| Message ID | 152828901936.9599.10143519677183418086.stgit@alrua-kau |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | [bpf-next,v5,1/2] trace_helpers.c: Add helpers to poll multiple perf FDs for events | expand |
On Wed, 06 Jun 2018 14:43:39 +0200, Toke Høiland-Jørgensen wrote: > Add two new helper functions to trace_helpers that supports polling > multiple perf file descriptors for events. These are used to the XDP > perf_event_output example, which needs to work with one perf fd per CPU. > > Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> malloc() + memset(0) could have been replaced with calloc, but otherwise looks good.
Jakub Kicinski <jakub.kicinski@netronome.com> writes: > On Wed, 06 Jun 2018 14:43:39 +0200, Toke Høiland-Jørgensen wrote: >> Add two new helper functions to trace_helpers that supports polling >> multiple perf file descriptors for events. These are used to the XDP >> perf_event_output example, which needs to work with one perf fd per CPU. >> >> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> > > malloc() + memset(0) could have been replaced with calloc, but > otherwise looks good. Ah right. I'll fix that and your nit for the other patch and resubmit with your reviewed-by tag. Thanks for reviewing!
On Wed, Jun 6, 2018 at 10:51 AM, Toke Høiland-Jørgensen wrote: > Jakub Kicinski <jakub.kicinski@netronome.com> writes: > >> On Wed, 06 Jun 2018 14:43:39 +0200, Toke Høiland-Jørgensen wrote: >>> Add two new helper functions to trace_helpers that supports polling >>> multiple perf file descriptors for events. These are used to the XDP >>> perf_event_output example, which needs to work with one perf fd per CPU. >>> >>> Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> >> >> malloc() + memset(0) could have been replaced with calloc, but >> otherwise looks good. > > Ah right. I'll fix that and your nit for the other patch and resubmit > with your reviewed-by tag. Thanks for reviewing! Thank you :)
diff --git a/tools/testing/selftests/bpf/trace_helpers.c b/tools/testing/selftests/bpf/trace_helpers.c index 3868dcb63420..0673e8840cc8 100644 --- a/tools/testing/selftests/bpf/trace_helpers.c +++ b/tools/testing/selftests/bpf/trace_helpers.c @@ -88,7 +88,7 @@ static int page_size; static int page_cnt = 8; static struct perf_event_mmap_page *header; -int perf_event_mmap(int fd) +int perf_event_mmap_header(int fd, struct perf_event_mmap_page **header) { void *base; int mmap_size; @@ -102,10 +102,15 @@ int perf_event_mmap(int fd) return -1; } - header = base; + *header = base; return 0; } +int perf_event_mmap(int fd) +{ + return perf_event_mmap_header(fd, &header); +} + static int perf_event_poll(int fd) { struct pollfd pfd = { .fd = fd, .events = POLLIN }; @@ -163,3 +168,43 @@ int perf_event_poller(int fd, perf_event_print_fn output_fn) return ret; } + +int perf_event_poller_multi(int *fds, struct perf_event_mmap_page **headers, + int num_fds, perf_event_print_fn output_fn) +{ + enum bpf_perf_event_ret ret; + struct pollfd *pfds; + void *buf = NULL; + size_t len = 0; + int i; + + pfds = malloc(sizeof(*pfds) * num_fds); + if (!pfds) + return LIBBPF_PERF_EVENT_ERROR; + + memset(pfds, 0, sizeof(*pfds) * num_fds); + for (i = 0; i < num_fds; i++) { + pfds[i].fd = fds[i]; + pfds[i].events = POLLIN; + } + + for (;;) { + poll(pfds, num_fds, 1000); + for (i = 0; i < num_fds; i++) { + if (!pfds[i].revents) + continue; + + ret = bpf_perf_event_read_simple(headers[i], + page_cnt * page_size, + page_size, &buf, &len, + bpf_perf_event_print, + output_fn); + if (ret != LIBBPF_PERF_EVENT_CONT) + break; + } + } + free(buf); + free(pfds); + + return ret; +} diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index 3b4bcf7f5084..18924f23db1b 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -3,6 +3,7 @@ #define __TRACE_HELPER_H #include <libbpf.h> +#include <linux/perf_event.h> struct ksym { long addr; @@ -16,6 +17,9 @@ long ksym_get_addr(const char *name); typedef enum bpf_perf_event_ret (*perf_event_print_fn)(void *data, int size); int perf_event_mmap(int fd); +int perf_event_mmap_header(int fd, struct perf_event_mmap_page **header); /* return LIBBPF_PERF_EVENT_DONE or LIBBPF_PERF_EVENT_ERROR */ int perf_event_poller(int fd, perf_event_print_fn output_fn); +int perf_event_poller_multi(int *fds, struct perf_event_mmap_page **headers, + int num_fds, perf_event_print_fn output_fn); #endif
Add two new helper functions to trace_helpers that supports polling multiple perf file descriptors for events. These are used to the XDP perf_event_output example, which needs to work with one perf fd per CPU. Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> --- tools/testing/selftests/bpf/trace_helpers.c | 49 ++++++++++++++++++++++++++- tools/testing/selftests/bpf/trace_helpers.h | 4 ++ 2 files changed, 51 insertions(+), 2 deletions(-)