Resending.
============================================================
commit 89681d3655f27d758537ae01a02d500deee1acd6
Author: Mohsin Shaikh <mohsinsha...@niometrics.com>
Date: Thu Apr 9 12:19:45 2020 +0800
net/mlx5: Use open/read/close for reading ib stat
fgets(3)/fread(3)/fscanf(3) etc. use mmap(2)/munmap(2) which leads to TLB
shootdown interrupts to all dpdk app cores including RX cores. This can
cause packet drops. Use read(2)/write(2) instead.
The details can be found here:
https://bugs.dpdk.org/show_bug.cgi?id=440
Bugzilla ID: 440
diff --git a/drivers/net/mlx5/mlx5_stats.c b/drivers/net/mlx5/mlx5_stats.c
index 205e4fe..91ac933 100644
--- a/drivers/net/mlx5/mlx5_stats.c
+++ b/drivers/net/mlx5/mlx5_stats.c
@@ -8,6 +8,8 @@
#include <linux/ethtool.h>
#include <stdint.h>
#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
#include <rte_ethdev_driver.h>
#include <rte_common.h>
@@ -139,20 +141,22 @@
static inline void
mlx5_read_ib_stat(struct mlx5_priv *priv, const char *ctr_name, uint64_t *stat)
{
- FILE *file;
+ int fd;
if (priv->sh) {
MKSTR(path, "%s/ports/%d/hw_counters/%s",
priv->sh->ibdev_path,
priv->ibv_port,
ctr_name);
- file = fopen(path, "rb");
- if (file) {
- int n = fscanf(file, "%" SCNu64, stat);
-
- fclose(file);
- if (n == 1)
+ fd = open(path, O_RDONLY);
+ if (fd != -1) {
+ char buf[32];
+ ssize_t n = read(fd, buf, sizeof(buf));
+ close(fd);
+ if (n != -1) {
+ sscanf(buf, "%" SCNu64, stat);
return;
+ }
}
}
*stat = 0;
============================================================
Thanks,
Mohsin
> On 9 Apr 2020, at 12:26 PM, Mohsin Shaikh <mohsinsha...@niometrics.com> wrote:
>
> Hi Alexander,
>
> Thank you for your quick response. Please find attached the patch for bug
> 440.
>
> - Mohsin
>
>
>
>> On 9 Apr 2020, at 1:07 AM, bugzi...@dpdk.org wrote:
>>
>> https://bugs.dpdk.org/show_bug.cgi?id=440
>>
>> Alexander Kozyrev (akozy...@mellanox.com) changed:
>>
>> What |Removed |Added
>> ----------------------------------------------------------------------------
>> Ever confirmed|0 |1
>> Status|UNCONFIRMED |CONFIRMED
>> CC| |akozy...@mellanox.com
>>
>> --- Comment #1 from Alexander Kozyrev (akozy...@mellanox.com) ---
>> Hi Mohsin, thank you for the problem description and especially for the
>> patch.
>> Would you mind sending this patch to DPDK mailing list so we can integrate
>> it?
>> The patch looks really good to me. The only small thing I would like to
>> change.
>> Could you please use SCNu64 macro instead of "%lu" in the sscanf function?
>> sscanf(buf, "%" SCNu64, stat);
>>
>> --
>> You are receiving this mail because:
>> You reported the bug.
>
