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2015-06-30scripts/gdb: add command to check list consistencyThiƩbaud Weksteen2-0/+90
Add a gdb script to verify the consistency of lists. Signed-off-by: ThiƩbaud Weksteen <thiebaud@weksteen.fr> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30memstick: remove deprecated use of pci apiQuentin Lambert2-11/+11
Replace occurences of the pci api by appropriate call to the dma api. A simplified version of the semantic patch that finds this problem is as follows: (http://coccinelle.lip6.fr) @deprecated@ idexpression id; position p; @@ ( pci_dma_supported@p ( id, ...) | pci_alloc_consistent@p ( id, ...) ) @bad1@ idexpression id; position deprecated.p; @@ ...when != &id->dev when != pci_get_drvdata ( id ) when != pci_enable_device ( id ) ( pci_dma_supported@p ( id, ...) | pci_alloc_consistent@p ( id, ...) ) @depends on !bad1@ idexpression id; expression direction; position deprecated.p; @@ ( - pci_dma_supported@p ( id, + dma_supported ( &id->dev, ... + , GFP_ATOMIC ) | - pci_alloc_consistent@p ( id, + dma_alloc_coherent ( &id->dev, ... + , GFP_ATOMIC ) ) Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com> Cc: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30fs/affs/symlink.c: remove unneeded err variableFabian Frederick1-3/+1
err is only assigned to -EIO. Return that value at the end of fail context. Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30fs/affs/amigaffs.c: remove unneeded initializationFabian Frederick1-1/+1
bh is initialized unconditionally in affs_remove_link() Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30fs/affs/inode.c: remove unneeded initializationFabian Frederick1-1/+1
bh is initialized unconditionally in affs_add_entry() Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30fs/adfs: remove unneeded castFiro Yang1-1/+1
kmem_cache_alloc() returns void*. Signed-off-by: Firo Yang <firogm@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30gcov: add support for GCC 5.1Lorenzo Stoakes2-1/+9
Fix kernel gcov support for GCC 5.1. Similar to commit a992bf836f9 ("gcov: add support for GCC 4.9"), this patch takes into account the existence of a new gcov counter (see gcc's gcc/gcov-counter.def.) Firstly, it increments GCOV_COUNTERS (to 10), which makes the data structure struct gcov_info compatible with GCC 5.1. Secondly, a corresponding counter function __gcov_merge_icall_topn (Top N value tracking for indirect calls) is included in base.c with the other gcov counters unused for kernel profiling. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Yuan Pengfei <coolypf@qq.com> Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops pathHATAYAMA Daisuke3-1/+15
Commit f06e5153f4ae2e ("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers") introduced "crash_kexec_post_notifiers" kernel boot option, which toggles wheather panic() calls crash_kexec() before panic_notifiers and dump kmsg or after. The problem is that the commit overlooks panic_on_oops kernel boot option. If it is enabled, crash_kexec() is called directly without going through panic() in oops path. To fix this issue, this patch adds a check to "crash_kexec_post_notifiers" in the condition of kexec_should_crash(). Also, put a comment in kexec_should_crash() to explain not obvious things on this patch. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Acked-by: Baoquan He <bhe@redhat.com> Tested-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30kernel/panic: call the 2nd crash_kexec() only if crash_kexec_post_notifiers is enabledHATAYAMA Daisuke1-1/+2
For compatibility with the behaviour before the commit f06e5153f4ae2e ("kernel/panic.c: add "crash_kexec_post_notifiers" option for kdump after panic_notifers"), the 2nd crash_kexec() should be called only if crash_kexec_post_notifiers is enabled. Note that crash_kexec() returns immediately if kdump crash kernel is not loaded, so in this case, this patch makes no functionality change, but the point is to make it explicit, from the caller panic() side, that the 2nd crash_kexec() does nothing. Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Suggested-by: Ingo Molnar <mingo@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30x86/kexec: prepend elfcorehdr instead of appending it to the crash-kernel command-line.KarimAllah Ahmed1-5/+6
Any parameter passed after '--' in the kernel command-line will not be parsed by the kernel at all, instead it will be passed directly to init process. Currently the kernel appends elfcorehdr=<paddr> to the cmdline passed from kexec load, and if this command-line is used to pass parameters to init process this means that 'elfcorehdr' will not be parsed as a kernel parameter at all which will be a problem for vmcore subsystem since it will know nothing about the location of the ELF structure! Prepending 'elfcorehdr' instead of appending it fixes this problem since it ensures that it always comes before '--' and so it's always parsed as a kernel command-line parameter. Even with this patch things can still go wrong if 'CONFIG_CMDLINE' was also used to embedd a command-line to the crash dump kernel and this command-line contains '--' since the current behavior of the kernel is to actually append the boot loader command-line to the embedded command-line. Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Haren Myneni <hbabu@us.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30fs: document seq_open()'s usage of file->private_dataYann Droneaud1-0/+2
