- 31 Oct, 2018 40 commits
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David Hildenbrand authored
There seem to be some problems as result of 30467e0b ("mm, hotplug: fix concurrent memory hot-add deadlock"), which tried to fix a possible lock inversion reported and discussed in [1] due to the two locks a) device_lock() b) mem_hotplug_lock While add_memory() first takes b), followed by a) during bus_probe_device(), onlining of memory from user space first took a), followed by b), exposing a possible deadlock. In [1], and it was decided to not make use of device_hotplug_lock, but rather to enforce a locking order. The problems I spotted related to this: 1. Memory block device attributes: While .state first calls mem_hotplug_begin() and the calls device_online() - which takes device_lock() - .online does no longer call mem_hotplug_begin(), so effectively calls online_pages() without mem_hotplug_lock. 2. device_online() should be called under device_hotplug_lock, however onlining memory during add_memory() does not take care of that. In addition, I think there is also something wrong about the locking in 3. arch/powerpc/platforms/powernv/memtrace.c calls offline_pages() without locks. This was introduced after 30467e0b. And skimming over the code, I assume it could need some more care in regards to locking (e.g. device_online() called without device_hotplug_lock. This will be addressed in the following patches. Now that we hold the device_hotplug_lock when - adding memory (e.g. via add_memory()/add_memory_resource()) - removing memory (e.g. via remove_memory()) - device_online()/device_offline() We can move mem_hotplug_lock usage back into online_pages()/offline_pages(). Why is mem_hotplug_lock still needed? Essentially to make get_online_mems()/put_online_mems() be very fast (relying on device_hotplug_lock would be very slow), and to serialize against addition of memory that does not create memory block devices (hmm). [1] http://driverdev.linuxdriverproject.org/pipermail/ driverdev-devel/ 2015-February/065324.html This patch is partly based on a patch by Vitaly Kuznetsov. Link: http://lkml.kernel.org/r/20180925091457.28651-4-david@redhat.comSigned-off-by:
David Hildenbrand <david@redhat.com> Reviewed-by:
Pavel Tatashin <pavel.tatashin@microsoft.com> Reviewed-by:
Rashmica Gupta <rashmica.g@gmail.com> Reviewed-by:
Oscar Salvador <osalvador@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Rashmica Gupta <rashmica.g@gmail.com> Cc: Michael Neuling <mikey@neuling.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> Cc: Mathieu Malaterre <malat@debian.org> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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David Hildenbrand authored
add_memory() currently does not take the device_hotplug_lock, however is aleady called under the lock from arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c to synchronize against CPU hot-remove and similar. In general, we should hold the device_hotplug_lock when adding memory to synchronize against online/offline request (e.g. from user space) - which already resulted in lock inversions due to device_lock() and mem_hotplug_lock - see 30467e0b ("mm, hotplug: fix concurrent memory hot-add deadlock"). add_memory()/add_memory_resource() will create memory block devices, so this really feels like the right thing to do. Holding the device_hotplug_lock makes sure that a memory block device can really only be accessed (e.g. via .online/.state) from user space, once the memory has been fully added to the system. The lock is not held yet in drivers/xen/balloon.c arch/powerpc/platforms/powernv/memtrace.c drivers/s390/char/sclp_cmd.c drivers/hv/hv_balloon.c So, let's either use the locked variants or take the lock. Don't export add_memory_resource(), as it once was exported to be used by XEN, which is never built as a module. If somebody requires it, we also have to export a locked variant (as device_hotplug_lock is never exported). Link: http://lkml.kernel.org/r/20180925091457.28651-3-david@redhat.comSigned-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by:
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David Hildenbrand authored
