BMC/Intel-BMC/linux.git/tools/perf/util/build-id.c, branch dev

perf machine: No need to have two DSOs lists

2015-05-29T15:43:43+00:00

We can, given a DSO, figure out if it is a kernel, a kernel module or a userlevel DSO, so stop having to process two lists in several functions. If searching becomes an issue at some point, we can have them in a rbtree, etc. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-s4yb0onpdywu6dj2xl9lxi4t@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Protect the machine->threads with a rwlock

2015-05-08T19:19:27+00:00

In addition to using refcounts for the struct thread lifetime management, we need to protect access to machine->threads from concurrent access. That happens in 'perf top', where a thread processes events, inserting and deleting entries from that rb_tree while another thread decays hist_entries, that end up dropping references and ultimately deleting threads from the rb_tree and releasing its resources when no further hist_entry (or other data structures, like in 'perf sched') references it. So the rule is the same for refcounts + protected trees in the kernel, get the tree lock, find object, bump the refcount, drop the tree lock, return, use object, drop the refcount if no more use of it is needed, keep it if storing it in some other data structure, drop when releasing that data structure. I.e. pair "t = machine__find(new)_thread()" with a "thread__put(t)", and "perf_event__preprocess_sample(&al)" with "addr_location__put(&al)". The addr_location__put() one is because as we return references to several data structures, we may end up adding more reference counting for the other data structures and then we'll drop it at addr_location__put() time. Acked-by: David Ahern Cc: Adrian Hunter Cc: Borislav Petkov Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-bs9rt4n0jw3hi9f3zxyy3xln@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-list: Fix segfault when show DSOs with hits

2015-04-10T13:13:59+00:00

commit: f3b623b8490a ("perf tools: Reference count struct thread") appends every thread->node to dead_threads in machine__remove_thread() and list_del_init() this node in thread__put(). perf_event__exit_del_thread() releases thread wihout using machine__remove_thread(), and causes a NULL pointer crash when list_del_init(&thread->node) is called. Fix this by using machine_remove_thread() instead of using thread__put() directly. This problem can be reproduced as following: $ perf record ls $ perf buildid-list --with-hits [ 3874.195070] perf[1018]: segfault at 0 ip 00000000004b0b15 sp 00007ffc35b44780 error 6 in perf[400000+166000] Segmentation fault After this patch: $ perf record ls $ perf buildid-list --with-hits bc23e7c3281e542650ba4324421d6acf78f4c23e /proc/kcore 643324cb0e969f30c56d660f167f84a150845511 [vdso] 0000000000000000000000000000000000000000 /bin/busybox ... Signed-off-by: He Kuang Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/1428658500-6483-1-git-send-email-hekuang@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix race in build_id_cache__add_s()

2015-03-20T20:49:50+00:00

int build_id_cache__add_s(const char *sbuild_id, const char *debugdir, const char *name, bool is_kallsyms, bool is_vdso) { ... if (access(filename, F_OK)) { ^--------------------------------------------------------- [1] if (is_kallsyms) { if (copyfile("/proc/kallsyms", filename)) goto out_free; } else if (link(realname, filename) && copyfile(name, filename)) ^-----------------------------^------------- [2] \------------ [3] goto out_free; } ... When multiple instances of perf record get to [1] at more or less same time and run access() one or more may get failure because the file does not exist yet (since the first instance did not have chance to link it yet). At this point the race moves to link() at [2] where first thread to get there links file and goes on but second one gets -EEXIST so it runs copyfile [3] which truncates the file. reproducer: rm -rf /root/.debug for cpu in $(awk '/processor/ {print $3}' /proc/cpuinfo); do perf record -a -v -T -F 1000 -C $cpu \ -o perf-${cpu}.data sleep 5 2> /dev/null & done wait and simply search for empty files by: find /lib/modules/`uname -r`/kernel/* -size 0 Signed-off-by: Milos Vyletel Acked-by: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1426847846-11112-1-git-send-email-milos@redhat.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Reference count struct thread

