On Tue, 2016-12-27 at 16:03 +0800, tang.junhui@xxxxxxxxxx wrote:
> From: tang.junhui <tang.junhui@xxxxxxxxxx>
>
> The more uevents are merged, the higher efficiency program will
> performs.
> So, do not process uevents after receiving immediately in uevents
> burst
> situations, but continue wait 1 seconds for more uevents except that
> too
> much uevents (2048) have already been received or too much time
> eclipse
> (60 seconds).
Hi Tang,
thanks for this impressive patch set. While I haven't had time to read
through the more complex parts yet, one small nitpick on this patch:
please use named constants rather than explicit numbers in the code.
Regards,
Martin
>
> Change-Id: I763d491540e8114a81d12d603281540a81502742
> Signed-off-by: tang.junhui <tang.junhui@xxxxxxxxxx>
> ---
> libmultipath/uevent.c | 35 +++++++++++++++++++++++++++++++++--
> 1 file changed, 33 insertions(+), 2 deletions(-)
>
> diff --git a/libmultipath/uevent.c b/libmultipath/uevent.c
> index cc10d65..b0b05e9 100644
> --- a/libmultipath/uevent.c
> +++ b/libmultipath/uevent.c
> @@ -39,6 +39,7 @@
> #include <linux/netlink.h>
> #include <pthread.h>
> #include <sys/mman.h>
> +#include <sys/time.h>
> #include <libudev.h>
> #include <errno.h>
>
> @@ -490,11 +491,37 @@ struct uevent *uevent_from_udev_device(struct
> udev_device *dev)
> return uev;
> }
>
> +bool uevent_burst(struct timeval *start_time, int events)
> +{
> + struct timeval diff_time, end_time;
> + unsigned long speed;
> + unsigned long eclipse_ms;
> +
> + gettimeofday(&end_time, NULL);
> + timersub(&end_time, start_time, &diff_time);
> +
> + eclipse_ms = diff_time.tv_sec * 1000 + diff_time.tv_usec /
> 1000;
> + if (eclipse_ms == 0)
> + return true;
> + /* max wait 60s */
> + if (eclipse_ms > 60*1000) {
> + condlog(1, "burst continued =%lu ms, stoped",
> eclipse_ms);
> + return false;
> + }
> +
> + speed = (events * 1000) / eclipse_ms;
> + if (speed > 10)
> + return true;
> +
> + return false;
> +}
> +
> int uevent_listen(struct udev *udev)
> {
> int err = 2;
> struct udev_monitor *monitor = NULL;
> int fd, socket_flags, events;
> + struct timeval start_time;
> int need_failback = 1;
> int timeout = 30;
> LIST_HEAD(uevlisten_tmp);
> @@ -548,6 +575,7 @@ int uevent_listen(struct udev *udev)
> }
>
> events = 0;
> + gettimeofday(&start_time, NULL);
> while (1) {
> struct uevent *uev;
> struct udev_device *dev;
> @@ -562,7 +590,8 @@ int uevent_listen(struct udev *udev)
> errno = 0;
> fdcount = poll(&ev_poll, 1, poll_timeout);
> if (fdcount && ev_poll.revents & POLLIN) {
> - timeout = 0;
> + timeout = uevent_burst(&start_time, events +
> 1) ? 1:0;
> +
> dev = udev_monitor_receive_device(monitor);
> if (!dev) {
> condlog(0, "failed getting udev
> device");
> @@ -578,7 +607,8 @@ int uevent_listen(struct udev *udev)
> }
> list_add_tail(&uev->node, &uevlisten_tmp);
> events++;
> - continue;
> + if(events < 2048)
> + continue;
> }
> if (fdcount < 0) {
> if (errno == EINTR)
> @@ -600,6 +630,7 @@ int uevent_listen(struct udev *udev)
> pthread_mutex_unlock(uevq_lockp);
> events = 0;
> }
> + gettimeofday(&start_time, NULL);
> timeout = 30;
> }
> need_failback = 0;
--
Dr. Martin Wilck <mwilck@xxxxxxxx>, Tel. +49 (0)911 74053 2107
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
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