Patch series "mm: online/offline_pages called w.o. mem_hotplug_lock", v3. Reading through the code and studying how mem_hotplug_lock is to be used, I noticed that there are two places where we can end up calling device_online()/device_offline() - online_pages()/offline_pages() without the mem_hotplug_lock. And there are other places where we call device_online()/device_offline() without the device_hotplug_lock. While e.g. echo "online" > /sys/devices/system/memory/memory9/state is fine, e.g. echo 1 > /sys/devices/system/memory/memory9/online Will not take the mem_hotplug_lock. However the device_lock() and device_hotplug_lock. E.g. via memory_probe_store(), we can end up calling add_memory()->online_pages() without the device_hotplug_lock. So we can have concurrent callers in online_pages(). We e.g. touch in online_pages() basically unprotected zone->present_pages then. Looks like there is a longer history to that (see Patch #2 for details), and fixing it to work the way it was intended is not really possible. We would e.g. have to take the mem_hotplug_lock in device/base/core.c, which sounds wrong. Summary: We had a lock inversion on mem_hotplug_lock and device_lock(). More details can be found in patch 3 and patch 6. I propose the general rules (documentation added in patch 6): 1. add_memory/add_memory_resource() must only be called with device_hotplug_lock. 2. remove_memory() must only be called with device_hotplug_lock. This is already documented and holds for all callers. 3. device_online()/device_offline() must only be called with device_hotplug_lock. This is already documented and true for now in core code. Other callers (related to memory hotplug) have to be fixed up. 4. mem_hotplug_lock is taken inside of add_memory/remove_memory/ online_pages/offline_pages. To me, this looks way cleaner than what we have right now (and easier to verify). And looking at the documentation of remove_memory, using lock_device_hotplug also for add_memory() feels natural. This patch (of 6): remove_memory() is exported right now but requires the device_hotplug_lock, which is not exported. So let's provide a variant that takes the lock and only export that one. The lock is already held in arch/powerpc/platforms/pseries/hotplug-memory.c drivers/acpi/acpi_memhotplug.c arch/powerpc/platforms/powernv/memtrace.c Apart from that, there are not other users in the tree. Link: http://lkml.kernel.org/r/20180925091457.28651-2-david@redhat.comSigned-off-by:
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Mike Rapoport authored
After updating all memblock users to explicitly specify SMP_CACHE_BYTES alignment rather than use 0, it is still possible that uncovered users may sneak in. Add a WARN_ON_ONCE for such cases. [sfr@canb.auug.org.au: use dump_stack() instead of WARN_ON_ONCE for the alignment checks] Link: http://lkml.kernel.org/r/20181016131927.6ceba6ab@canb.auug.org.au [akpm@linux-foundation.org: add apologetic comment] Link: http://lkml.kernel.org/r/20181011060850.GA19822@rapoport-lnxSigned-off-by:
Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by:
Stephen Rothwell <sfr@canb.auug.org.au> Reviewed-by:
Michal Hocko <mhocko@suse.com> Signed-off-by:
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Mike Rapoport authored
When a memblock allocation APIs are called with align = 0, the alignment is implicitly set to SMP_CACHE_BYTES. Implicit alignment is done deep in the memblock allocator and it can come as a surprise. Not that such an alignment would be wrong even when used incorrectly but it is better to be explicit for the sake of clarity and the prinicple of the least surprise. Replace all such uses of memblock APIs with the 'align' parameter explicitly set to SMP_CACHE_BYTES and stop implicit alignment assignment in the memblock internal allocation functions. For the case when memblock APIs are used via helper functions, e.g. like iommu_arena_new_node() in Alpha, the helper functions were detected with Coccinelle's help and then manually examined and updated where appropriate. The direct memblock APIs users were updated using the semantic patch below: @@ expression size, min_addr, max_addr, nid; @@ ( | - memblock_alloc_try_nid_raw(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid_raw(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc_try_nid_nopanic(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid_nopanic(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc_try_nid(size, 