seq_open() stores its struct seq_file in file->private_data, thus it must not be modified by user of seq_file. Link: http://lkml.kernel.org/r/cover.1433193673.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30fs: allocate structure unconditionally in seq_open()Yann Droneaud1-8/+9
Since patch described below, from v2.6.15-rc1, seq_open() could use a struct seq_file already allocated by the caller if the pointer to the structure is stored in file->private_data before calling the function. Commit 1abe77b0fc4b485927f1f798ae81a752677e1d05 Author: Al Viro <viro@zeniv.linux.org.uk> Date: Mon Nov 7 17:15:34 2005 -0500 [PATCH] allow callers of seq_open do allocation themselves Allow caller of seq_open() to kmalloc() seq_file + whatever else they want and set ->private_data to it. seq_open() will then abstain from doing allocation itself. As there's no more use for such feature, as it could be easily replaced by calls to seq_open_private() (see commit 39699037a5c9 ("[FS] seq_file: Introduce the seq_open_private()")) and seq_release_private() (see v2.6.0-test3), support for this uncommon feature can be removed from seq_open(). Link: http://lkml.kernel.org/r/cover.1433193673.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30fs: use seq_open_private() for proc_mountsYann Droneaud3-24/+19
A patchset to remove support for passing pre-allocated struct seq_file to seq_open(). Such feature is undocumented and prone to error. In particular, if seq_release() is used in release handler, it will kfree() a pointer which was not allocated by seq_open(). So this patchset drops support for pre-allocated struct seq_file: it's only of use in proc_namespace.c and can be easily replaced by using seq_open_private()/seq_release_private(). Additionally, it documents the use of file->private_data to hold pointer to struct seq_file by seq_open(). This patch (of 3): Since patch described below, from v2.6.15-rc1, seq_open() could use a struct seq_file already allocated by the caller if the pointer to the structure is stored in file->private_data before calling the function. Commit 1abe77b0fc4b485927f1f798ae81a752677e1d05 Author: Al Viro <viro@zeniv.linux.org.uk> Date: Mon Nov 7 17:15:34 2005 -0500 [PATCH] allow callers of seq_open do allocation themselves Allow caller of seq_open() to kmalloc() seq_file + whatever else they want and set ->private_data to it. seq_open() will then abstain from doing allocation itself. Such behavior is only used by mounts_open_common(). In order to drop support for such uncommon feature, proc_mounts is converted to use seq_open_private(), which take care of allocating the proc_mounts structure, making it available through ->private in struct seq_file. Conversely, proc_mounts is converted to use seq_release_private(), in order to release the private structure allocated by seq_open_private(). Then, ->private is used directly instead of proc_mounts() macro to access to the proc_mounts structure. Link: http://lkml.kernel.org/r/cover.1433193673.git.ydroneaud@opteya.com Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: finish initialisation of struct pages before basic setupMel Gorman5-37/+49
Waiman Long reported that 24TB machines hit OOM during basic setup when struct page initialisation was deferred. One approach is to initialise memory on demand but it interferes with page allocator paths. This patch creates dedicated threads to initialise memory before basic setup. It then blocks on a rw_semaphore until completion as a wait_queue and counter is overkill. This may be slower to boot but it's simplier overall and also gets rid of a section mangling which existed so kswapd could do the initialisation. [akpm@linux-foundation.org: include rwsem.h, use DECLARE_RWSEM, fix comment, remove unneeded cast] Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Waiman Long <waiman.long@hp.com Cc: Nathan Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Scott Norton <scott.norton@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: remove mminit_verify_page_linksMel Gorman3-17/+0
mminit_verify_page_links() is an extremely paranoid check that was introduced when memory initialisation was being heavily reworked. Profiles indicated that up to 10% of parallel memory initialisation was spent on checking this for every page. The cost could be reduced but in practice this check only found problems very early during the initialisation rewrite and has found nothing since. This patch removes an expensive unnecessary check. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: reduce number of times pageblocks are set during struct page initMel Gorman1-22/+24
