linux/kernel/trace/blktrace.c, branch v3.9

Revert "block: add missing block_bio_complete() tracepoint"

2013-04-18T16:00:26Z

This reverts commit 3a366e614d0837d9fc23f78cdb1a1186ebc3387f. Wanlong Gao reports that it causes a kernel panic on his machine several minutes after boot. Reverting it removes the panic. Jens says: "It's not quite clear why that is yet, so I think we should just revert the commit for 3.9 final (which I'm assuming is pretty close). The wifi is crap at the LSF hotel, so sending this email instead of queueing up a revert and pull request." Reported-by: Wanlong Gao Requested-by: Jens Axboe Cc: Tejun Heo Cc: Steven Rostedt Signed-off-by: Linus Torvalds

Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block

2013-02-28T20:52:24Z

Pull block IO core bits from Jens Axboe: "Below are the core block IO bits for 3.9. It was delayed a few days since my workstation kept crashing every 2-8h after pulling it into current -git, but turns out it is a bug in the new pstate code (divide by zero, will report separately). In any case, it contains: - The big cfq/blkcg update from Tejun and and Vivek. - Additional block and writeback tracepoints from Tejun. - Improvement of the should sort (based on queues) logic in the plug flushing. - _io() variants of the wait_for_completion() interface, using io_schedule() instead of schedule() to contribute to io wait properly. - Various little fixes. You'll get two trivial merge conflicts, which should be easy enough to fix up" Fix up the trivial conflicts due to hlist traversal cleanups (commit b67bfe0d42ca: "hlist: drop the node parameter from iterators"). * 'for-3.9/core' of git://git.kernel.dk/linux-block: (39 commits) block: remove redundant check to bd_openers() block: use i_size_write() in bd_set_size() cfq: fix lock imbalance with failed allocations drivers/block/swim3.c: fix null pointer dereference block: don't select PERCPU_RWSEM block: account iowait time when waiting for completion of IO request sched: add wait_for_completion_io[_timeout] writeback: add more tracepoints block: add block_{touch|dirty}_buffer tracepoint buffer: make touch_buffer() an exported function block: add @req to bio_{front|back}_merge tracepoints block: add missing block_bio_complete() tracepoint block: Remove should_sort judgement when flush blk_plug block,elevator: use new hashtable implementation cfq-iosched: add hierarchical cfq_group statistics cfq-iosched: collect stats from dead cfqgs cfq-iosched: separate out cfqg_stats_reset() from cfq_pd_reset_stats() blkcg: make blkcg_print_blkgs() grab q locks instead of blkcg lock block: RCU free request_queue blkcg: implement blkg_[rw]stat_recursive_sum() and blkg_[rw]stat_merge() ...

tracing: Use this_cpu_ptr per-cpu helper

2013-01-21T18:22:30Z

typeof(&buffer) is a pointer to array of 1024 char, or char (*)[1024]. But, typeof(&buffer[0]) is a pointer to char which match the return type of get_trace_buf(). As well-known, the value of &buffer is equal to &buffer[0]. so return this_cpu_ptr(&percpu_buffer->buffer[0]) can avoid type cast. Link: http://lkml.kernel.org/r/50A1A800.3020102@gmail.com Reviewed-by: Christoph Lameter Signed-off-by: Shan Wei Signed-off-by: Steven Rostedt

block: add @req to bio_{front|back}_merge tracepoints

2013-01-14T14:00:36Z

bio_{front|back}_merge tracepoints report a bio merging into an existing request but didn't specify which request the bio is being merged into. Add @req to it. This makes it impossible to share the event template with block_bio_queue - split it out. @req isn't used or exported to userland at this point and there is no userland visible behavior change. Later changes will make use of the extra parameter. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe

block: add missing block_bio_complete() tracepoint

2013-01-14T14:00:36Z

bio completion didn't kick block_bio_complete TP. Only dm was explicitly triggering the TP on IO completion. This makes block_bio_complete TP useless for tracers which want to know about bios, and all other bio based drivers skip generating blktrace completion events. This patch makes all bio completions via bio_endio() generate block_bio_complete TP. * Explicit trace_block_bio_complete() invocation removed from dm and the trace point is unexported. * @rq dropped from trace_block_bio_complete(). bios may fly around w/o queue associated. Verifying and accessing the assocaited queue belongs to TP probes. * blktrace now gets both request and bio completions. Make it ignore bio completions if request completion path is happening. This makes all bio based drivers generate blktrace completion events properly and makes the block_bio_complete TP actually useful. v2: With this change, block_bio_complete TP could be invoked on sg commands which have bio's with %NULL bi_bdev. Update TP assignment code to check whether bio->bi_bdev is %NULL before dereferencing. Signed-off-by: Tejun Heo Original-patch-by: Namhyung Kim Cc: Tejun Heo Cc: Steven Rostedt Cc: Alasdair Kergon Cc: dm-devel@redhat.com Cc: Neil Brown Signed-off-by: Jens Axboe

simple_open: automatically convert to simple_open()

2012-04-05T22:25:50Z

Many users of debugfs copy the implementation of default_open() when they want to support a custom read/write function op. This leads to a proliferation of the default_open() implementation across the entire tree. Now that the common implementation has been consolidated into libfs we can replace all the users of this function with simple_open(). This replacement was done with the following semantic patch: @ open @ identifier open_f != simple_open; identifier i, f; @@ -int open_f(struct inode *i, struct file *f) -{ ( -if (i->i_private) -f->private_data = i->i_private; | -f->private_data = i->i_private; ) -return 0; -} @ has_open depends on open @ identifier fops; identifier open.open_f; @@ struct file_operations fops = { ... -.open = open_f, +.open = simple_open, ... }; [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Stephen Boyd Cc: Greg Kroah-Hartman Cc: Al Viro Cc: Julia Lawall Acked-by: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

switch debugfs to umode_t

2012-01-04T03:54:56Z

Signed-off-by: Al Viro

kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure

2011-10-31T23:30:05Z

These files were getting via an implicit non-obvious path, but we want to crush those out of existence since they cost time during compiles of processing thousands of lines of headers for no reason. Give them the lightweight header that just contains the EXPORT_SYMBOL infrastructure. Signed-off-by: Paul Gortmaker

blktrace: add FLUSH/FUA support

2011-08-11T08:36:05Z

Add FLUSH/FUA support to blktrace. As FLUSH precedes WRITE and/or FUA follows WRITE, use the same 'F' flag for both cases and distinguish them by their (relative) position. The end results look like (other flags might be shown also): - WRITE: W - WRITE_FLUSH: FW - WRITE_FUA: WF - WRITE_FLUSH_FUA: FWF Note that we reuse TC_BARRIER due to lack of bit space of act_mask so that the older versions of blktrace tools will report flush requests as barriers from now on. Cc: Steven Rostedt Cc: Frederic Weisbecker Cc: Ingo Molnar Signed-off-by: Namhyung Kim Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe

block: make unplug timer trace event correspond to the schedule() unplug

2011-04-16T11:51:05Z

It's a pretty close match to what we had before - the timer triggering would mean that nobody unplugged the plug in due time, in the new scheme this matches very closely what the schedule() unplug now is. It's essentially the difference between an explicit unplug (IO unplug) or an implicit unplug (timer unplug, we scheduled with pending IO queued). Signed-off-by: Jens Axboe