Revision a927bd6ba952d13c52b8b385030943032f659a3e authored by Dan Williams on 22 November 2020, 06:17:05 UTC, committed by Linus Torvalds on 22 November 2020, 18:48:22 UTC
The core-mm has a default __weak implementation of phys_to_target_node()
to mirror the weak definition of memory_add_physaddr_to_nid(). That
symbol is exported for modules. However, while the export in
mm/memory_hotplug.c exported the symbol in the configuration cases of:
CONFIG_NUMA_KEEP_MEMINFO=y
CONFIG_MEMORY_HOTPLUG=y
...and:
CONFIG_NUMA_KEEP_MEMINFO=n
CONFIG_MEMORY_HOTPLUG=y
...it failed to export the symbol in the case of:
CONFIG_NUMA_KEEP_MEMINFO=y
CONFIG_MEMORY_HOTPLUG=n
Not only is that broken, but Christoph points out that the kernel should
not be exporting any __weak symbol, which means that
memory_add_physaddr_to_nid() example that phys_to_target_node() copied
is broken too.
Rework the definition of phys_to_target_node() and
memory_add_physaddr_to_nid() to not require weak symbols. Move to the
common arch override design-pattern of an asm header defining a symbol
to replace the default implementation.
The only common header that all memory_add_physaddr_to_nid() producing
architectures implement is asm/sparsemem.h. In fact, powerpc already
defines its memory_add_physaddr_to_nid() helper in sparsemem.h.
Double-down on that observation and define phys_to_target_node() where
necessary in asm/sparsemem.h. An alternate consideration that was
discarded was to put this override in asm/numa.h, but that entangles
with the definition of MAX_NUMNODES relative to the inclusion of
linux/nodemask.h, and requires powerpc to grow a new header.
The dependency on NUMA_KEEP_MEMINFO for DEV_DAX_HMEM_DEVICES is invalid
now that the symbol is properly exported / stubbed in all combinations
of CONFIG_NUMA_KEEP_MEMINFO and CONFIG_MEMORY_HOTPLUG.
[dan.j.williams@intel.com: v4]
Link: https://lkml.kernel.org/r/160461461867.1505359.5301571728749534585.stgit@dwillia2-desk3.amr.corp.intel.com
[dan.j.williams@intel.com: powerpc: fix create_section_mapping compile warning]
Link: https://lkml.kernel.org/r/160558386174.2948926.2740149041249041764.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: a035b6bf863e ("mm/memory_hotplug: introduce default phys_to_target_node() implementation")
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lkml.kernel.org/r/160447639846.1133764.7044090803980177548.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent bc2dc44
debug_locks.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* lib/debug_locks.c
*
* Generic place for common debugging facilities for various locks:
* spinlocks, rwlocks, mutexes and rwsems.
*
* Started by Ingo Molnar:
*
* Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
*/
#include <linux/rwsem.h>
#include <linux/mutex.h>
#include <linux/export.h>
#include <linux/spinlock.h>
#include <linux/debug_locks.h>
/*
* We want to turn all lock-debugging facilities on/off at once,
* via a global flag. The reason is that once a single bug has been
* detected and reported, there might be cascade of followup bugs
* that would just muddy the log. So we report the first one and
* shut up after that.
*/
int debug_locks __read_mostly = 1;
EXPORT_SYMBOL_GPL(debug_locks);
/*
* The locking-testsuite uses <debug_locks_silent> to get a
* 'silent failure': nothing is printed to the console when
* a locking bug is detected.
*/
int debug_locks_silent __read_mostly;
EXPORT_SYMBOL_GPL(debug_locks_silent);
/*
* Generic 'turn off all lock debugging' function:
*/
noinstr int debug_locks_off(void)
{
if (debug_locks && __debug_locks_off()) {
if (!debug_locks_silent) {
console_verbose();
return 1;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(debug_locks_off);
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