leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

net/mlx5: Allow async trigger completion execution on single CPU systems

Browse Source 
For a single CPU system, the kernel thread executing mlx5_cmd_flush()
never releases the CPU but calls down_trylock(&cmd→sem) in a busy loop.
On a single processor system, this leads to a deadlock as the kernel
thread which executes mlx5_cmd_invoke() never gets scheduled. Fix this,
by adding the cond_resched() call to the loop, allow the command
completion kernel thread to execute.

Fixes: 8e715cd613 ("net/mlx5: Set command entry semaphore up once got index free")
Signed-off-by: Alexander Schmidt <alexschm@de.ibm.com>
Signed-off-by: Roy Novich <royno@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
This commit is contained in:
Roy Novich 2022-11-02 23:55:38 -07:00 committed by Saeed Mahameed
parent 15f8f16895
commit 2808b37b59
1 changed files with 8 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
drivers/net/ethernet/mellanox/mlx5/core/cmd.c
View File

@ -1770,12 +1770,17 @@ void mlx5_cmd_flush(struct mlx5_core_dev *dev)
struct mlx5_cmd *cmd = &dev->cmd;
int i;
for (i = 0; i < cmd->max_reg_cmds; i++)
while (down_trylock(&cmd->sem))
for (i = 0; i < cmd->max_reg_cmds; i++) {
while (down_trylock(&cmd->sem)) {
mlx5_cmd_trigger_completions(dev);
cond_resched();
}
}
while (down_trylock(&cmd->pages_sem))
while (down_trylock(&cmd->pages_sem)) {
mlx5_cmd_trigger_completions(dev);
cond_resched();
}
/* Unlock cmdif */
up(&cmd->pages_sem);