During parallel sturct page initialisation, ranges are checked for every PFN unnecessarily which increases boot times. This patch alters when the ranges are checked. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: free pages in large chunks where possibleMel Gorman1-6/+49
Parallel struct page frees pages one at a time. Try free pages as single large pages where possible. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30x86: mm: enable deferred struct page initialisation on x86-64Mel Gorman1-0/+1
Subject says it all. Other architectures may enable on a case-by-case basis after auditing early_pfn_to_nid and testing. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: minimise number of pfn->page lookups during initialisationMel Gorman1-5/+24
Deferred struct page initialisation is using pfn_to_page() on every PFN unnecessarily. This patch minimises the number of lookups and scheduler checks. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: initialise remaining struct pages in parallel with kswapdMel Gorman4-6/+130
Only a subset of struct pages are initialised at the moment. When this patch is applied kswapd initialise the remaining struct pages in parallel. This should boot faster by spreading the work to multiple CPUs and initialising data that is local to the CPU. The user-visible effect on large machines is that free memory will appear to rapidly increase early in the lifetime of the system until kswapd reports that all memory is initialised in the kernel log. Once initialised there should be no other user-visibile effects. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: initialise a subset of struct pages if CONFIG_DEFERRED_STRUCT_PAGE_INIT is setMel Gorman5-4/+124
This patch initalises all low memory struct pages and 2G of the highest zone on each node during memory initialisation if CONFIG_DEFERRED_STRUCT_PAGE_INIT is set. That config option cannot be set but will be available in a later patch. Parallel initialisation of struct page depends on some features from memory hotplug and it is necessary to alter alter section annotations. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: inline some helper functionsMel Gorman2-46/+52
early_pfn_in_nid() and meminit_pfn_in_nid() are small functions that are unnecessarily visible outside memory initialisation. As well as unnecessary visibility, it's unnecessary function call overhead when initialising pages. This patch moves the helpers inline. [akpm@linux-foundation.org: fix build] [mhocko@suse.cz: fix build] Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: make __early_pfn_to_nid SMP-safe and introduce meminit_pfn_in_nidMel Gorman4-30/+51
__early_pfn_to_nid() use static variables to cache recent lookups as memblock lookups are very expensive but it assumes that memory initialisation is single-threaded. Parallel initialisation of struct pages will break that assumption so this patch makes __early_pfn_to_nid() SMP-safe by requiring the caller to cache recent search information. early_pfn_to_nid() keeps the same interface but is only safe to use early in boot due to the use of a global static variable. meminit_pfn_in_nid() is an SMP-safe version that callers must maintain their own state for. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: page_alloc: pass PFN to __free_pages_bootmemMel Gorman5-11/+14
__free_pages_bootmem prepares a page for release to the buddy allocator and assumes that the struct page is initialised. Parallel initialisation of struct pages defers initialisation and __free_pages_bootmem can be called for struct pages that cannot yet map struct page to PFN. This patch passes PFN to __free_pages_bootmem with no other functional change. Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Nate Zimmer <nzimmer@sgi.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: only set page reserved in the memblock regionNathan Zimmer3-1/+21
Currently each page struct is set as reserved upon initialization. This patch leaves the reserved bit clear and only sets the reserved bit when it is known the memory was allocated by the bootmem allocator. This makes it easier to distinguish between uninitialised struct pages and reserved struct pages in later patches. Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30mm: meminit: move page initialization into a separate functionRobin Holt1-33/+46
Currently, memmap_init_zone() has all the smarts for initializing a single page. A subset of this is required for parallel page initialisation and so this patch breaks up the monolithic function in preparation. Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-30memblock: introduce a for_each_reserved_mem_region iteratorRobin Holt2-0/+50
