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* ipc: rename ipc_obtain_objectDavidlohr Bueso2015-06-305-9/+9
| | | | | | | | | | ... to ipc_obtain_object_idr, which is more meaningful and makes the code slightly easier to follow. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc,msg: provide barrier pairings for lockless receiveDavidlohr Bueso2015-06-301-10/+38
| | | | | | | | | | | | | | | | | | | We currently use a full barrier on the sender side to to avoid receiver tasks disappearing on us while still performing on the sender side wakeup. We lack however, the proper CPU-CPU interactions pairing on the receiver side which busy-waits for the message. Similarly, we do not need a full smp_mb, and can relax the semantics for the writer and reader sides of the message. This is safe as we are only ordering loads and stores to r_msg. And in both smp_wmb and smp_rmb, there are no stores after the calls _anyway_. This obviously applies for pipelined_send and expunge_all, for EIRDM when destroying a queue. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc,shm: move BUG_ON check into shm_lockDavidlohr Bueso2015-06-301-5/+5
| | | | | | | | | | | | Upon every shm_lock call, we BUG_ON if an error was returned, indicating racing either in idr or in shm_destroy. Move this logic into the locking. [akpm@linux-foundation.org: simplify code] Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ipc/util.c: use kvfree() in ipc_rcu_free()Pekka Enberg2015-06-301-4/+1
| | | | | | | | Use kvfree() instead of open-coding it. Signed-off-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arc: use for_each_sg()Akinobu Mita2015-06-301-5/+7
| | | | | | | | | | | | | | This replaces the plain loop over the sglist array with for_each_sg() macro which consists of sg_next() function calls. Since arc doesn't select ARCH_HAS_SG_CHAIN, it is not necessary to use for_each_sg() in order to loop over each sg element. But this can help find problems with drivers that do not properly initialize their sg tables when CONFIG_DEBUG_SG is enabled. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* devpts: if initialization failed, don't crash when opening /dev/ptmxJosh Triplett2015-06-301-7/+24
| | | | | | | | | | | | | | | | | | If devpts failed to initialize, it would store an ERR_PTR in the global devpts_mnt. A subsequent open of /dev/ptmx would call devpts_new_index, which would dereference devpts_mnt and crash. Avoid storing invalid values in devpts_mnt; leave it NULL instead. Make both devpts_new_index and devpts_pty_new fail gracefully with ENODEV in that case, which then becomes the return value to the userspace open call on /dev/ptmx. [akpm@linux-foundation.org: remove unneeded static] Signed-off-by: Josh Triplett <josh@joshtriplett.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* scripts/gdb: remove useless global instructionThiébaud Weksteen2015-06-301-2/+0
| | | | | | | Signed-off-by: Thiébaud 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>
* scripts/gdb: add ps commandThiébaud Weksteen2015-06-301-0/+16
| | | | | | | Signed-off-by: Thiébaud 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>
* scripts/gdb: fix PEP8 complianceThiébaud Weksteen2015-06-304-7/+7
| | | | | | | Signed-off-by: Thiébaud 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>
* scripts/gdb: fix typo in exception nameThiébaud Weksteen2015-06-301-1/+1
| | | | | | | Signed-off-by: Thiébaud 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>
* scripts/gdb: enable completion for lx-list-check parameterJan Kiszka2015-06-301-1/+2
| | | | | | | Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thiébaud Weksteen <thiebaud@weksteen.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* scripts/gdb: also allow list_head pointer as lx-list-check paramterJan Kiszka2015-06-301-2/+4
| | | | | | | | | This makes the usage more flexible. Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thiébaud Weksteen <thiebaud@weksteen.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* scripts/gdb: add command to check list consistencyThiébaud Weksteen2015-06-302-0/+90
| | | | | | | | | Add a gdb script to verify the consistency of lists. Signed-off-by: Thiébaud 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>
* memstick: remove deprecated use of pci apiQuentin Lambert2015-06-302-11/+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>
* fs/affs/symlink.c: remove unneeded err variableFabian Frederick2015-06-301-3/+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>
* fs/affs/amigaffs.c: remove unneeded initializationFabian Frederick2015-06-301-1/+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>
* fs/affs/inode.c: remove unneeded initializationFabian Frederick2015-06-301-1/+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>
* fs/adfs: remove unneeded castFiro Yang2015-06-301-1/+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>
* gcov: add support for GCC 5.1Lorenzo Stoakes2015-06-302-1/+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>
* kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops pathHATAYAMA Daisuke2015-06-303-1/+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>
* kernel/panic: call the 2nd crash_kexec() only if crash_kexec_post_notifiers ↵HATAYAMA Daisuke2015-06-301-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | is enabled 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>
* x86/kexec: prepend elfcorehdr instead of appending it to the crash-kernel ↵KarimAllah Ahmed2015-06-301-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | command-line. 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>
* fs: document seq_open()'s usage of file->private_dataYann Droneaud2015-06-301-0/+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>
* fs: allocate structure unconditionally in seq_open()Yann Droneaud2015-06-301-8/+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>
* fs: use seq_open_private() for proc_mountsYann Droneaud2015-06-303-24/+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>
* mm: meminit: finish initialisation of struct pages before basic setupMel Gorman2015-06-305-37/+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>
* mm: meminit: remove mminit_verify_page_linksMel Gorman2015-06-303-17/+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>
