From: Masami Hiramatsu <mhira...@kernel.org> Introduce perf_cache object and interfaces to create, add entries, commit, and delete the object.
perf_cache represents a file for the cached "perf probe" definitions on one binary file or vmlinux which has its own build id. The probe cache file is located under the build-id cache directory of the target binary, as below; <perf-debug-dir>/.build-id/<BU>/<ILDID>/probe Signed-off-by: Masami Hiramatsu <mhira...@kernel.org> Signed-off-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com> Cc: Ananth N Mavinakayanahalli <ana...@linux.vnet.ibm.com> Cc: Brendan Gregg <brendan.d.gr...@gmail.com> Cc: Hemant Kumar <hem...@linux.vnet.ibm.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Link: http://lkml.kernel.org/r/20160615032830.31330.84998.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/probe-file.c | 331 +++++++++++++++++++++++++++++++++++++++++++ tools/perf/util/probe-file.h | 20 +++ 2 files changed, 351 insertions(+) diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c index 3fe6214970e6..25a40427003e 100644 --- a/tools/perf/util/probe-file.c +++ b/tools/perf/util/probe-file.c @@ -14,6 +14,7 @@ * GNU General Public License for more details. * */ +#include <sys/uio.h> #include "util.h" #include "event.h" #include "strlist.h" @@ -324,3 +325,333 @@ int probe_file__del_events(int fd, struct strfilter *filter) return ret; } + +/* Caller must ensure to remove this entry from list */ +static void probe_cache_entry__delete(struct probe_cache_entry *entry) +{ + if (entry) { + BUG_ON(!list_empty(&entry->node)); + + strlist__delete(entry->tevlist); + clear_perf_probe_event(&entry->pev); + zfree(&entry->spev); + free(entry); + } +} + +static struct probe_cache_entry * +probe_cache_entry__new(struct perf_probe_event *pev) +{ + struct probe_cache_entry *entry = zalloc(sizeof(*entry)); + + if (entry) { + INIT_LIST_HEAD(&entry->node); + entry->tevlist = strlist__new(NULL, NULL); + if (!entry->tevlist) + zfree(&entry); + else if (pev) { + entry->spev = synthesize_perf_probe_command(pev); + if (!entry->spev || + perf_probe_event__copy(&entry->pev, pev) < 0) { + probe_cache_entry__delete(entry); + return NULL; + } + } + } + + return entry; +} + +/* For the kernel probe caches, pass target = NULL */ +static int probe_cache__open(struct probe_cache *pcache, const char *target) +{ + char cpath[PATH_MAX]; + char sbuildid[SBUILD_ID_SIZE]; + char *dir_name; + bool is_kallsyms = !target; + int ret, fd; + + if (target) + ret = filename__sprintf_build_id(target, sbuildid); + else { + target = DSO__NAME_KALLSYMS; + ret = sysfs__sprintf_build_id("/", sbuildid); + } + if (ret < 0) { + pr_debug("Failed to get build-id from %s.\n", target); + return ret; + } + + /* If we have no buildid cache, make it */ + if (!build_id_cache__cached(sbuildid)) { + ret = build_id_cache__add_s(sbuildid, target, + is_kallsyms, NULL); + if (ret < 0) { + pr_debug("Failed to add build-id cache: %s\n", target); + return ret; + } + } + + dir_name = build_id_cache__cachedir(sbuildid, target, is_kallsyms, + false); + if (!dir_name) + return -ENOMEM; + + snprintf(cpath, PATH_MAX, "%s/probes", dir_name); + fd = open(cpath, O_CREAT | O_RDWR, 0644); + if (fd < 0) + pr_debug("Failed to open cache(%d): %s\n", fd, cpath); + free(dir_name); + pcache->fd = fd; + + return fd; +} + +static int probe_cache__load(struct probe_cache *pcache) +{ + struct probe_cache_entry *entry = NULL; + char buf[MAX_CMDLEN], *p; + int ret = 0; + FILE *fp; + + fp = fdopen(dup(pcache->fd), "r"); + if (!fp) + return -EINVAL; + + while (!feof(fp)) { + if (!fgets(buf, MAX_CMDLEN, fp)) + break; + p = strchr(buf, '\n'); + if (p) + *p = '\0'; + if (buf[0] == '#') { /* #perf_probe_event */ + entry = probe_cache_entry__new(NULL); + if (!entry) { + ret = -ENOMEM; + goto out; + } + entry->spev = strdup(buf + 1); + if (entry->spev) + ret = parse_perf_probe_command(buf + 1, + &entry->pev); + else + ret = -ENOMEM; + if (ret < 0) { + probe_cache_entry__delete(entry); + goto out; + } + list_add_tail(&entry->node, &pcache->entries); + } else { /* trace_probe_event */ + if (!entry) { + ret = -EINVAL; + goto out; + } + strlist__add(entry->tevlist, buf); + } + } +out: + fclose(fp); + return ret; +} + +static struct probe_cache *probe_cache__alloc(void) +{ + struct probe_cache *pcache = zalloc(sizeof(*pcache)); + + if (pcache) { + INIT_LIST_HEAD(&pcache->entries); + pcache->fd = -EINVAL; + } + return pcache; +} + +void probe_cache__purge(struct probe_cache *pcache) +{ + struct probe_cache_entry *entry, *n; + + list_for_each_entry_safe(entry, n, &pcache->entries, node) { + list_del_init(&entry->node); + probe_cache_entry__delete(entry); + } +} + +void probe_cache__delete(struct probe_cache *pcache) +{ + if (!pcache) + return; + + probe_cache__purge(pcache); + if (pcache->fd > 0) + close(pcache->fd); + free(pcache); +} + +struct probe_cache *probe_cache__new(const char *target) +{ + struct probe_cache *pcache = probe_cache__alloc(); + int ret; + + if (!pcache) + return NULL; + + ret = probe_cache__open(pcache, target); + if (ret < 0) { + pr_debug("Cache open error: %d\n", ret); + goto out_err; + } + + ret = probe_cache__load(pcache); + if (ret < 0) { + pr_debug("Cache read error: %d\n", ret); + goto out_err; + } + + return pcache; + +out_err: + probe_cache__delete(pcache); + return NULL; +} + +static bool streql(const char *a, const char *b) +{ + if (a == b) + return true; + + if (!a || !b) + return false; + + return !strcmp(a, b); +} + +static struct probe_cache_entry * +probe_cache__find(struct probe_cache *pcache, struct perf_probe_event *pev) +{ + struct probe_cache_entry *entry = NULL; + char *cmd = synthesize_perf_probe_command(pev); + + if (!cmd) + return NULL; + + list_for_each_entry(entry, &pcache->entries, node) { + /* Hit if same event name or same command-string */ + if ((pev->event && + (streql(entry->pev.group, pev->group) && + streql(entry->pev.event, pev->event))) || + (!strcmp(entry->spev, cmd))) + goto found; + } + entry = NULL; + +found: + free(cmd); + return entry; +} + +int probe_cache__add_entry(struct probe_cache *pcache, + struct perf_probe_event *pev, + struct probe_trace_event *tevs, int ntevs) +{ + struct probe_cache_entry *entry = NULL; + char *command; + int i, ret = 0; + + if (!pcache || !pev || !tevs || ntevs <= 0) { + ret = -EINVAL; + goto out_err; + } + + /* Remove old cache entry */ + entry = probe_cache__find(pcache, pev); + if (entry) { + list_del_init(&entry->node); + probe_cache_entry__delete(entry); + } + + ret = -ENOMEM; + entry = probe_cache_entry__new(pev); + if (!entry) + goto out_err; + + for (i = 0; i < ntevs; i++) { + if (!tevs[i].point.symbol) + continue; + + command = synthesize_probe_trace_command(&tevs[i]); + if (!command) + goto out_err; + strlist__add(entry->tevlist, command); + free(command); + } + list_add_tail(&entry->node, &pcache->entries); + pr_debug("Added probe cache: %d\n", ntevs); + return 0; + +out_err: + pr_debug("Failed to add probe caches\n"); + probe_cache_entry__delete(entry); + return ret; +} + +static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd) +{ + struct str_node *snode; + struct stat st; + struct iovec iov[3]; + int ret; + /* Save stat for rollback */ + ret = fstat(fd, &st); + if (ret < 0) + return ret; + + pr_debug("Writing cache: #%s\n", entry->spev); + iov[0].iov_base = (void *)"#"; iov[0].iov_len = 1; + iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev); + iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1; + ret = writev(fd, iov, 3); + if (ret < (int)iov[1].iov_len + 2) + goto rollback; + + strlist__for_each(snode, entry->tevlist) { + iov[0].iov_base = (void *)snode->s; + iov[0].iov_len = strlen(snode->s); + iov[1].iov_base = (void *)"\n"; iov[1].iov_len = 1; + ret = writev(fd, iov, 2); + if (ret < (int)iov[0].iov_len + 1) + goto rollback; + } + return 0; + +rollback: + /* Rollback to avoid cache file corruption */ + if (ret > 0) + ret = -1; + if (ftruncate(fd, st.st_size) < 0) + ret = -2; + + return ret; +} + +int probe_cache__commit(struct probe_cache *pcache) +{ + struct probe_cache_entry *entry; + int ret = 0; + + /* TBD: if we do not update existing entries, skip it */ + ret = lseek(pcache->fd, 0, SEEK_SET); + if (ret < 0) + goto out; + + ret = ftruncate(pcache->fd, 0); + if (ret < 0) + goto out; + + list_for_each_entry(entry, &pcache->entries, node) { + ret = probe_cache_entry__write(entry, pcache->fd); + pr_debug("Cache committed: %d\n", ret); + if (ret < 0) + break; + } +out: + return ret; +} diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h index 18ac9cf51c34..d872e3df7e59 100644 --- a/tools/perf/util/probe-file.h +++ b/tools/perf/util/probe-file.h @@ -5,6 +5,19 @@ #include "strfilter.h" #include "probe-event.h" +/* Cache of probe definitions */ +struct probe_cache_entry { + struct list_head node; + struct perf_probe_event pev; + char *spev; + struct strlist *tevlist; +}; + +struct probe_cache { + int fd; + struct list_head entries; +}; + #define PF_FL_UPROBE 1 #define PF_FL_RW 2 @@ -18,5 +31,12 @@ int probe_file__get_events(int fd, struct strfilter *filter, struct strlist *plist); int probe_file__del_strlist(int fd, struct strlist *namelist); +struct probe_cache *probe_cache__new(const char *target); +int probe_cache__add_entry(struct probe_cache *pcache, + struct perf_probe_event *pev, + struct probe_trace_event *tevs, int ntevs); +int probe_cache__commit(struct probe_cache *pcache); +void probe_cache__purge(struct probe_cache *pcache); +void probe_cache__delete(struct probe_cache *pcache); #endif -- 2.5.5
