• Len Brown's avatar
    x86/smpboot: Remove APIC.wait_for_init_deassert and atomic init_deasserted · 656bba30
    Len Brown authored
    Both the per-APIC flag ".wait_for_init_deassert",
    and the global atomic_t "init_deasserted"
    are dead code -- remove them.
    
    For all APIC types, "wait_for_master()"
    prevents an AP from proceeding until the BSP has set
    cpu_callout_mask, making "init_deasserted" {unnecessary}:
    
    	BSP: <de-assert INIT>
    	...
    	BSP: {set init_deasserted}
    	AP: wait_for_master()
    		set cpu_initialized_mask
    		wait for cpu_callout_mask
    	BSP: test cpu_initialized_mask
    	BSP: set cpu_callout_mask
    	AP: test cpu_callout_mask
    	AP: {wait for init_deasserted}
    	...
    	AP: <touch APIC>
    
    Deleting the {dead code} above is necessary to enable
    some parallelism in a future patch.
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Arjan van de Ven <arjan@linux.intel.com>
    Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Dave Hansen <dave.hansen@linux.intel.com>
    Cc: Igor Mammedov <imammedo@redhat.com>
    Cc: Jan H. Schönherr <jschoenh@amazon.de>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Zhu Guihua <zhugh.fnst@cn.fujitsu.com>
    Link: http://lkml.kernel.org/r/de4b3a9bab894735e285870b5296da25ee6a8a5a.1439739165.git.len.brown@intel.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    656bba30
smpboot.c 37 KB