2015-03-03T03:17:08+00:00

We need to do that to stop accumulating entries in the dead_threads linked list, i.e. we were keeping references to threads in struct hists that continue to exist even after a thread exited and was removed from the machine threads rbtree. We still keep the dead_threads list, but just for debugging, allowing us to iterate at any given point over the threads that still are referenced by things like struct hist_entry. Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-3ejvfyed0r7ue61dkurzjux4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Add --purge FILE to remove all caches of FILE

2015-02-27T18:52:33+00:00

Add --purge FILE to remove all caches of FILE. Since the current --remove FILE removes a cache which has same build-id of given FILE. Since the command takes a FILE path, it can confuse user who tries to remove cache about FILE path. ----- # ./perf buildid-cache -v --add ./perf Adding 133b7b5486d987a5ab5c3ebf4ea14941f45d4d4f ./perf: Ok # (update the ./perf binary) # ./perf buildid-cache -v --remove ./perf Removing 305bbd1be68f66eca7e2d78db294653031edfa79 ./perf: FAIL ./perf wasn't in the cache ----- Actually, the --remove's FAIL is not shown, it just silently fails. So, this patch adds --purge FILE action for such usecase. perf buildid-cache --purge FILE removes all caches which has same FILE path. In other words, it removes all caches including old binaries. ----- # ./perf buildid-cache -v --add ./perf Adding 133b7b5486d987a5ab5c3ebf4ea14941f45d4d4f ./perf: Ok # (update the ./perf binary) # ./perf buildid-cache -v --purge ./perf Removing 133b7b5486d987a5ab5c3ebf4ea14941f45d4d4f ./perf: Ok ----- BTW, if you want to purge all the caches, remove ~/.debug/* . Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Borislav Petkov Cc: Hemant Kumar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150227045026.1999.64084.stgit@localhost.localdomain [ s/dirname/dir_name/g to fix build on fedora14, where dirname is a global ] Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Add new buildid cache if update target is not cached

2015-02-27T13:08:37+00:00

Add new buildid cache if the update target file is not cached. This can happen when an old binary is replaced by new one after caching the old one. In this case, user sees his operation just failed. But it does not look straight, since user just pass the binary "path", not "build-id". ---- # ./perf buildid-cache --add ./perf (update ./perf to new binary) # ./perf buildid-cache --update ./perf ./perf wasn't in the cache # ---- This patch adds given new binary to cache if the new binary is not cached. So we'll not see the above error. ---- # ./perf buildid-cache --add ./perf (update ./perf to new binary) # ./perf buildid-cache --update ./perf # ---- Signed-off-by: Masami Hiramatsu Cc: Adrian Hunter Cc: Borislav Petkov Cc: Hemant Kumar Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150226065440.23912.1494.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Consolidate .build-id cache path generators

2015-02-11T15:37:33+00:00

Consolidate .build-id cache path generating routines to build_id__filename() function. Other functions must use it to get the buildid cache path (link path) from build-id. This can reduce the risk of partial-update. Signed-off-by: Masami Hiramatsu Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Borislav Petkov Cc: Hemant Kumar Cc: Jiri Olsa Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150210091853.19264.58513.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Remove unneeded debugdir parameters

2015-02-11T15:37:33+00:00

Functions related to buildid-cache subcommand use debugdir parameters for passing buildid cache directory path. However all callers just pass buildid_dir global variable. Moreover, other functions which refer buildid cache use buildid_dir directly. This removes unneeded debugdir parameters from those functions and use buildid_dir if needed. Signed-off-by: Masami Hiramatsu Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Borislav Petkov Cc: Hemant Kumar Cc: Jiri Olsa Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20150210091851.19264.72741.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Remove extra debugdir variables

2014-12-09T12:14:34+00:00

There's no need to copy over the buildid_dir into separate variable with no change. This is leftover from commit: 45de34bbe3e1 perf buildid: add perfconfig option to specify buildid cache dir that added global buildid_dir variable that holds cache directory, but did not cleanup the debugdir copies. Signed-off-by: Jiri Olsa Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Steven Rostedt Link: http://lkml.kernel.org/r/1417460789-13874-3-git-send-email-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo