From 8dc58101f2c838355d44402aa77646649d10dbec Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 1 Apr 2010 23:59:15 -0500 Subject: perf: Add pipe-specific header read/write and event processing code This patch makes several changes to allow the perf event stream to be sent and received over a pipe: - adds pipe-specific versions of the header read/write code - adds pipe-specific version of the event processing code - adds a range of event types to be used for header or other pseudo events, above the range used by the kernel - checks the return value of event handlers, which they can use to skip over large events during event processing rather than actually reading them into event objects. - unifies the multiple do_read() functions and updates its users. Note that none of these changes affect the existing perf data file format or processing - this code only comes into play if perf output is sent to stdout (or is read from stdin). Signed-off-by: Tom Zanussi Acked-by: Thomas Gleixner Cc: fweisbec@gmail.com Cc: rostedt@goodmis.org Cc: k-keiichi@bx.jp.nec.com Cc: acme@ghostprotocols.net LKML-Reference: <1270184365-8281-2-git-send-email-tzanussi@gmail.com> Signed-off-by: Ingo Molnar --- tools/perf/util/header.c | 78 +++++++++++++++++++++++++++++++++++++----------- 1 file changed, 60 insertions(+), 18 deletions(-) (limited to 'tools/perf/util/header.c') diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 6c9aa16ee51f..8d05337d1a59 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -427,6 +427,25 @@ out_free: return err; } +int perf_header__write_pipe(int fd) +{ + struct perf_pipe_file_header f_header; + int err; + + f_header = (struct perf_pipe_file_header){ + .magic = PERF_MAGIC, + .size = sizeof(f_header), + }; + + err = do_write(fd, &f_header, sizeof(f_header)); + if (err < 0) { + pr_debug("failed to write perf pipe header\n"); + return err; + } + + return 0; +} + int perf_header__write(struct perf_header *self, int fd, bool at_exit) { struct perf_file_header f_header; @@ -518,25 +537,10 @@ int perf_header__write(struct perf_header *self, int fd, bool at_exit) return 0; } -static int do_read(int fd, void *buf, size_t size) -{ - while (size) { - int ret = read(fd, buf, size); - - if (ret <= 0) - return -1; - - size -= ret; - buf += ret; - } - - return 0; -} - static int perf_header__getbuffer64(struct perf_header *self, int fd, void *buf, size_t size) { - if (do_read(fd, buf, size)) + if (do_read(fd, buf, size) <= 0) return -1; if (self->needs_swap) @@ -592,7 +596,7 @@ int perf_file_header__read(struct perf_file_header *self, { lseek(fd, 0, SEEK_SET); - if (do_read(fd, self, sizeof(*self)) || + if (do_read(fd, self, sizeof(*self)) <= 0 || memcmp(&self->magic, __perf_magic, sizeof(self->magic))) return -1; @@ -662,13 +666,51 @@ static int perf_file_section__process(struct perf_file_section *self, return 0; } -int perf_header__read(struct perf_header *self, int fd) +static int perf_file_header__read_pipe(struct perf_pipe_file_header *self, + struct perf_header *ph, int fd) { + if (do_read(fd, self, sizeof(*self)) <= 0 || + memcmp(&self->magic, __perf_magic, sizeof(self->magic))) + return -1; + + if (self->size != sizeof(*self)) { + u64 size = bswap_64(self->size); + + if (size != sizeof(*self)) + return -1; + + ph->needs_swap = true; + } + + return 0; +} + +static int perf_header__read_pipe(struct perf_session *session, int fd) +{ + struct perf_header *self = &session->header; + struct perf_pipe_file_header f_header; + + if (perf_file_header__read_pipe(&f_header, self, fd) < 0) { + pr_debug("incompatible file format\n"); + return -EINVAL; + } + + session->fd = fd; + + return 0; +} + +int perf_header__read(struct perf_session *session, int fd) +{ + struct perf_header *self = &session->header; struct perf_file_header f_header; struct perf_file_attr f_attr; u64 f_id; int nr_attrs, nr_ids, i, j; + if (session->fd_pipe) + return perf_header__read_pipe(session, fd); + if (perf_file_header__read(&f_header, self, fd) < 0) { pr_debug("incompatible file format\n"); return -EINVAL; -- cgit v1.2.3