diff options
| author | Dave Jiang <dave.jiang@intel.com> | 2018-10-25 22:26:45 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-10-30 11:36:43 +0100 |
| commit | c6ee7a548e2c291398b4f32c1f741c66b9f98e1c (patch) | |
| tree | bcf612b752b9b93ca3f98388bcc60b776004b8b1 /arch | |
| parent | x86/paravirt: Remove unused _paravirt_ident_32 (diff) | |
| download | linux-c6ee7a548e2c291398b4f32c1f741c66b9f98e1c.tar.xz linux-c6ee7a548e2c291398b4f32c1f741c66b9f98e1c.zip | |
x86/numa_emulation: Fix uniform-split numa emulation
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: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Dave 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
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/mm/numa_emulation.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c index b54d52a2d00a..d71d72cf6c66 100644 --- a/arch/x86/mm/numa_emulation.c +++ b/arch/x86/mm/numa_emulation.c @@ -400,9 +400,17 @@ void __init numa_emulation(struct numa_meminfo *numa_meminfo, int numa_dist_cnt) n = simple_strtoul(emu_cmdline, &emu_cmdline, 0); ret = -1; for_each_node_mask(i, physnode_mask) { + /* + * The reason we pass in blk[0] is due to + * numa_remove_memblk_from() called by + * emu_setup_memblk() will delete entry 0 + * and then move everything else up in the pi.blk + * array. Therefore we should always be looking + * at blk[0]. + */ ret = split_nodes_size_interleave_uniform(&ei, &pi, - pi.blk[i].start, pi.blk[i].end, 0, - n, &pi.blk[i], nid); + pi.blk[0].start, pi.blk[0].end, 0, + n, &pi.blk[0], nid); if (ret < 0) break; if (ret < n) { |