0, min_addr, max_addr, nid) + memblock_alloc_try_nid(size, SMP_CACHE_BYTES, min_addr, max_addr, nid) | - memblock_alloc(size, 0) + memblock_alloc(size, SMP_CACHE_BYTES) | - memblock_alloc_raw(size, 0) + memblock_alloc_raw(size, SMP_CACHE_BYTES) | - memblock_alloc_from(size, 0, min_addr) + memblock_alloc_from(size, SMP_CACHE_BYTES, min_addr) | - memblock_alloc_nopanic(size, 0) + memblock_alloc_nopanic(size, SMP_CACHE_BYTES) | - memblock_alloc_low(size, 0) + memblock_alloc_low(size, SMP_CACHE_BYTES) | - memblock_alloc_low_nopanic(size, 0) + memblock_alloc_low_nopanic(size, SMP_CACHE_BYTES) | - memblock_alloc_from_nopanic(size, 0, min_addr) + memblock_alloc_from_nopanic(size, SMP_CACHE_BYTES, min_addr) | - memblock_alloc_node(size, 0, nid) + memblock_alloc_node(size, SMP_CACHE_BYTES, nid) ) [mhocko@suse.com: changelog update] [akpm@linux-foundation.org: coding-style fixes] [rppt@linux.ibm.com: fix missed uses of implicit alignment] Link: http://lkml.kernel.org/r/20181016133656.GA10925@rapoport-lnx Link: http://lkml.kernel.org/r/1538687224-17535-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
Link: http://lkml.kernel.org/r/1536927045-23536-31-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include <linux/memblock.h> @@ @@ - #include <linux/bootmem.h> + #include <linux/memblock.h> [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
Drop BOOTMEM_ALLOC_ACCESSIBLE and BOOTMEM_ALLOC_ANYWHERE in favor of identical MEMBLOCK definitions. Link: http://lkml.kernel.org/r/1536927045-23536-29-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
Move a few remaining functions from nobootmem.c to memblock.c and remove nobootmem Link: http://lkml.kernel.org/r/1536927045-23536-28-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The conversion is done using sed -i 's@__free_pages_bootmem@memblock_free_pages@' \ $(git grep -l __free_pages_bootmem) Link: http://lkml.kernel.org/r/1536927045-23536-27-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: -
Mike Rapoport authored
The conversion is done using sed -i 's@free_all_bootmem@memblock_free_all@' \ $(git grep -l free_all_bootmem) Link: http://lkml.kernel.org/r/1536927045-23536-26-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by: -
Mike Rapoport authored
The free_bootmem_late and memblock_free_late do exactly the same thing: they iterate over a range and give pages to the page allocator. Replace calls to free_bootmem_late with calls to memblock_free_late and remove the bootmem variant. Link: http://lkml.kernel.org/r/1536927045-23536-25-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The free_bootmem and free_bootmem_node are merely wrappers for memblock_free. Replace their usage with a call to memblock_free using the following semantic patch: @@ expression e1, e2, e3; @@ ( - free_bootmem(e1, e2) + memblock_free(e1, e2) | - free_bootmem_node(e1, e2, e3) + memblock_free(e2, e3) ) Link: http://lkml.kernel.org/r/1536927045-23536-24-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The bootmem compatibility APIs are not used and can be removed. Link: http://lkml.kernel.org/r/1536927045-23536-23-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The alloc_bootmem(size) is a shortcut for allocation of SMP_CACHE_BYTES aligned memory. When the align parameter of memblock_alloc() is 0, the alignment is implicitly set to SMP_CACHE_BYTES and thus alloc_bootmem(size) and memblock_alloc(size, 0) are equivalent. The conversion is done using the following semantic patch: @@ expression size; @@ - alloc_bootmem(size) + memblock_alloc(size, 0) Link: http://lkml.kernel.org/r/1536927045-23536-22-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The functions are equivalent, just the later does not require nobootmem translation layer. The conversion is done using the following semantic patch: @@ expression size, align, goal; @@ - __alloc_bootmem(size, align, goal) + memblock_alloc_from(size, align, goal) Link: http://lkml.kernel.org/r/1536927045-23536-21-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The alloc_bootmem_pages() function allocates PAGE_SIZE aligned memory. memblock_alloc() with alignment set to PAGE_SIZE does exactly the same thing. The conversion is done using the following semantic patch: @@ expression e; @@ - alloc_bootmem_pages(e) + memblock_alloc(e, PAGE_SIZE) Link: http://lkml.kernel.org/r/1536927045-23536-20-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The alloc_bootmem_low_pages() function allocates PAGE_SIZE aligned regions from low memory. memblock_alloc_low() with alignment set to PAGE_SIZE does exactly the same thing. The conversion is done using the following semantic patch: @@ expression e; @@ - alloc_bootmem_low_pages(e) + memblock_alloc_low(e, PAGE_SIZE) Link: http://lkml.kernel.org/r/1536927045-23536-19-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