Struct page initialisation had been identified as one of the reasons why large machines take a long time to boot. Patches were posted a long time ago to defer initialisation until they were first used. This was rejected on the grounds it should not be necessary to hurt the fast paths. This series reuses much of the work from that time but defers the initialisation of memory to kswapd so that one thread per node initialises memory local to that node. After applying the series and setting the appropriate Kconfig variable I see this in the boot log on a 64G machine [ 7.383764] kswapd 0 initialised deferred memory in 188ms [ 7.404253] kswapd 1 initialised deferred memory in 208ms [ 7.411044] kswapd 3 initialised deferred memory in 216ms [ 7.411551] kswapd 2 initialised deferred memory in 216ms On a 1TB machine, I see [ 8.406511] kswapd 3 initialised deferred memory in 1116ms [ 8.428518] kswapd 1 initialised deferred memory in 1140ms [ 8.435977] kswapd 0 initialised deferred memory in 1148ms [ 8.437416] kswapd 2 initialised deferred memory in 1148ms Once booted the machine appears to work as normal. Boot times were measured from the time shutdown was called until ssh was available again. In the 64G case, the boot time savings are negligible. On the 1TB machine, the savings were 16 seconds. Nate Zimmer said: : On an older 8 TB box with lots and lots of cpus the boot time, as : measure from grub to login prompt, the boot time improved from 1484 : seconds to exactly 1000 seconds. Waiman Long said: : I ran a bootup timing test on a 12-TB 16-socket IvyBridge-EX system. From : grub menu to ssh login, the bootup time was 453s before the patch and 265s : after the patch - a saving of 188s (42%). Daniel Blueman said: : On a 7TB, 1728-core NumaConnect system with 108 NUMA nodes, we're seeing : stock 4.0 boot in 7136s. This drops to 2159s, or a 70% reduction with : this patchset. Non-temporal PMD init (https://lkml.org/lkml/2015/4/23/350) : drops this to 1045s. This patch (of 13): As part of initializing struct page's in 2MiB chunks, we noticed that at the end of free_all_bootmem(), there was nothing which had forced the reserved/allocated 4KiB pages to be initialized. This helper function will be used for that expansion. Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Nate Zimmer <nzimmer@sgi.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Tested-by: Nate Zimmer <nzimmer@sgi.com> Tested-by: Waiman Long <waiman.long@hp.com> Tested-by: Daniel J Blueman <daniel@numascale.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Robin Holt <robinmholt@gmail.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Waiman Long <waiman.long@hp.com> Cc: Scott Norton <scott.norton@hp.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-29Fix kmalloc slab creation sequenceChristoph Lameter2-38/+16
This patch restores the slab creation sequence that was broken by commit 4066c33d0308f8 and also reverts the portions that introduced the KMALLOC_LOOP_XXX macros. Those can never really work since the slab creation is much more complex than just going from a minimum to a maximum number. The latest upstream kernel boots cleanly on my machine with a 64 bit x86 configuration under KVM using either SLAB or SLUB. Fixes: 4066c33d0308f8 ("support the slub_debug boot option") Reported-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-27Revert "jbd2: speedup jbd2_journal_dirty_metadata()"Linus Torvalds1-27/+6
This reverts commit 2143c1965a761332ae417b22fd477b636e4f54ec. This commit seems to be the cause of the following jbd2 assertion failure: ------------[ cut here ]------------ kernel BUG at fs/jbd2/transaction.c:1325! invalid opcode: 0000 [#1] SMP Modules linked in: bnep bluetooth fuse ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 nf_conntrack_ipv6 ... CPU: 7 PID: 5509 Comm: gcc Not tainted 4.1.0-10944-g2a298679b411 #1 Hardware name: /DH87RL, BIOS RLH8710H.86A.0327.2014.0924.1645 09/24/2014 task: ffff8803bf866040 ti: ffff880308528000 task.ti: ffff880308528000 RIP: jbd2_journal_dirty_metadata+0x237/0x290 Call Trace: __ext4_handle_dirty_metadata+0x43/0x1f0 ext4_handle_dirty_dirent_node+0xde/0x160 ? jbd2_journal_get_write_access+0x36/0x50 ext4_delete_entry+0x112/0x160 ? __ext4_journal_start_sb+0x52/0xb0 ext4_unlink+0xfa/0x260 vfs_unlink+0xec/0x190 do_unlinkat+0x24a/0x270 SyS_unlink+0x11/0x20 entry_SYSCALL_64_fastpath+0x12/0x6a ---[ end trace ae033ebde8d080b4 ]--- which is not easily reproducible (I've seen it just once, and then Ted was able to reproduce it once). Revert it while Ted and Jan try to figure out what is wrong. Cc: Jan Kara <jack@suse.cz> Acked-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-26power: axp288_charger: fix for API changeStephen Rothwell1-3/+3
Caused by commit 843735b788a4 ("power: axp288_charger: axp288 charger driver") from the battery tree interacting with commit 046050f6e623 ("extcon: Update the prototype of extcon_register_notifier() with enum extcon") from the extcon tree. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-26staging: wilc1000: disable driver due to build warningsGreg Kroah-Hartman1-0/+1
The wilc1000 has just too many build warnings to be able to enable it for the 4.2 release. Given that there have not been any patches submitted to properly fix these obvious errors, I'm going to disable it for now. I will enable it back when the build warning fixes are submitted, or, if that never happens, I will remove it from the tree. Cc: Johnny Kim <johnny.kim@atmel.com> Cc: Rachel Kim <rachel.kim@atmel.com> Cc: Dean Lee <dean.lee@atmel.com> Cc: Chris Park <chris.park@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-06-26arch, x86: pmem api for ensuring durability of persistent memory updatesRoss Zwisler7-13/+257
Based on an original patch by Ross Zwisler [1]. Writes to persistent memory have the potential to be posted to cpu cache, cpu write buffers, and platform write buffers (memory controller) before being committed to persistent media. Provide apis, memcpy_to_pmem(), wmb_pmem(), and memremap_pmem(), to write data to pmem and assert that it is durable in PMEM (a persistent linear address range). A '__pmem' attribute is added so sparse can track proper usage of pointers to pmem. This continues the status quo of pmem being x86 only for 4.2, but reworks to ioremap, and wider implementation of memremap() will enable other archs in 4.3. [1]: https://lists.01.org/pipermail/linux-nvdimm/2015-May/000932.html Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> [djbw: various reworks] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm: Add sysfs numa_node to NVDIMM devicesToshi Kani5-0/+34
Add support of sysfs 'numa_node' to I/O-related NVDIMM devices under /sys/bus/nd/devices, regionN, namespaceN.0, and bttN.x. An example of numa_node values on a 2-socket system with a single NVDIMM range on each socket is shown below. /sys/bus/nd/devices |-- btt0.0/numa_node:0 |-- btt1.0/numa_node:1 |-- btt1.1/numa_node:1 |-- namespace0.0/numa_node:0 |-- namespace1.0/numa_node:1 |-- region0/numa_node:0 |-- region1/numa_node:1 These numa_node files are then linked under the block class of their device names. /sys/class/block/pmem0/device/numa_node:0 /sys/class/block/pmem1s/device/numa_node:1 This enables numactl(8) to accept 'block:' and 'file:' paths of pmem and btt devices as shown in the examples below. numactl --preferred block:pmem0 --show numactl --preferred file:/dev/pmem1s --show Signed-off-by: Toshi Kani <toshi.kani@hp.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm: Set numa_node to NVDIMM devicesToshi Kani6-1/+16
ACPI NFIT table has System Physical Address Range Structure entries that describe a proximity ID of each range when ACPI_NFIT_PROXIMITY_VALID is set in the flags. Change acpi_nfit_register_region() to map a proximity ID to its node ID, and set it to a new numa_node field of nd_region_desc, which is then conveyed to the nd_region device. The device core arranges for btt and namespace devices to inherit their node from their parent region. Signed-off-by: Toshi Kani <toshi.kani@hp.com> [djbw: move set_dev_node() from region.c to bus.c] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26acpi: Add acpi_map_pxm_to_online_node()Toshi Kani2-3/+52
The kernel initializes CPU & memory's NUMA topology from ACPI SRAT table. Some other ACPI tables, such as NFIT and DMAR, also contain proximity IDs for their device's NUMA topology. This information can be used to improve performance of these devices. This patch introduces acpi_map_pxm_to_online_node(), which is similar to acpi_map_pxm_to_node(), but always returns an online node. When the mapped node from a given proximity ID is offline, it looks up the node distance table and returns the nearest online node. ACPI device drivers, which are called after the NUMA initialization has completed in the kernel, can call this interface to obtain their device NUMA topology from ACPI tables. Such drivers do not have to deal with offline nodes. A node may be offline when a device proximity ID is unique, SRAT memory entry does not exist, or NUMA is disabled, ex. "numa=off" on x86. This patch also moves the pxm range check from acpi_get_node() to acpi_map_pxm_to_node(). Signed-off-by: Toshi Kani <toshi.kani@hp.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, nfit: handle unarmed dimms, mark namespaces read-onlyDan Williams10-3/+100
Upon detection of an unarmed dimm in a region, arrange for descendant BTT, PMEM, or BLK instances to be read-only. A dimm is primarily marked "unarmed" via flags passed by platform firmware (NFIT). The flags in the NFIT memory device sub-structure indicate the state of the data on the nvdimm relative to its energy source or last "flush to persistence". For the most part there is nothing the driver can do but advertise the state of these flags in sysfs and emit a message if firmware indicates that the contents of the device may be corrupted. However, for the case of ACPI_NFIT_MEM_ARMED, the driver can arrange for the block devices incorporating that nvdimm to be marked read-only. This is a safe default as the data is still available and new writes are held off until the administrator either forces read-write mode, or the energy source becomes armed. A 'read_only' attribute is added to REGION devices to allow for overriding the default read-only policy of all descendant block devices. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26pmem: flag pmem block devices as non-rotationalDan Williams1-0/+1
