linux.git/tools/perf/util/machine.c, branch v5.5-rc2

perf maps: Rename 'mg' variables to 'maps'

2019-11-26T14:07:46+00:00

Continuing the merge of 'struct maps' with 'struct map_groups'.

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-z8d14wrw393a0fbvmnk1bqd9@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf map_symbol: Rename ms->mg to ms->maps

2019-11-26T14:07:46+00:00

One more step on the merge of 'struct maps' with 'struct map_groups'.

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-61rra2wg392rhvdgw421wzpt@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf addr_location: Rename al->mg to al->maps

2019-11-26T14:07:46+00:00

One more step on the merge of 'struct maps' with 'struct map_groups'.

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-foo95pyyp3bhocbt7yd8qrvq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Rename thread->mg to thread->maps

2019-11-26T14:07:46+00:00

One more step on the merge of 'struct maps' with 'struct map_groups'.

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-69vcr8pubpym90skxhmbwhiw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf maps: Merge 'struct maps' with 'struct map_groups'

2019-11-26T14:07:46+00:00

And pick the shortest name: 'struct maps'.

The split existed because we used to have two groups of maps, one for
functions and one for variables, but that only complicated things,
sometimes we needed to figure out what was at some address and then had
to first try it on the functions group and if that failed, fall back to
the variables one.

That split is long gone, so for quite a while we had only one struct
maps per struct map_groups, simplify things by combining those structs.

First patch is the minimum needed to merge both, follow up patches will
rename 'thread->mg' to 'thread->maps', etc.

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-hom6639ro7020o708trhxh59@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf dso: Move dso_id from 'struct map' to 'struct dso'

2019-11-19T22:12:26+00:00

And take it into account when looking up DSOs when we have the dso_id
fields obtained from somewhere, like from PERF_RECORD_MMAP2 records.

Instances of struct map pointing to the same DSO pathname but with
anything in dso_id different are in fact different DSOs, so better have
different 'struct dso' instances to reflect that. At some point we may
want to get copies of the contents of the different objects if we want
to do correct annotation or other analysis.

With this we get 'struct map' 24 bytes leaner:

  $ pahole -C map ~/bin/perf
  struct map {
  	union {
  		struct rb_node     rb_node __attribute__((__aligned__(8))); /*     0    24 */
  		struct list_head   node;                 /*     0    16 */
  	} __attribute__((__aligned__(8)));               /*     0    24 */
  	u64                        start;                /*    24     8 */
  	u64                        end;                  /*    32     8 */
  	_Bool                      erange_warned:1;      /*    40: 0  1 */
  	_Bool                      priv:1;               /*    40: 1  1 */

  	/* XXX 6 bits hole, try to pack */
  	/* XXX 3 bytes hole, try to pack */

  	u32                        prot;                 /*    44     4 */
  	u64                        pgoff;                /*    48     8 */
  	u64                        reloc;                /*    56     8 */
  	/* --- cacheline 1 boundary (64 bytes) --- */
  	u64                        (*map_ip)(struct map *, u64); /*    64     8 */
  	u64                        (*unmap_ip)(struct map *, u64); /*    72     8 */
  	struct dso *               dso;                  /*    80     8 */
  	refcount_t                 refcnt;               /*    88     4 */
  	u32                        flags;                /*    92     4 */

  	/* size: 96, cachelines: 2, members: 13 */
  	/* sum members: 92, holes: 1, sum holes: 3 */
  	/* sum bitfield members: 2 bits, bit holes: 1, sum bit holes: 6 bits */
  	/* forced alignments: 1 */
  	/* last cacheline: 32 bytes */
  } __attribute__((__aligned__(8)));
  $

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-g4hxxmraplo7wfjmk384mfsb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Pass a dso_id to map__new()

2019-11-19T18:09:26+00:00

Instead of the 4 fields, a step in the direction of moving this to
struct dso.

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-gp5s1xgxacurmih5d1l94ymy@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf callchain: Fix segfault in thread__resolve_callchain_sample()

2019-11-18T16:01:59+00:00

Do not dereference 'chain' when it is NULL.

