> -----Original Message----- > From: Yuanhan Liu [mailto:y...@fridaylinux.org] > Sent: Monday, January 8, 2018 9:04 PM > To: Wang, Xiao W <xiao.w.w...@intel.com> > Cc: Bie, Tiwei <tiwei....@intel.com>; dev@dpdk.org; > step...@networkplumber.org > Subject: Re: [PATCH v6 2/3] net/virtio: add packet injection method > > On Sun, Jan 07, 2018 at 04:05:12AM -0800, Xiao Wang wrote: > > + /* > > + * App management thread and virtio interrupt handler thread > > + * both can change the 'started' flag, this lock is meant to > > + * avoid such a contention. > > + */ > > + rte_spinlock_t state_lock; > > Why not turning the "started" to atomic type, so that you don't need > the lock? > > --yliu
To avoid impacting datapath performance, this patch doesn't change "started" to atomic type. During the interrupt handler routine, there are a series of instructions between lock acquire and release. An atomic value is not suitable for this scenario. BRs, Xiao
