[tip:perfcounters/core] perf_counter tools: remove glib dependency and fix bugs in kerneltop.c, fix poll()

Peter Zijlstra
2009-03-24T10:01:49Z

Commit-ID: afc2a3523fc6664f3713b594daa1857f37ad87df
Gitweb: http://git.kernel.org/tip/afc2a3523fc6664f3713b594daa1857f37ad87df
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Tue, 24 Mar 2009 10:50:24 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 24 Mar 2009 10:56:18 +0100

perf_counter tools: remove glib dependency and fix bugs in kerneltop.c, fix poll()

Paul Mackerras wrote:

> I noticed the poll stuff is bogus - we have a 2D array of struct
> pollfds (MAX_NR_CPUS x MAX_COUNTERS), we fill in a sub-array (with the
> rest being uninitialized, since the array is on the stack) and then
> pass the first nr_cpus elements to poll. Not what we really meant, I
> suspect. :) Not even if we only have one counter, since it's the
> counter dimension that varies fastest.

This should fix the most obvious poll fubar.. not enough to fix the
full problem though..

Reported-by: Paul Mackerras <paulus@samba.org>
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <18888.29986.340328.540512@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
Documentation/perf_counter/kerneltop.c | 11 ++++++-----
1 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/Documentation/perf_counter/kerneltop.c b/Documentation/perf_counter/kerneltop.c
index ea13e4e..7ebde7a 100644
--- a/Documentation/perf_counter/kerneltop.c
+++ b/Documentation/perf_counter/kerneltop.c
@@ -1157,10 +1157,10 @@ static void mmap_read(struct mmap_data *md)

int main(int argc, char *argv[])
{
- struct pollfd event_array[MAX_NR_CPUS][MAX_COUNTERS];
+ struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
struct perf_counter_hw_event hw_event;
- int i, counter, group_fd;
+ int i, counter, group_fd, nr_poll = 0;
unsigned int cpu;
int ret;

@@ -1214,8 +1214,9 @@ int main(int argc, char *argv[])
if (group && group_fd == -1)
group_fd = fd[i][counter];

- event_array[i][counter].fd = fd[i][counter];
- event_array[i][counter].events = POLLIN;
+ event_array[nr_poll].fd = fd[i][counter];
+ event_array[nr_poll].events = POLLIN;
+ nr_poll++;

mmap_array[i][counter].counter = counter;
mmap_array[i][counter].prev = 0;
@@ -1247,7 +1248,7 @@ int main(int argc, char *argv[])
}

if (hits == events)
- ret = poll(event_array[0], nr_cpus, 1000);
+ ret = poll(event_array, nr_poll, 1000);
hits = events;
}