x86, mce: cleanup mce_start() (7fb06fc9) · Commits · 戴 / test

arch/x86/kernel/cpu/mcheck/mce.c

+31 −35

Original line number	Diff line number	Diff line
		@@ -691,23 +691,21 @@ static atomic_t global_nwo;
		* in the entry order.
		* TBD double check parallel CPU hotunplug
		*/
		static int mce_start(int no_way_out, int *order)
		static int mce_start(int *no_way_out)
		{
		int nwo;
		int order;
		int cpus = num_online_cpus();
		u64 timeout = (u64)monarch_timeout * NSEC_PER_USEC;

		if (!timeout) {
		*order = -1;
		return no_way_out;
		}
		if (!timeout)
		return -1;

		atomic_add(no_way_out, &global_nwo);
		atomic_add(*no_way_out, &global_nwo);
		/*
		* global_nwo should be updated before mce_callin
		*/
		smp_wmb();
		*order = atomic_add_return(1, &mce_callin);
		order = atomic_add_return(1, &mce_callin);

		/*
		* Wait for everyone.
		@@ -715,8 +713,7 @@ static int mce_start(int no_way_out, int *order)
		while (atomic_read(&mce_callin) != cpus) {
		if (mce_timed_out(&timeout)) {
		atomic_set(&global_nwo, 0);
		*order = -1;
		return no_way_out;
		return -1;
		}
		ndelay(SPINUNIT);
		}
		@@ -725,34 +722,34 @@ static int mce_start(int no_way_out, int *order)
		* mce_callin should be read before global_nwo
		*/
		smp_rmb();
		/*
		* Cache the global no_way_out state.
		*/
		nwo = atomic_read(&global_nwo);

		if (order == 1) {
		/*
		* Monarch starts executing now, the others wait.
		* Monarch: Starts executing now, the others wait.
		*/
		if (*order == 1) {
		atomic_set(&mce_executing, 1);
		return nwo;
		}

		} else {
		/*
		* Now start the scanning loop one by one
		* in the original callin order.
		* This way when there are any shared banks it will
		* be only seen by one CPU before cleared, avoiding duplicates.
		* Subject: Now start the scanning loop one by one in
		* the original callin order.
		* This way when there are any shared banks it will be
		* only seen by one CPU before cleared, avoiding duplicates.
		*/
		while (atomic_read(&mce_executing) < *order) {
		while (atomic_read(&mce_executing) < order) {
		if (mce_timed_out(&timeout)) {
		atomic_set(&global_nwo, 0);
		*order = -1;
		return no_way_out;
		return -1;
		}
		ndelay(SPINUNIT);
		}
		return nwo;
		}

		/*
		* Cache the global no_way_out state.
		*/
		*no_way_out = atomic_read(&global_nwo);

		return order;
		}

		/*
		@@ -871,8 +868,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
		* Establish sequential order between the CPUs entering the machine
		* check handler.
		*/
		int order = -1;

		int order;
		/*
		* If no_way_out gets set, there is no safe way to recover from this
		* MCE. If tolerant is cranked up, we'll try anyway.
		@@ -917,7 +913,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
		* This way we don't report duplicated events on shared banks
		* because the first one to see it will clear it.
		*/
		no_way_out = mce_start(no_way_out, &order);
		order = mce_start(&no_way_out);
		for (i = 0; i < banks; i++) {
		__clear_bit(i, toclear);
		if (!bank[i])

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