Thanks, looks good.
Ethan
On Wed, Jun 27, 2012 at 11:25 AM, Ben Pfaff <b...@nicira.com> wrote:
> Writes to regular files under Unix-like kernels, including Linux, typically
> block until the write is complete, regardless of O_NONBLOCK. When the I/O
> subsystem is busy, this can cause indefinite delays. We have actually
> observed "write" calls sleep for 5 seconds or more for this reason.
>
> Delegating to a subprocess through the worker mechanism should solve the
> problem.
>
> Signed-off-by: Ben Pfaff <b...@nicira.com>
> ---
> lib/vlog.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 files changed, 51 insertions(+), 1 deletions(-)
>
> diff --git a/lib/vlog.c b/lib/vlog.c
> index bcfec7b..d2dc287 100644
> --- a/lib/vlog.c
> +++ b/lib/vlog.c
> @@ -30,11 +30,13 @@
> #include <unistd.h>
> #include "dirs.h"
> #include "dynamic-string.h"
> +#include "ofpbuf.h"
> #include "sat-math.h"
> #include "svec.h"
> #include "timeval.h"
> #include "unixctl.h"
> #include "util.h"
> +#include "worker.h"
>
> VLOG_DEFINE_THIS_MODULE(vlog);
>
> @@ -94,6 +96,8 @@ static void format_log_message(const struct vlog_module *,
> enum vlog_level,
> enum vlog_facility, unsigned int msg_num,
> const char *message, va_list, struct ds *)
> PRINTF_FORMAT(5, 0);
> +static void vlog_write_file(struct ds *);
> +static void vlog_update_async_log_fd(void);
>
> /* Searches the 'n_names' in 'names'. Returns the index of a match for
> * 'target', or 'n_names' if no name matches. */
> @@ -298,6 +302,9 @@ vlog_set_log_file(const char *file_name)
> /* Open new log file and update min_levels[] to reflect whether we
> actually
> * have a log_file. */
> log_fd = open(log_file_name, O_WRONLY | O_CREAT | O_APPEND, 0666);
> + if (log_fd >= 0) {
> + vlog_update_async_log_fd();
> + }
> for (mp = vlog_modules; mp < &vlog_modules[n_vlog_modules]; mp++) {
> update_min_level(*mp);
> }
> @@ -726,7 +733,7 @@ vlog_valist(const struct vlog_module *module, enum
> vlog_level level,
> format_log_message(module, level, VLF_FILE, msg_num,
> message, args, &s);
> ds_put_char(&s, '\n');
> - write(log_fd, s.string, s.length);
> + vlog_write_file(&s);
> }
>
> ds_destroy(&s);
> @@ -871,3 +878,46 @@ vlog_usage(void)
> " (default: %s/%s.log)\n",
> ovs_logdir(), program_name);
> }
> +
> +static bool vlog_async_inited = false;
> +
> +static worker_request_func vlog_async_write_request_cb;
> +
> +static void
> +vlog_write_file(struct ds *s)
> +{
> + if (worker_is_running()) {
> + worker_request(s->string, s->length,
> + &log_fd, vlog_async_inited ? 0 : 1,
> + vlog_async_write_request_cb, NULL, NULL);
> + vlog_async_inited = true;
> + } else {
> + write(log_fd, s->string, s->length);
> + }
> +}
> +
> +static void
> +vlog_update_async_log_fd(void)
> +{
> + if (worker_is_running()) {
> + worker_request(NULL, 0, &log_fd, 1, vlog_async_write_request_cb,
> + NULL, NULL);
> + vlog_async_inited = true;
> + }
> +}
> +
> +static void
> +vlog_async_write_request_cb(struct ofpbuf *request,
> + const int *fd, size_t n_fds)
> +{
> + if (n_fds > 0) {
> + if (log_fd >= 0) {
> + close(log_fd);
> + }
> + log_fd = *fd;
> + }
> +
> + if (request->size > 0) {
> + write(log_fd, request->data, request->size);
> + }
> +}
> --
> 1.7.2.5
>
> _______________________________________________
> dev mailing list
> dev@openvswitch.org
> http://openvswitch.org/mailman/listinfo/dev
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
