kernel/linux.git/include/trace/events/sunrpc.h, branch v4.14.85

SUNRPC: Fix tracepoint storage issues with svc_recv and svc_rqst_status

2017-11-30T08:40:53+00:00

commit e9d4bf219c83d09579bc62512fea2ca10f025d93 upstream. There is no guarantee that either the request or the svc_xprt exist by the time we get round to printing the trace message. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

SUNRPC: Add tracepoints for dropped and deferred requests

2016-07-13T19:53:43+00:00

Dropping and/or deferring requests has an impact on performance. Let's make sure we can trace those events. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields

SUNRPC: Add a tracepoint for server socket out-of-space conditions

2016-07-13T19:53:42+00:00

Add a tracepoint to track when the processing of incoming RPC data gets deferred due to out-of-space issues on the outgoing transport. Signed-off-by: Trond Myklebust Signed-off-by: J. Bruce Fields

SUNRPC: Don't allocate a full sockaddr_storage for tracing

2016-07-01T20:28:44+00:00

We're always tracing IPv4 or IPv6 addresses, so we can save a lot of space on the ringbuffer by allocating the correct sockaddr size. Signed-off-by: Trond Myklebust Cc: stable@vger.kernel.org Fixes: 83a712e0afef "sunrpc: add some tracepoints around ..." Signed-off-by: J. Bruce Fields

net: sunrpc: fix tracepoint Warning: unknown op '->'

2015-08-31T20:32:15+00:00

`perf stat -e sunrpc:svc_xprt_do_enqueue true` results in Warning: unknown op '->' Warning: [sunrpc:svc_xprt_do_enqueue] unknown op '->' Similar warning for svc_handle_xprt as well. Actually TP_printk() should never dereference an address saved in the ring buffer that points somewhere in the kernel. There's no guarantee that that object still exists (with the exception of static strings). Therefore change all the arguments for TP_printk(), so that it references values existing in the ring buffer only. While doing that, also fix another possible bug when argument xprt could be NULL and TP_fast_assign() tries to access it's elements. Signed-off-by: Pratyush Anand Reviewed-by: Jeff Layton Acked-by: Steven Rostedt Cc: stable@vger.kernel.org Fixes: 83a712e0afef "sunrpc: add some tracepoints around ..." Signed-off-by: J. Bruce Fields

SUNRPC: Export enums in tracepoints to user space

2015-04-08T13:41:08+00:00

The enums used in the tracepoints for __print_symbolic() have their names shown in the tracepoint format files. User space tools do not know how to convert those names into their values to be able to convert the binary data. Use TRACE_DEFINE_ENUM() to export the enum names to their values for userspace to do the parsing correctly. Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org Acked-by: Trond Myklebust Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu Signed-off-by: Steven Rostedt

sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt

2014-12-09T16:29:14+00:00

These were useful when I was tracking down a race condition between svc_xprt_do_enqueue and svc_get_next_xprt. Signed-off-by: Jeff Layton Signed-off-by: J. Bruce Fields

sunrpc: convert to lockless lookup of queued server threads

2014-12-09T16:22:22+00:00

Testing has shown that the pool->sp_lock can be a bottleneck on a busy server. Every time data is received on a socket, the server must take that lock in order to dequeue a thread from the sp_threads list. Address this problem by eliminating the sp_threads list (which contains threads that are currently idle) and replacing it with a RQ_BUSY flag in svc_rqst. This allows us to walk the sp_all_threads list under the rcu_read_lock and find a suitable thread for the xprt by doing a test_and_set_bit. Note that we do still have a potential atomicity problem however with this approach. We don't want svc_xprt_do_enqueue to set the rqst->rq_xprt pointer unless a test_and_set_bit of RQ_BUSY returned zero (which indicates that the thread was idle). But, by the time we check that, the bit could be flipped by a waking thread. To address this, we acquire a new per-rqst spinlock (rq_lock) and take that before doing the test_and_set_bit. If that returns false, then we can set rq_xprt and drop the spinlock. Then, when the thread wakes up, it must set the bit under the same spinlock and can trust that if it was already set then the rq_xprt is also properly set. With this scheme, the case where we have an idle thread no longer needs to take the highly contended pool->sp_lock at all, and that removes the bottleneck. That still leaves one issue: What of the case where we walk the whole sp_all_threads list and don't find an idle thread? Because the search is lockess, it's possible for the queueing to race with a thread that is going to sleep. To address that, we queue the xprt and then search again. If we find an idle thread at that point, we can't attach the xprt to it directly since that might race with a different thread waking up and finding it. All we can do is wake the idle thread back up and let it attempt to find the now-queued xprt. Signed-off-by: Jeff Layton Tested-by: Chris Worley Signed-off-by: J. Bruce Fields

sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it

2014-12-09T16:22:22+00:00

...also make the manipulation of sp_all_threads list use RCU-friendly functions. Signed-off-by: Jeff Layton Tested-by: Chris Worley Signed-off-by: J. Bruce Fields