Messages in this thread | | | From | Arnd Bergmann <> | Subject | Re: [PATCH v2 6/8] IB/hns: Replace counting semaphore event_sem with wait_event | Date | Tue, 25 Oct 2016 14:28:57 +0200 |
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On Tuesday, October 25, 2016 5:31:57 PM CEST Binoy Jayan wrote: > static int __hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param, > u64 out_param, unsigned long in_modifier, > @@ -198,11 +218,12 @@ static int __hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param, > struct hns_roce_cmdq *cmd = &hr_dev->cmd; > struct device *dev = &hr_dev->pdev->dev; > struct hns_roce_cmd_context *context; > - int ret = 0; > + int orig_free_head, ret = 0; > + > + wait_event(cmd->wq, (orig_free_head = atomic_free_node(cmd, -1)) != -1); > > spin_lock(&cmd->context_lock); > - WARN_ON(cmd->free_head < 0); > - context = &cmd->context[cmd->free_head]; > + context = &cmd->context[orig_free_head]; > context->token += cmd->token_mask + 1; > cmd->free_head = context->next; > spin_unlock(&cmd->context_lock); >
You get the lock in atomic_free_node() and then again right after that. Why not combine the two and only take the lock inside of that function that returns a context?
Arnd
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