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    x86/numa_emulation: Fix uniform-split numa emulation · c6ee7a54
    Dave Jiang 提交于
    The numa_emulation() routine in the 'uniform' case walks through all the
    physical 'memblk' instances and divides them into N emulated nodes with
    split_nodes_size_interleave_uniform(). As each physical node is consumed it
    is removed from the physical memblk array in the numa_remove_memblk_from()
    helper.
    
    Since split_nodes_size_interleave_uniform() handles advancing the array as
    the 'memblk' is consumed it is expected that the base of the array is
    always specified as the argument.
    
    Otherwise, on multi-socket (> 2) configurations the uniform-split
    capability can generate an invalid numa configuration leading to boot
    failures with signatures like the following:
    
        rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
        Sending NMI from CPU 0 to CPUs 2:
        NMI backtrace for cpu 2
        CPU: 2 PID: 1332 Comm: pgdatinit0 Not tainted 4.19.0-rc8-next-20181019-baseline #59
        RIP: 0010:__init_single_page.isra.74+0x81/0x90
        [..]
        Call Trace:
         deferred_init_pages+0xaa/0xe3
         deferred_init_memmap+0x18f/0x318
         kthread+0xf8/0x130
         ? deferred_free_pages.isra.105+0xc9/0xc9
         ? kthread_stop+0x110/0x110
         ret_from_fork+0x35/0x40
    
    Fixes: 1f6a2c6d9f121 ("x86/numa_emulation: Introduce uniform split capability")
    Signed-off-by: NDave Jiang <dave.jiang@intel.com>
    Signed-off-by: NDan Williams <dan.j.williams@intel.com>
    Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
    Tested-by: NAlexander Duyck <alexander.h.duyck@linux.intel.com>
    Reviewed-by: NDave Hansen <dave.hansen@linux.intel.com>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: stable@vger.kernel.org
    Link: https://lkml.kernel.org/r/154049911459.2685845.9210186007479774286.stgit@dwillia2-desk3.amr.corp.intel.com
    c6ee7a54
numa_emulation.c 15.1 KB