From: tang.junhui <[email protected]> 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).
Change-Id: I763d491540e8114a81d12d603281540a81502742 Signed-off-by: tang.junhui <[email protected]> --- 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; -- 2.8.1.windows.1 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