  $ perf record -e intel_pt//u -e branch-misses:u uname
  $ perf report --itrace=l --branch-history
  perf: Segmentation fault

Fixes: e9024d519d89 ("perf callchain: Honour the ordering of PERF_CONTEXT_{USER,KERNEL,etc}")
Signed-off-by: Adrian Hunter 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Link: http://lore.kernel.org/lkml/20191114142538.4097-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: No need to check if kernel module maps pre-exist

2019-11-18T16:01:50+00:00

We'only populating maps for kernel modules either from perf.data file
PERF_RECORD_MMAP records or when parsing /proc/modules, so there is no
need to first look if we already have those module maps in the list,
that would mean the kernel has duplicate entries.

So ditch one use of looking up maps by name.

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-gnzjg2hhuz6jnrw91m35059y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf map: No need to adjust the long name of modules

2019-11-18T14:21:32+00:00

At some point in the past we needed to make sure we would get the long
name of modules and not just what we get from /proc/modules, but that
need, as described in the cset that introduced the adjustment function:

Fixes: c03d5184f0e9 ("perf machine: Adjust dso->long_name for offline module")

Without using the buildid-cache:

  # lsmod | grep trusted
  # insmod trusted.ko
  # lsmod | grep trusted
  trusted                24576  0
  # strace -e open,openat perf probe -m ./trusted.ko key_seal |& grep trusted
  openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 4
  openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 7
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/.debug/root/trusted.ko/dd3d355d567394d540f527e093e0f64b95879584/probes", O_RDWR|O_CREAT, 0644) = 3
  openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/.debug/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, ".debug/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 4
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
    probe:key_seal       (on key_seal in trusted)
  # perf probe -l
    probe:key_seal       (on key_seal in trusted)
  #

No attempt at opening '[trusted]'.

Now using the build-id cache:

  # rmmod trusted
  # perf buildid-cache --add ./trusted.ko
  # insmod trusted.ko
  # strace -e open,openat perf probe -m ./trusted.ko key_seal |& grep trusted
  openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 4
  openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 7
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/.debug/root/trusted.ko/dd3d355d567394d540f527e093e0f64b95879584/probes", O_RDWR|O_CREAT, 0644) = 3
  openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/.debug/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, ".debug/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 4
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  #

Again, no attempt at reading '[trusted]'.

Finally, adding a probe to that function and then using:

[root@quaco ~]# perf trace -e probe_perf:*/max-stack=16/ --max-events=2
     0.000 perf/13456 probe_perf:dso__adjust_kmod_long_name(__probe_ip: 5492263)
                                       dso__adjust_kmod_long_name (/home/acme/bin/perf)
                                       machine__process_kernel_mmap_event (/home/acme/bin/perf)
                                       machine__process_mmap_event (/home/acme/bin/perf)
                                       perf_event__process_mmap (/home/acme/bin/perf)
                                       machines__deliver_event (/home/acme/bin/perf)
                                       perf_session__deliver_event (/home/acme/bin/perf)
                                       perf_session__process_event (/home/acme/bin/perf)
                                       process_simple (/home/acme/bin/perf)
                                       reader__process_events (/home/acme/bin/perf)
                                       __perf_session__process_events (/home/acme/bin/perf)
                                       perf_session__process_events (/home/acme/bin/perf)
                                       process_buildids (/home/acme/bin/perf)
                                       record__finish_output (/home/acme/bin/perf)
                                       __cmd_record (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
     0.055 perf/13456 probe_perf:dso__adjust_kmod_long_name(__probe_ip: 5492263)
                                       dso__adjust_kmod_long_name (/home/acme/bin/perf)
                                       machine__process_kernel_mmap_event (/home/acme/bin/perf)
                                       machine__process_mmap_event (/home/acme/bin/perf)
                                       perf_event__process_mmap (/home/acme/bin/perf)
                                       machines__deliver_event (/home/acme/bin/perf)
                                       perf_session__deliver_event (/home/acme/bin/perf)
                                       perf_session__process_event (/home/acme/bin/perf)
                                       process_simple (/home/acme/bin/perf)
                                       reader__process_events (/home/acme/bin/perf)
                                       __perf_session__process_events (/home/acme/bin/perf)
                                       perf_session__process_events (/home/acme/bin/perf)
                                       process_buildids (/home/acme/bin/perf)
                                       record__finish_output (/home/acme/bin/perf)
                                       __cmd_record (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
  #

This was the only path I could find using the perf tools that reach at this
function, then as of november/2019, if we put a probe in the line where the
actuall setting of the dso->long_name is done:

  # perf trace -e probe_perf:*
  ^C[root@quaco ~]
  # perf stat -e probe_perf:*  -I 2000
       2.000404265                  0      probe_perf:dso__adjust_kmod_long_name
       4.001142200                  0      probe_perf:dso__adjust_kmod_long_name
       6.001704120                  0      probe_perf:dso__adjust_kmod_long_name
       8.002398316                  0      probe_perf:dso__adjust_kmod_long_name
      10.002984010                  0      probe_perf:dso__adjust_kmod_long_name
      12.003597851                  0      probe_perf:dso__adjust_kmod_long_name
      14.004113303                  0      probe_perf:dso__adjust_kmod_long_name
      16.004582773                  0      probe_perf:dso__adjust_kmod_long_name
      18.005176373                  0      probe_perf:dso__adjust_kmod_long_name
      20.005801605                  0      probe_perf:dso__adjust_kmod_long_name
      22.006467540                  0      probe_perf:dso__adjust_kmod_long_name
  ^C    23.683261941                  0      probe_perf:dso__adjust_kmod_long_name

  #

Its not being used at all.

To further test this I used kvm.ko as the offline module, i.e. removed
if from the buildid-cache by nuking it completely (rm -rf ~/.debug) and
moved it from the normal kernel distro path, removed the modules, stoped
the kvm guest, and then installed it manually, etc.

  # rmmod kvm-intel
  # rmmod kvm
  # lsmod | grep kvm
  # modprobe kvm-intel
  modprobe: ERROR: ctx=0x55d3b1722260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory
  modprobe: ERROR: ctx=0x55d3b1722260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory
  modprobe: ERROR: could not insert 'kvm_intel': Unknown symbol in module, or unknown parameter (see dmesg)
  # insmod ./kvm.ko
  # modprobe kvm-intel
  modprobe: ERROR: ctx=0x562f34026260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory
  modprobe: ERROR: ctx=0x562f34026260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory
  # lsmod | grep kvm
  kvm_intel             299008  0
  kvm                   765952  1 kvm_intel
  irqbypass              16384  1 kvm
  #
  # perf probe -x ~/bin/perf machine__findnew_module_map:12 mname=m.name:string filename=filename:string 'dso_long_name=map->dso->long_name:string' 'dso_name=map->dso->name:string'
  # perf probe -l
    probe_perf:machine__findnew_module_map (on machine__findnew_module_map:12@util/machine.c in /home/acme/bin/perf with mname filename dso_long_name dso_name)
  # perf record
  ^C[ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 3.416 MB perf.data (33956 samples) ]
  # perf trace -e probe_perf:machine*
  
       6.322 perf/23099 probe_perf:machine__findnew_module_map(__probe_ip: 5492493, mname: "[salsa20_generic]", filename: "/lib/modules/5.3.8-200.fc30.x86_64/kernel/crypto/salsa20_generic.ko.xz", dso_long_name: "/lib/modules/5.3.8-200.fc30.x86_64/kernel/crypto/salsa20_generic.ko.xz", dso_name: "[salsa20_generic]")
       6.375 perf/23099 probe_perf:machine__findnew_module_map(__probe_ip: 5492493, mname: "[kvm]", filename: "[kvm]", dso_long_name: "[kvm]", dso_name: "[kvm]")
  

The filename doesn't come with the path, no point in trying to set the dso->long_name.

  [root@quaco ~]# strace -e open,openat perf probe -m ./kvm.ko kvm_apic_local_deliver |& egrep 'open.*kvm'
  openat(AT_FDCWD, "/sys/module/kvm_intel/notes/.note.gnu.build-id", O_RDONLY) = 4
  openat(AT_FDCWD, "/sys/module/kvm/notes/.note.gnu.build-id", O_RDONLY) = 4
  openat(AT_FDCWD, "/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 7
  openat(AT_FDCWD, "/sys/module/kvm_intel/notes/.note.gnu.build-id", O_RDONLY) = 8
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/.debug/root/kvm.ko/5955f426cb93f03f30f3e876814be2db80ab0b55/probes", O_RDWR|O_CREAT, 0644) = 3
  openat(AT_FDCWD, "/usr/lib/debug/root/kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/usr/lib/debug/root/kvm.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/.debug/kvm.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, ".debug/kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 4
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  [root@quaco ~]#

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-jlfew3lyb24d58egrp0o72o2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo