ` Joel Fernandes 2018-10-21 3:46 ` Sai Prakash Ranjan 2018-10-21 3:46 ` Sai Prakash Ranjan 2018-10-21 3:46 ` Sai Prakash Ranjan 2018-10-21 4:59 ` Sai Prakash Ranjan 2018-10-21 4:59 ` Sai Prakash Ranjan 2018-10-21 4:59 ` Sai Prakash Ranjan 2018-10-21 5:09 ` Joel Fernandes 2018-10-21 5:09 ` Joel Fernandes 2018-10-21 5:09 ` Joel Fernandes
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