<tt>Hi Martin,</tt> <tt>Thank you for your respond, I will modify it and resend it later.</tt> <tt> Regards, Tang</tt> 发件人: Martin Wilck <mwilck@suse.com> 收件人: tang.junhui@zte.com.cn, christophe.varoqui@opensvc.com, hare@suse.de, bmarzins@redhat.com, bart.vanassche@sandisk.com, 抄送: dm-devel@redhat.com, zhang.kai16@zte.com.cn, tang.wenjun3@zte.com.cn 日期: 2016/12/29 04:26 主题: Re: [PATCH 08/12] libmultipath: wait one seconds for more uevents in uevent_listen() in uevents burst situations <hr noshade> <tt>On Tue, 2016-12-27 at 16:03 +0800, tang.junhui@zte.com.cn wrote: > From: tang.junhui <tang.junhui@zte.com.cn> > > 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@zte.com.cn> > --- > 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@suse.com>, Tel. +49 (0)911 74053 2107 SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) </tt>