...since they are effectively SSDs as far as userspace is concerned. Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm: enable iostatDan Williams5-2/+59
This is disabled by default as the overhead is prohibitive, but if the user takes the action to turn it on we'll oblige. Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26pmem: make_request cleanupsDan Williams1-21/+5
Various cleanups: 1/ Kill the BUG_ON since we've already told the block layer we don't support DISCARD on all these drivers. 2/ Kill the 'rw' variable, no need to cache it. 3/ Kill the local 'sector' variable. bio_for_each_segment() is already advancing the iterator's sector number by the bio_vec length. 4/ Kill the check for accessing past the end of device generic_make_request_checks() already does that. Suggested-by: Christoph Hellwig <hch@lst.de> [hch: kill access past end of the device check] Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, pmem: fix up max_hw_sectorsDan Williams1-1/+1
There is no hardware limit to enforce on the size of the i/o that can be passed to an nvdimm block device, so set it to UINT_MAX. Reviewed-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, blk: add support for blk integrityVishal Verma5-23/+159
Support multiple block sizes (sector + metadata) for nd_blk in the same way as done for the BTT. Add the idea of an 'internal' lbasize, which is properly aligned and padded, and store metadata in this space. Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, btt: add support for blk integrityVishal Verma5-18/+154
Support multiple block sizes (sector + metadata) using the blk integrity framework. This registers a new integrity template that defines the protection information tuple size based on the configured metadata size, and simply acts as a passthrough for protection information generated by another layer. The metadata is written to the storage as-is, and read back with each sector. Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26fs/block_dev.c: skip rw_page if bdev has integrityVishal Verma1-2/+2
If a block device has bio integrity enabled, rw_page will bypass the integrity payload, which is undesirable. Skip rw_page if this is the case. Currently brd and zram provide rw_page, and the proposed 'nd' drivers will too. Cc: Jens Axboe <axboe@fb.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Suggested-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm: Non-Volatile DevicesDan Williams3-13/+858
Maintainer information and documentation for drivers/nvdimm Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jens Axboe <axboe@fb.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Neil Brown <neilb@suse.de> Cc: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26tools/testing/nvdimm: libnvdimm unit test infrastructureDan Williams9-4/+1377
'libnvdimm' is the first driver sub-system in the kernel to implement mocking for unit test coverage. The nfit_test module gets built as an external module and arranges for external module replacements of nfit, libnvdimm, nd_pmem, and nd_blk. These replacements use the linker --wrap option to redirect calls to ioremap() + request_mem_region() to custom defined unit test resources. The end result is a fully functional nvdimm_bus, as far as userspace is concerned, but with the capability to perform otherwise destructive tests on emulated resources. Q: Why not use QEMU for this emulation? QEMU is not suitable for unit testing. QEMU's role is to faithfully emulate the platform. A unit test's role is to unfaithfully implement the platform with the goal of triggering bugs in the corners of the sub-system implementation. As bugs are discovered in platforms, or the sub-system itself, the unit tests are extended to backstop a fix with a reproducer unit test. Another problem with QEMU is that it would require coordination of 3 software projects instead of 2 (kernel + libndctl [1]) to maintain and execute the tests. The chances for bit rot and the difficulty of getting the tests running goes up non-linearly the more components involved. Q: Why submit this to the kernel tree instead of external modules in libndctl? Simple, to alleviate the same risk that out-of-tree external modules face. Updates to drivers/nvdimm/ can be immediately evaluated to see if they have any impact on tools/testing/nvdimm/. Q: What are the negative implications of merging this? It is a unique maintenance burden because the purpose of mocking an interface to enable a unit test is to purposefully short circuit the semantics of a routine to enable testing. For example __wrap_ioremap_cache() fakes the pmem driver into "ioremap()'ing" a test resource buffer allocated by dma_alloc_coherent(). The future maintenance burden hits when someone changes the semantics of ioremap_cache() and wonders what the implications are for the unit test. [1]: https://github.com/pmem/ndctl Cc: <linux-acpi@vger.kernel.org> Cc: Lv Zheng <lv.zheng@intel.com> Cc: Robert Moore <robert.moore@intel.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memoryRoss Zwisler12-34/+941
