Hi Yunjian,
This is not a synchronization problem. The memory is getting
allocated and used in the same thread. Are you using a single socket system?
Thanks,
Honnappa
From: wangyunjian <[email protected]>
Sent: Tuesday, February 8, 2022 2:01 AM
To: Honnappa Nagarahalli <[email protected]>; [email protected];
[email protected]
Cc: Feifei Wang <[email protected]>; Ruifeng Wang <[email protected]>;
Huangshaozhang <[email protected]>; dingxiaoxiong
<[email protected]>; nd <[email protected]>
Subject: RE: [dpdk-dev][dpdk-users] A problem about memory may not be all-zero
allocated by rte_zmalloc_socket()
There is also a condition that the hugepagesz is 1G.
If the hugepagesz is 2M, this problem cannot be repeated.
Thanks,
Yunjian
From: wangyunjian
Sent: Monday, February 7, 2022 10:44 AM
To: 'Honnappa Nagarahalli'
<[email protected]<mailto:[email protected]>>;
[email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]>
Cc: Feifei Wang <[email protected]<mailto:[email protected]>>; Ruifeng
Wang <[email protected]<mailto:[email protected]>>; Huangshaozhang
<[email protected]<mailto:[email protected]>>; dingxiaoxiong
<[email protected]<mailto:[email protected]>>; nd
<[email protected]<mailto:[email protected]>>
Subject: RE: [dpdk-dev][dpdk-users] A problem about memory may not be all-zero
allocated by rte_zmalloc_socket()
Hi, Honnappa
This problem is probability. Test case need to be executed multiple times.
The test steps and code are as follows:
/home/dpdk #./arm64-armv8a-linuxapp-gcc/app/dpdk-testpmd --legacy-mem -c 0xC
-m 8192
app/test-pmd/testpmd.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 55eb293cc0..3c127f9623 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -4251,6 +4251,20 @@ main(int argc, char** argv)
rte_stats_bitrate_reg(bitrate_data);
}
#endif
+
+ printf("start test rte_zmalloc_socket\n");
+ char *a;
+ while((a = rte_zmalloc_socket(NULL, 1024 * 1024, 0, SOCKET_ID_ANY)) !=
NULL) {
+ for (int i = 0; i < 1024 * 1024; i++) {
+ if (a[i] != 0) {
+ printf("a[%d] = %d\n",i,a[i]);
+ }
+ a[i] = 255; // This assignment is important. It can
increase the probability.
+ }
+ }
+ printf("end test rte_zmalloc_socket\n");
+ return EXIT_SUCCESS;
+
#ifdef RTE_LIB_CMDLINE
if (strlen(cmdline_filename) != 0)
cmdline_read_from_file(cmdline_filename);
Thanks,
Yunjian
From: Honnappa Nagarahalli [mailto:[email protected]]
Sent: Monday, January 31, 2022 12:22 PM
To: wangyunjian <[email protected]<mailto:[email protected]>>;
[email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]>
Cc: Feifei Wang <[email protected]<mailto:[email protected]>>; Ruifeng
Wang <[email protected]<mailto:[email protected]>>; Huangshaozhang
<[email protected]<mailto:[email protected]>>; dingxiaoxiong
<[email protected]<mailto:[email protected]>>; Honnappa
Nagarahalli
<[email protected]<mailto:[email protected]>>; nd
<[email protected]<mailto:[email protected]>>
Subject: RE: [dpdk-dev][dpdk-users] A problem about memory may not be all-zero
allocated by rte_zmalloc_socket()
Hi Yunjian,
That's interesting. Is it possible to elaborate the use case or
possibly provide the code snippet?
It is possible that it is a synchronization problem due to relaxed memory model
that Arm architecture uses. There could be a barrier missing in the code.
Thanks,
Honnappa
From: wangyunjian <[email protected]<mailto:[email protected]>>
Sent: Saturday, January 29, 2022 9:21 PM
To: [email protected]<mailto:[email protected]>; [email protected]<mailto:[email protected]>
Cc: Feifei Wang <[email protected]<mailto:[email protected]>>; Ruifeng
Wang <[email protected]<mailto:[email protected]>>; Huangshaozhang
<[email protected]<mailto:[email protected]>>; dingxiaoxiong
<[email protected]<mailto:[email protected]>>
Subject: [dpdk-dev][dpdk-users] A problem about memory may not be all-zero
allocated by rte_zmalloc_socket()
Hi, all
There's a problem that the memory are allocated by rte_zmalloc_socket()
may not be all-zero on the ARM platform.
However, the x86 platform does not have this problem.
Any ideas ?
Thanks,
Yunjian
