> 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 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.