The libnvdimm implementation handles allocating dimm address space (DPA) between PMEM and BLK mode interfaces. After DPA has been allocated from a BLK-region to a BLK-namespace the nd_blk driver attaches to handle I/O as a struct bio based block device. Unlike PMEM, BLK is required to handle platform specific details like mmio register formats and memory controller interleave. For this reason the libnvdimm generic nd_blk driver calls back into the bus provider to carry out the I/O. This initial implementation handles the BLK interface defined by the ACPI 6 NFIT [1] and the NVDIMM DSM Interface Example [2] composed from DCR (dimm control region), BDW (block data window), IDT (interleave descriptor) NFIT structures and the hardware register format. [1]: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf [2]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jens Axboe <axboe@fb.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26nd_btt: atomic sector updatesVishal Verma13-25/+1950
BTT stands for Block Translation Table, and is a way to provide power fail sector atomicity semantics for block devices that have the ability to perform byte granularity IO. It relies on the capability of libnvdimm namespace devices to do byte aligned IO. The BTT works as a stacked blocked device, and reserves a chunk of space from the backing device for its accounting metadata. It is a bio-based driver because all IO is done synchronously, and there is no queuing or asynchronous completions at either the device or the driver level. The BTT uses 'lanes' to index into various 'on-disk' data structures, and lanes also act as a synchronization mechanism in case there are more CPUs than available lanes. We did a comparison between two lane lock strategies - first where we kept an atomic counter around that tracked which was the last lane that was used, and 'our' lane was determined by atomically incrementing that. That way, for the nr_cpus > nr_lanes case, theoretically, no CPU would be blocked waiting for a lane. The other strategy was to use the cpu number we're scheduled on to and hash it to a lane number. Theoretically, this could block an IO that could've otherwise run using a different, free lane. But some fio workloads showed that the direct cpu -> lane hash performed faster than tracking 'last lane' - my reasoning is the cache thrash caused by moving the atomic variable made that approach slower than simply waiting out the in-progress IO. This supports the conclusion that the driver can be a very simple bio-based one that does synchronous IOs instead of queuing. Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jens Axboe <axboe@fb.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Neil Brown <neilb@suse.de> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Greg KH <gregkh@linuxfoundation.org> [jmoyer: fix nmi watchdog timeout in btt_map_init] [jmoyer: move btt initialization to module load path] [jmoyer: fix memory leak in the btt initialization path] [jmoyer: Don't overwrite corrupted arenas] Signed-off-by: Vishal Verma <vishal.l.verma@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26dm cache policy smq: fix "default" version to be 1.4.0Mike Snitzer1-1/+1
Commit bccab6a0 ("dm cache: switch the "default" cache replacement policy from mq to smq") should've incremented the "default" policy's version number to 1.4.0 rather than reverting to version 1.0.0. Reported-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-26dm: bump the ioctl version to 4.32.0Mike Snitzer1-2/+2
This fix enables userspace to detect that the dm-stats changes from the 4.2 merge are in place. Reported-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2015-06-26Revert "block, dm: don't copy bios for request clones"Mike Snitzer6-73/+230
This reverts commit 5f1b670d0bef508a5554d92525f5f6d00d640b38. Justification for revert as reported in this dm-devel post: https://www.redhat.com/archives/dm-devel/2015-June/msg00160.html this change should not be pushed to mainline yet. Firstly, Christoph has a newer version of the patch that fixes silent data corruption problem: https://www.redhat.com/archives/dm-devel/2015-May/msg00229.html And the new version still depends on LLDDs to always complete requests to the end when error happens, while block API doesn't enforce such a requirement. If the assumption is ever broken, the inconsistency between request and bio (e.g. rq->__sector and rq->bio) will cause silent data corruption: https://www.redhat.com/archives/dm-devel/2015-June/msg00022.html Reported-by: Junichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>