Both functions attempt to allocate memory with specified alignment from a particular node. If the allocation from that node fails, they both fall back to allocating from any node in the system. Usage of native memblock API eliminates the nobootmem translation layer. Link: http://lkml.kernel.org/r/1536927045-23536-18-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
Use memblock_alloc_try_nid whenever goal (i.e. minimal address is specified) and memblock_alloc_node otherwise. Link: http://lkml.kernel.org/r/1536927045-23536-17-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The functions are equivalent, just the later does not require nobootmem translation layer. Link: http://lkml.kernel.org/r/1536927045-23536-16-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
With the align parameter memblock_alloc_node() can be used as drop in replacement for alloc_bootmem_pages_node() and __alloc_bootmem_node(), which is done in the following patches. Link: http://lkml.kernel.org/r/1536927045-23536-15-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
When __alloc_bootmem_nopanic() is used with explicit lower limit for the allocation it attempts to allocate memory at or above that limit and falls back to allocation with no limit set. The memblock_alloc_from_nopanic() does exactly the same thing and can be used as a replacement for __alloc_bootmem_nopanic() is such cases. Link: http://lkml.kernel.org/r/1536927045-23536-14-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The alloc_bootmem_low(size) allocates low memory with default alignment and can be replaced by memblock_alloc_low(size, 0) Link: http://lkml.kernel.org/r/1536927045-23536-13-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The alloc_bootmem_pages_nopanic(size) is a shortcut for __alloc_bootmem_nopanic(size, PAGE_SIZE, BOOTMEM_LOW_LIMIT) which allocates PAGE_SIZE aligned memory. Since BOOTMEM_LOW_LIMIT is hardwired to 0 there is no restrictions on where the allocated memory should reside. The memblock_alloc_nopanic(size, PAGE_SIZE) also allocates PAGE_SIZE aligned memory without any restrictions and thus can be used as a replacement for alloc_bootmem_pages_nopanic() Link: http://lkml.kernel.org/r/1536927045-23536-12-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The __alloc_bootmem_node_nopanic() attempts to allocate memory for a specified node. If the allocation fails it then retries to allocate memory from any node. Upon success, the allocated memory is set to 0. The memblock_alloc_try_nid_nopanic() does exactly the same thing and can be used instead. Link: http://lkml.kernel.org/r/1536927045-23536-11-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The functions are equivalent, just the later does not require nobootmem translation layer. Link: http://lkml.kernel.org/r/1536927045-23536-10-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The functions are equivalent, just the later does not require nobootmem translation layer. Link: http://lkml.kernel.org/r/1536927045-23536-9-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
The conversion is done using sed -i 's@memblock_virt_alloc@memblock_alloc@g' \ $(git grep -l memblock_virt_alloc) Link: http://lkml.kernel.org/r/1536927045-23536-8-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
Make it explicit that the caller gets a physical address rather than a virtual one. This will also allow using meblock_alloc prefix for memblock allocations returning virtual address, which is done in the following patches. The conversion is done using the following semantic patch: @@ expression e1, e2, e3; @@ ( - memblock_alloc(e1, e2) + memblock_phys_alloc(e1, e2) | - memblock_alloc_nid(e1, e2, e3) + memblock_phys_alloc_nid(e1, e2, e3) | - memblock_alloc_try_nid(e1, e2, e3) + memblock_phys_alloc_try_nid(e1, e2, e3) ) Link: http://lkml.kernel.org/r/1536927045-23536-7-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
