> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Thomas Monjalon > Sent: Thursday, August 11, 2016 12:05 AM > To: users at dpdk.org; dev at dpdk.org; Gonzalez Monroy, Sergio; Richardson, > Bruce > Cc: Verkamp, Daniel > Subject: Re: [dpdk-dev] [dpdk-users] rte_zmalloc() returning non-zeroed > memory on FreeBSD > > Hi, > > 2016-08-10 23:30, Verkamp, Daniel: > > It seems that with DPDK 16.07, rte_zmalloc() and related functions no > > longer return zeroed memory reliably on FreeBSD. > > > > I notice that commit b78c9175118f7d61022ddc5c62ce54a1bd73cea5 ("mem: > do > > not zero out memory on zmalloc") removed the explicit memset() that > used > > to ensure the buffer was zeroed; its log message says: > > > > "Zeroing out memory on rte_zmalloc_socket is not required anymore since > > all allocated memory is already zeroed." > > On Linux, the memory is zeroed by the kernel. > Then the zero value is maintained in the rte_malloc pool by rte_free. > > > However, I don't see how this is guaranteed (at least for FreeBSD), and > > it is not true in practice. I've attached a minimized reproducer program - > > running it twice in a row fails reliably for me. > > > > Is there a missing step in FreeBSD, or is it a more general problem for > > other platforms? > > I guess the initial value from the kernel has been verified only on Linux. > We could re-add a memset for FreeBSD.
The problem is that the FreeBSD contigmem driver does not re-zero the huge pages each time they are mmap'd - they are only zeroed when contigmem initially loads. I will push a patch for this shortly.
