perf session: Cleanup __perf_session__process_events()

Replace the pseudo C++ self argument with session and give the mmap related
variables a sensible name. shift is a complete misnomer - it took me several
rounds of cursing to figure out that it's not a shift value.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163820.029687218@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 525bcf6..2fdbccf 100644 (file)
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -567,13 +567,13 @@ static int perf_session__process_sample(event_t *event, struct perf_session *s,
 static int perf_session__process_event(struct perf_session *self,
                                       event_t *event,
                                       struct perf_event_ops *ops,
-                                      u64 offset, u64 head)
+                                      u64 file_offset)
 {
        trace_event(event);
 
        if (event->header.type < PERF_RECORD_HEADER_MAX) {
                dump_printf("%#Lx [%#x]: PERF_RECORD_%s",
-                           offset + head, event->header.size,
+                           file_offset, event->header.size,
                            event__name[event->header.type]);
                hists__inc_nr_events(&self->hists, event->header.type);
        }
@@ -606,7 +606,7 @@ static int perf_session__process_event(struct perf_session *self,
                return ops->event_type(event, self);
        case PERF_RECORD_HEADER_TRACING_DATA:
                /* setup for reading amidst mmap */
-               lseek(self->fd, offset + head, SEEK_SET);
+               lseek(self->fd, file_offset, SEEK_SET);
                return ops->tracing_data(event, self);
        case PERF_RECORD_HEADER_BUILD_ID:
                return ops->build_id(event, self);
@@ -705,8 +705,7 @@ more:
        }
 
        if (size == 0 ||
-           (skip = perf_session__process_event(self, &event, ops,
-                                               0, head)) < 0) {
+           (skip = perf_session__process_event(self, &event, ops, head)) < 0) {
                dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
                            head, event.header.size, event.header.type);
                /*
@@ -735,19 +734,19 @@ out_err:
        return err;
 }
 
-int __perf_session__process_events(struct perf_session *self,
+int __perf_session__process_events(struct perf_session *session,
                                   u64 data_offset, u64 data_size,
                                   u64 file_size, struct perf_event_ops *ops)
 {
+       u64 head, page_offset, file_offset;
        int err, mmap_prot, mmap_flags;
-       u64 head, shift;
-       u64 offset = 0;
+       struct ui_progress *progress;
        size_t  page_size;
        event_t *event;
        uint32_t size;
        char *buf;
-       struct ui_progress *progress = ui_progress__new("Processing events...",
-                                                       self->size);
+
+       progress = ui_progress__new("Processing events...", session->size);
        if (progress == NULL)
                return -1;
 
@@ -755,21 +754,20 @@ int __perf_session__process_events(struct perf_session *self,
 
        page_size = sysconf(_SC_PAGESIZE);
 
-       head = data_offset;
-       shift = page_size * (head / page_size);
-       offset += shift;
-       head -= shift;
+       page_offset = page_size * (data_offset / page_size);
+       file_offset = page_offset;
+       head = data_offset - page_offset;
 
        mmap_prot  = PROT_READ;
        mmap_flags = MAP_SHARED;
 
-       if (self->header.needs_swap) {
+       if (session->header.needs_swap) {
                mmap_prot  |= PROT_WRITE;
                mmap_flags = MAP_PRIVATE;
        }
 remap:
-       buf = mmap(NULL, page_size * self->mmap_window, mmap_prot,
-                  mmap_flags, self->fd, offset);
+       buf = mmap(NULL, page_size * session->mmap_window, mmap_prot,
+                  mmap_flags, session->fd, file_offset);
        if (buf == MAP_FAILED) {
                pr_err("failed to mmap file\n");
                err = -errno;
@@ -778,36 +776,35 @@ remap:
 
 more:
        event = (event_t *)(buf + head);
-       ui_progress__update(progress, offset);
+       ui_progress__update(progress, file_offset);
 
-       if (self->header.needs_swap)
+       if (session->header.needs_swap)
                perf_event_header__bswap(&event->header);
        size = event->header.size;
        if (size == 0)
                size = 8;
 
-       if (head + event->header.size >= page_size * self->mmap_window) {
+       if (head + event->header.size >= page_size * session->mmap_window) {
                int munmap_ret;
 
-               shift = page_size * (head / page_size);
-
-               munmap_ret = munmap(buf, page_size * self->mmap_window);
+               munmap_ret = munmap(buf, page_size * session->mmap_window);
                assert(munmap_ret == 0);
 
-               offset += shift;
-               head -= shift;
+               page_offset = page_size * (head / page_size);
+               file_offset += page_offset;
+               head -= page_offset;
                goto remap;
        }
 
        size = event->header.size;
 
        dump_printf("\n%#Lx [%#x]: event: %d\n",
-                   offset + head, event->header.size, event->header.type);
+                   file_offset + head, event->header.size, event->header.type);
 
-       if (size == 0 ||
-           perf_session__process_event(self, event, ops, offset, head) < 0) {
+       if (size == 0 || perf_session__process_event(session, event, ops,
+                                                    file_offset + head) < 0) {
                dump_printf("%#Lx [%#x]: skipping unknown header type: %d\n",
-                           offset + head, event->header.size,
+                           file_offset + head, event->header.size,
                            event->header.type);
                /*
                 * assume we lost track of the stream, check alignment, and
@@ -821,36 +818,36 @@ more:
 
        head += size;
 
-       if (offset + head >= data_offset + data_size)
+       if (file_offset + head >= data_offset + data_size)
                goto done;
 
-       if (offset + head < file_size)
+       if (file_offset + head < file_size)
                goto more;
 done:
        err = 0;
        /* do the final flush for ordered samples */
-       self->ordered_samples.next_flush = ULLONG_MAX;
-       flush_sample_queue(self, ops);
+       session->ordered_samples.next_flush = ULLONG_MAX;
+       flush_sample_queue(session, ops);
 out_err:
        ui_progress__delete(progress);
 
        if (ops->lost == event__process_lost &&
-           self->hists.stats.total_lost != 0) {
+           session->hists.stats.total_lost != 0) {
                ui__warning("Processed %Lu events and LOST %Lu!\n\n"
                            "Check IO/CPU overload!\n\n",
-                           self->hists.stats.total_period,
-                           self->hists.stats.total_lost);
+                           session->hists.stats.total_period,
+                           session->hists.stats.total_lost);
        }
-       
-       if (self->hists.stats.nr_unknown_events != 0) {
+
+       if (session->hists.stats.nr_unknown_events != 0) {
                ui__warning("Found %u unknown events!\n\n"
                            "Is this an older tool processing a perf.data "
                            "file generated by a more recent tool?\n\n"
                            "If that is not the case, consider "
                            "reporting to linux-kernel@vger.kernel.org.\n\n",
-                           self->hists.stats.nr_unknown_events);
+                           session->hists.stats.nr_unknown_events);
        }
-               
+
        return err;
 }