On Fri, 27 Jun 2014 15:48:10 +0200 Petr Mládek <pmla...@suse.cz> wrote:
> On Thu 2014-06-26 17:49:04, Steven Rostedt wrote: > > From: "Steven Rostedt (Red Hat)" <rost...@goodmis.org> > > > > The seq_buf functions are rather useful outside of tracing. Instead > > of having it be dependent on CONFIG_TRACING, move the code into lib/ > > and allow other users to have access to it even when tracing is not > > configured. > > > > The seq_buf utility is similar to the seq_file utility, but instead of > > writing sending data back up to userland, it writes it into a buffer > > defined at seq_buf_init(). This allows us to send a descriptor around > > that writes printf() formatted strings into it that can be retrieved > > later. > > > > It is currently used by the tracing facility for such things like trace > > events to convert its binary saved data in the ring buffer into an > > ASCII human readable context to be displayed in /sys/kernel/debug/trace. > > > > It can also be used for doing NMI prints safely from NMI context into > > the seq_buf and retrieved later and dumped to printk() safely. Doing > > printk() from an NMI context is dangerous because an NMI can preempt > > a current printk() and deadlock on it. > > > > Link: http://lkml.kernel.org/p/20140619213952.058255...@goodmis.org > > > > Signed-off-by: Steven Rostedt <rost...@goodmis.org> > > --- > > kernel/trace/seq_buf.c | 348 > > ------------------------------------------------- > > lib/Makefile | 2 +- > > lib/seq_buf.c | 348 > > +++++++++++++++++++++++++++++++++++++++++++++++++ > > lib/trace_seq.c | 303 ++++++++++++++++++++++++++++++++++++++++++ > > I guess that lib/trace_seq.c was copied by mistake. Heh, that's what I get for using both quilt and git :-) To start with what I had before (and use my scripts for the Link tag), I pulled the old patch from my email and pulled it into a quilt queue. Did a "quilt push -f" and then started from there. I removed all the trace_seq.c updates but forgot that quilt push -f would create the file in lib/. When done with all my updates, I just did a git am of the patch in my quilt queue, which pulled in the old copy of trace_seq.c in lib/ :-p I'll remove it. > > > 4 files changed, 652 insertions(+), 349 deletions(-) > > delete mode 100644 kernel/trace/seq_buf.c > > create mode 100644 lib/seq_buf.c > > create mode 100644 lib/trace_seq.c > > > > diff --git a/lib/Makefile b/lib/Makefile > > index ba967a19edba..6007194082c6 100644 > > --- a/lib/Makefile > > +++ b/lib/Makefile > > @@ -13,7 +13,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ > > sha1.o md5.o irq_regs.o reciprocal_div.o argv_split.o \ > > proportions.o flex_proportions.o prio_heap.o ratelimit.o show_mem.o \ > > is_single_threaded.o plist.o decompress.o kobject_uevent.o \ > > - earlycpio.o > > + earlycpio.o seq_buf.o > > > > obj-$(CONFIG_ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS) += usercopy.o > > lib-$(CONFIG_MMU) += ioremap.o > > There is missing: Nope, it just was copied by mistake. It only added dead code, it didn't move it. -- Steve > > diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile > index edc98c72a634..67d6369ddf83 100644 > --- a/kernel/trace/Makefile > +++ b/kernel/trace/Makefile > @@ -29,7 +29,6 @@ obj-$(CONFIG_RING_BUFFER_BENCHMARK) += > ring_buffer_benchmark.o > obj-$(CONFIG_TRACING) += trace.o > obj-$(CONFIG_TRACING) += trace_output.o > obj-$(CONFIG_TRACING) += trace_seq.o > -obj-$(CONFIG_TRACING) += seq_buf.o > obj-$(CONFIG_TRACING) += trace_stat.o > obj-$(CONFIG_TRACING) += trace_printk.o > obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o > > > Best Regards, > Petr -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
