Currently on a very large system with 1780 CPUs, hv_acpi_init() takes
around 3 seconds to complete. This is because of sequential synic
initialization for each CPU performed by hv_synic_init().

Schedule these tasks parallelly so that each CPU executes hv_synic_init()
in parallel to take full advantage of multiple CPUs.

This solution saves around 2 seconds of boot time on a 1780 CPU system,
which is around 66% improvement in the existing logic.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Srivatsa S. Bhat (Microsoft) <srivatsa@csail.mit.edu>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/1722488136-6223-1-git-send-email-ssengar@linux.microsoft.comSigned-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <1722488136-6223-1-git-send-email-ssengar@linux.microsoft.com>