Building tools/perf fails on next

Hi,

The commit:

commit d72da4a4d973d8a0a0d3c97e7cdebf287fbe3a99

Author: Peter Zijlstra <[email protected]>
Date:   Wed May 27 11:09:36 2015 +0930

rbtree: Make lockless searches non-fatal

Adds <linux/rcupdate.h> to rbtree.h, which in turn is included from perf userspace headers. Now building tools/perf will fail with hundreds of lines of gcc complaining about kernel defines not available. Reverting the patch makes perf build again. This is with gcc-4.9 from debian but I don't think it's compiler specific.

Beginning of build error:

$ make -C tools/perf
make: Entering directory '/build/linux/tools/perf'
  BUILD:   Doing 'make -j4' parallel build

Auto-detecting system features:

...                         dwarf: [ on  ]
...                         glibc: [ on  ]
...                          gtk2: [ OFF ]
...                      libaudit: [ on  ]
...                        libbfd: [ OFF ]
...                        libelf: [ on  ]
...                       libnuma: [ on  ]
...                       libperl: [ on  ]
...                     libpython: [ on  ]
...                      libslang: [ on  ]
...                     libunwind: [ on  ]
...            libdw-dwarf-unwind: [ on  ]
...                          zlib: [ on  ]

... lzma: [ OFF ]

config/Makefile:395: GTK2 not found, disables GTK2 support. Please install gtk2-devel or libgtk2.0-dev config/Makefile:527: No bfd.h/libbfd found, please install binutils-dev[el]/zlib-static/libiberty-dev to gain symbol demangling config/Makefile:556: No liblzma found, disables xz kernel module decompression, please install xz-devel/liblzma-dev

  CC       util/abspath.o
  CC       event-parse.o
  CC       fd/array.o
  LD       fd/libapi-in.o
  CC       fs/fs.o
  CC       fs/debugfs.o
  CC       event-plugin.o
  CC       fs/findfs.o
  CC       trace-seq.o
  CC       util/alias.o
  CC       parse-filter.o
  CC       fs/tracefs.o
  CC       util/annotate.o
  LD       fs/libapi-in.o
  LD       libapi-in.o
  AR       libapi.a
  CC       parse-utils.o
  GEN      common-cmds.h
  PERF_VERSION = 4.1.rc8.gca3cfa
  CC       kbuffer-parse.o
  LD       libtraceevent-in.o
  CC       arch/common.o
  LINK     libtraceevent.a
  CC       ui/setup.o
In file included from /build/linux/include/uapi/linux/kernel.h:4:0,
                 from /build/linux/include/linux/cache.h:4,
                 from /build/linux/include/linux/rcupdate.h:37,
                 from /build/linux/tools/perf/util/include/../../../../include/linux/rbtree.h:34,
                 from /build/linux/tools/perf/util/include/linux/rbtree.h:4,
                 from arch/../util/map.h:7,
                 from arch/../util/event.h:8,
                 from arch/../util/session.h:5,
                 from arch/common.h:4,
                 from arch/common.c:3:

/build/linux/include/uapi/linux/sysinfo.h:8:2: error: unknown type name ‘__kernel_long_t’
__kernel_long_t uptime; /* Seconds since boot */
^
/build/linux/include/uapi/linux/sysinfo.h:9:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t loads[3]; /* 1, 5, and 15 minute load averages */
^
/build/linux/include/uapi/linux/sysinfo.h:10:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t totalram; /* Total usable main memory size */
^
/build/linux/include/uapi/linux/sysinfo.h:11:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t freeram; /* Available memory size */
^
/build/linux/include/uapi/linux/sysinfo.h:12:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t sharedram; /* Amount of shared memory */
^
/build/linux/include/uapi/linux/sysinfo.h:13:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t bufferram; /* Memory used by buffers */
^
/build/linux/include/uapi/linux/sysinfo.h:14:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t totalswap; /* Total swap space size */
^
/build/linux/include/uapi/linux/sysinfo.h:15:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t freeswap; /* swap space still available */
^
/build/linux/include/uapi/linux/sysinfo.h:18:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t totalhigh; /* Total high memory size */
^
/build/linux/include/uapi/linux/sysinfo.h:19:2: error: unknown type name ‘__kernel_ulong_t’
__kernel_ulong_t freehigh; /* Available high memory size */
^
/build/linux/include/uapi/linux/sysinfo.h:21:22: error: ‘__kernel_ulong_t’ undeclared here (not in a function)
char _f[20-2*sizeof(__kernel_ulong_t)-sizeof(__u32)]; /* Padding: libc5 uses this.. */
....

Does the patch below make things work?

This fix could go into the modules tree, as this commit came via Rusty.

Stephen, feel free to add:

make -C tools/perf

to the linux-next build tests. It's always supposed to build without failure, in pretty much whatever x86 distro you run your build tests on.

Thanks,

Ingo

===================>

From: Ingo Molnar <[email protected]>
Date: Wed, 17 Jun 2015 11:07:11 +0200
Subject: [PATCH] tools/perf, rbtree: Add RCU wrappers to make rbtree.h usable in user-space

---
 tools/perf/util/include/linux/rcupdate.h | 9 +++++++++
 1 file changed, 9 insertions(+)

new file mode 100644
index 000000000000..3e022dd9a69b
@@ -0,0 +1,9 @@
+#ifndef PERF_LINUX_RCUPDATE_H_
+#define PERF_LINUX_RCUPDATE_H_
+
+/* Simple trivial wrappers for now, we don't use RCU in perf user-space (yet): */
+#define WRITE_ONCE(var, val)			((var) = (val))
+#define rcu_assign_pointer(ptr, val)		WRITE_ONCE(ptr, val)
+
+#endif
+

It does,

Hi Ingo,

OK, I have started doing that, but int order to make it build at all, I have added the patch below to my fixes tree (since the breakage is now in Linus' tree).

This means that it will get a conflict with the tip tree tomorrow, but I will just fix the conflict by using the version from the tip tree. Once the tip tree fixes are sent to Linus, I will drop this patch from my fixes tree.

Cheers,
Stephen Rothwell                    [email protected]

On next linux-next iteration you should be able to just drop your merge conflict resolution, and use the -tip tree as-is with no extra fixups.

Thanks,

Ingo

Hi Ingo,

I dropped the patch I had yesterday and just merged perf-urgent-for-linus from the tip tree into my fixes tree (since I merge my fixes tree immediately on top of Linus' tree and before I try to do any builds). I will drop that merge when Linus takes your pull request.

Cheers,
Stephen Rothwell                    [email protected]