Several bootmem functions and macros are not used. Remove them. Link: http://lkml.kernel.org/r/1536927045-23536-6-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
All architectures have been converted to use MEMBLOCK + NO_BOOTMEM. The bootmem allocator implementation can be removed. Link: http://lkml.kernel.org/r/1536927045-23536-5-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
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Mike Rapoport authored
All architecures use memblock for early memory management. There is no need for the CONFIG_HAVE_MEMBLOCK configuration option. [rppt@linux.vnet.ibm.com: of/fdt: fixup #ifdefs] Link: http://lkml.kernel.org/r/20180919103457.GA20545@rapoport-lnx [rppt@linux.vnet.ibm.com: csky: fixups after bootmem removal] Link: http://lkml.kernel.org/r/20180926112744.GC4628@rapoport-lnx [rppt@linux.vnet.ibm.com: remove stale #else and the code it protects] Link: http://lkml.kernel.org/r/1538067825-24835-1-git-send-email-rppt@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1536927045-23536-4-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
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Mike Rapoport authored
All achitectures select NO_BOOTMEM which essentially becomes 'Y' for any kernel configuration and therefore it can be removed. [alexander.h.duyck@linux.intel.com: remove now defunct NO_BOOTMEM from depends list for deferred init] Link: http://lkml.kernel.org/r/20180925201814.3576.15105.stgit@localhost.localdomain Link: http://lkml.kernel.org/r/1536927045-23536-3-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
Alexander Duyck <alexander.h.duyck@linux.intel.com> Acked-by:
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Alexander Pateenok authored
The macro is not used: $ grep -r PER_CPU_DEF_ATTRIBUTES include/linux/percpu-defs.h: __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES __weak \ include/linux/percpu-defs.h: __PCPU_ATTRS(sec) PER_CPU_DEF_ATTRIBUTES \ include/asm-generic/percpu.h:#ifndef PER_CPU_DEF_ATTRIBUTES include/asm-generic/percpu.h:#define PER_CPU_DEF_ATTRIBUTES It was added with b01e8dc3 ("alpha: fix percpu build breakage") and removed in 2009 with b01e8dc3..6088464c. Link: http://lkml.kernel.org/r/20180821164904.qqhcduimjznods66@K55DR.localdomainSigned-off-by:
Alexander Pateenok <pateenoc@gmail.com> Acked-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
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Arnd Bergmann authored
Building any configuration with 'make W=1' produces a warning: kernel/bounds.c:16:6: warning: no previous prototype for 'foo' [-Wmissing-prototypes] When also passing -Werror, this prevents us from building any other files. Nobody ever calls the function, but we can't make it 'static' either since we want the compiler output. Calling it 'main' instead however avoids the warning, because gcc does not insist on having a declaration for main. Link: http://lkml.kernel.org/r/20181005083313.2088252-1-arnd@arndb.deSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Reported-by:
Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> Reviewed-by:
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Gao Xiang authored
Update the LZ4 compression module based on LZ4 v1.8.3 in order for the erofs file system to use the newest LZ4_decompress_safe_partial() which can now decode exactly the nb of bytes requested [1] to take place of the open hacked code in the erofs file system itself. Currently, apart from the erofs file system, no other users use LZ4_decompress_safe_partial, so no worry about the interface. In addition, LZ4 v1.8.x boosts up decompression speed compared to the current code which is based on LZ4 v1.7.3, mainly due to shortcut optimization for the specific common LZ4-sequences [2]. lzbench testdata (tested in kirin710, 8 cores, 4 big cores at 2189Mhz, 2GB DDR RAM at 1622Mhz, with enwik8 testdata [3]): Compressor name Compress. Decompress. Compr. size Ratio Filename memcpy 5004 MB/s 4924 MB/s 100000000 100.00 enwik8 lz4hc 1.7.3 -9 12 MB/s 653 MB/s 42203253 