04/05/2021 21:12, Morten Brørup: > > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Thomas Monjalon > > Sent: Tuesday, May 4, 2021 6:50 PM > > > > 29/04/2021 04:10, Min Hu (Connor): > > > Currently, the mp uses gettimeofday() API to get the time, and used > > as > > > timeout parameter. > > > > > > But the time which gets from gettimeofday() API isn't monotonically > > > increasing. The process may fail if the system time is changed. > > > > > > This fixes it by using clock_gettime() API with monotonic > > attribution. > > > > > > Fixes: 783b6e54971d ("eal: add synchronous multi-process > > communication") > > > Fixes: f05e26051c15 ("eal: add IPC asynchronous request") > > > Cc: sta...@dpdk.org > > > > > > Signed-off-by: Chengwen Feng <fengcheng...@huawei.com> > > > Signed-off-by: Min Hu (Connor) <humi...@huawei.com> > > > --- > > [...] > > > --- a/lib/eal/common/eal_common_proc.c > > > +++ b/lib/eal/common/eal_common_proc.c > > > - if (gettimeofday(&now, NULL) < 0) { > > > - RTE_LOG(ERR, EAL, "Cannot get current time\n"); > > > - goto no_trigger; > > > - } > > > - ts_now.tv_nsec = now.tv_usec * 1000; > > > - ts_now.tv_sec = now.tv_sec; > > > + clock_gettime(CLOCK_MONOTONIC, &ts_now); > > > > Why not testing the return value? > > Because it is guaranteed not to fail. Ref: > https://linux.die.net/man/3/clock_gettime > https://www.freebsd.org/cgi/man.cgi?query=clock_gettime
I see "return 0 for success, or -1 for failure". Where is it said it cannot fail? > > I think this change would not be appropriate after -rc1. > > If you agree, I will postpone to DPDK 21.08. > > It does fix a serious bug, where IPC timeouts can incorrectly happen. And > this is not a theoretical bug; I have seen errors happen due to using the > wrong clock source in other projects. > > However, I have no clue if these IPC library functions are important or not. > So I have no qualified opinion about postponing the change. I think nobody hit such bug with DPDK IPC.