42.20 enwik8 lz4hc 1.8.0 -9 12 MB/s 908 MB/s 42203096 42.20 enwik8 lz4hc 1.8.3 -9 11 MB/s 965 MB/s 42203094 42.20 enwik8 [1] https://github.com/lz4/lz4/issues/566 https://github.com/lz4/lz4/commit/08d347b5b217b011ff7487130b79480d8cfdaeb8 [2] v1.8.1 perf: slightly faster compression and decompression speed https://github.com/lz4/lz4/commit/a31b7058cb97e4393da55e78a77a1c6f0c9ae038 v1.8.2 perf: slightly faster HC compression and decompression speed https://github.com/lz4/lz4/commit/45f8603aae389d34c689d3ff7427b314071ccd2c https://github.com/lz4/lz4/commit/1a191b3f8d26b50a7c1d41590b529ec308d768cd [3] http://mattmahoney.net/dc/textdata.html http://mattmahoney.net/dc/enwik8.zip Link: http://lkml.kernel.org/r/1537181207-21932-1-git-send-email-gaoxiang25@huawei.comSigned-off-by:
Gao Xiang <gaoxiang25@huawei.com> Tested-by:
Guo Xuenan <guoxuenan@huawei.com> Cc: Colin Ian King <colin.king@canonical.com> Cc: Yann Collet <yann.collet.73@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Fang Wei <fangwei1@huawei.com> Cc: Chao Yu <yuchao0@huawei.com> Cc: Miao Xie <miaoxie@huawei.com> Cc: Sven Schmidt <4sschmid@informatik.uni-hamburg.de> Cc: Kyungsik Lee <kyungsik.lee@lge.com> Cc: <weidu.du@huawei.com> Signed-off-by:
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Waiman Long authored
For SysV semaphores, the semmni value is the last part of the 4-element sem number array. To make semmni behave in a similar way to msgmni and shmmni, we can't directly use the _minmax handler. Instead, a special sem specific handler is added to check the last argument to make sure that it is limited to the [0, IPCMNI] range. An error will be returned if this is not the case. Link: http://lkml.kernel.org/r/1536352137-12003-3-git-send-email-longman@redhat.comSigned-off-by:
Waiman Long <longman@redhat.com> Reviewed-by:
Davidlohr Bueso <dave@stgolabs.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kees Cook <keescook@chromium.org> Cc: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by:
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Waiman Long authored
Patch series "ipc: IPCMNI limit check for *mni & increase that limit", v9. The sysctl parameters msgmni, shmmni and semmni have an inherent limit of IPC_MNI (32k). However, users may not be aware of that because they can write a value much higher than that without getting any error or notification. Reading the parameters back will show the newly written values which are not real. The real IPCMNI limit is now enforced to make sure that users won't put in an unrealistic value. The first 2 patches enforce the limits. There are also users out there requesting increase in the IPCMNI value. The last 2 patches attempt to do that by using a boot kernel parameter "ipcmni_extend" to increase the IPCMNI limit from 32k to 8M if the users really want the extended value. This patch (of 4): A user can write arbitrary integer values to msgmni and shmmni sysctl parameters without getting error, but the actual limit is really IPCMNI (32k). This can mislead users as they think they can get a value that is not real. The right limits are now set for msgmni and shmmni so that the users will become aware if they set a value outside of the acceptable range. Link: http://lkml.kernel.org/r/1536352137-12003-2-git-send-email-longman@redhat.comSigned-off-by:
Luis R. Rodriguez <mcgrof@kernel.org> Reviewed-by:
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Borislav Petkov authored
If a call to panic() terminates the string with a \n , the result puts the closing brace ']---' on a newline because panic() itself adds \n too. Now, if one goes and removes the newline chars from all panic() invocations - and the stats right now look like this: ~300 calls with a \n ~500 calls without a \n one is destined to a neverending game of whack-a-mole because the usual thing to do is add a newline at the end of a string a function is supposed to print. Therefore, simply zap any \n at the end of the panic string to avoid touching so many places in the kernel. Link: http://lkml.kernel.org/r/20181009205019.2786-1-bp@alien8.deSigned-off-by:
Borislav Petkov <bp@suse.de> Acked-by:
Kees Cook <keescook@chromium.org> Reviewed-by:
Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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