* mm: meminit: reduce number of times pageblocks are set during struct page initMel Gorman2015-06-301-22/+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>
* mm: meminit: free pages in large chunks where possibleMel Gorman2015-06-301-6/+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>
* x86: mm: enable deferred struct page initialisation on x86-64Mel Gorman2015-06-301-0/+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>
* mm: meminit: minimise number of pfn->page lookups during initialisationMel Gorman2015-06-301-5/+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>
* mm: meminit: initialise remaining struct pages in parallel with kswapdMel Gorman2015-06-304-6/+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>
* mm: meminit: initialise a subset of struct pages if ↵Mel Gorman2015-06-305-4/+124
| | | | | | | | | | | | | | | | | | | | | | | | | | | | CONFIG_DEFERRED_STRUCT_PAGE_INIT is set 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>
* mm: meminit: inline some helper functionsMel Gorman2015-06-302-46/+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>
* mm: meminit: make __early_pfn_to_nid SMP-safe and introduce meminit_pfn_in_nidMel Gorman2015-06-304-30/+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>
* mm: page_alloc: pass PFN to __free_pages_bootmemMel Gorman2015-06-305-11/+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>
* mm: meminit: only set page reserved in the memblock regionNathan Zimmer2015-06-303-1/+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>
* mm: meminit: move page initialization into a separate functionRobin Holt2015-06-301-33/+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>
* memblock: introduce a for_each_reserved_mem_region iteratorRobin Holt2015-06-302-0/+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>
* Merge tag 'md/4.2' of git://neil.brown.name/mdLinus Torvalds2015-06-295-101/+146
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull md updates from Neil Brown: "A mixed bag - a few bug fixes - some performance improvement that decrease lock contention - some clean-up Nothing major" * tag 'md/4.2' of git://neil.brown.name/md: md: clear Blocked flag on failed devices when array is read-only. md: unlock mddev_lock on an error path. md: clear mddev->private when it has been freed. md: fix a build warning md/raid5: ignore released_stripes check md/raid5: per hash value and exclusive wait_for_stripe md/raid5: split wait_for_stripe and introduce wait_for_quiescent wait: introduce wait_event_exclusive_cmd md: convert to kstrto*() md/raid10: make sync_request_write() call bio_copy_data()
| * md: clear Blocked flag on failed devices when array is read-only.Neil Brown2015-06-251-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Blocked flag indicates that a device has failed but that this fact hasn't been recorded in the metadata yet. Writes to such devices cannot be allowed until the metadata has been updated. On a read-only array, the Blocked flag will never be cleared. This prevents the device being removed from the array. If the metadata is being handled by the kernel (i.e. !mddev->external), then we can be sure that if the array is switch to writable, then a metadata update will happen and will record the failure. So we don't need the flag set. If metadata is externally managed, it is upto the external manager to clear the 'blocked' flag. Reported-by: XiaoNi <xni@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md: unlock mddev_lock on an error path.NeilBrown2015-06-251-1/+3
| | | | | | | | | | | | | | | | This error path retuns while still holding the lock - bad. Fixes: 6791875e2e53 ("md: make reconfig_mutex optional for writes to md sysfs files.") Cc: stable@vger.kernel.org (v4.0+) Signed-off-by: NeilBrown <neilb@suse.com>
| * md: clear mddev->private when it has been freed.NeilBrown2015-06-251-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If ->private is set when ->run is called, it is assumed to be a 'config' prepared as part of 'reshape'. So it is important when we free that config, that we also clear ->private. This is not often a problem as the mddev will normally be discarded shortly after the config us freed. However if an 'assemble' races with a final close, the assemble can use the old mddev which has a stale ->private. This leads to any of various sorts of crashes. So clear ->private after calling ->free(). Reported-by: Nate Clark <nate@neworld.us> Cc: stable@vger.kernel.org (v4.0+) Fixes: afa0f557cb15 ("md: rename ->stop to ->free") Signed-off-by: NeilBrown <neilb@suse.com>
| * md: fix a build warningFiro Yang2015-06-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Warning like this: drivers/md/md.c: In function "update_array_info": drivers/md/md.c:6394:26: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses] !mddev->persistent != info->not_persistent|| Fix it as Neil Brown said: mddev->persistent != !info->not_persistent || Signed-off-by: Firo Yang <firogm@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: ignore released_stripes checkShaohua Li2015-06-171-2/+2
| | | | | | | | | | | | | | | | | | conf->released_stripes list isn't always related to where there are free stripes pending. Active stripes can be in the list too. And even free stripes were active very recently. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: per hash value and exclusive wait_for_stripeYuanhan Liu2015-06-172-9/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I noticed heavy spin lock contention at get_active_stripe() with fsmark multiple thread write workloads. Here is how this hot contention comes from. We have limited stripes, and it's a multiple thread write workload. Hence, those stripes will be taken soon, which puts later processes to sleep for waiting free stripes. When enough stripes(>= 1/4 total stripes) are released, all process are woken, trying to get the lock. But there is one only being able to get this lock for each hash lock, making other processes spinning out there for acquiring the lock. Thus, it's effectiveless to wakeup all processes and let them battle for a lock that permits one to access only each time. Instead, we could make it be a exclusive wake up: wake up one process only. That avoids the heavy spin lock contention naturally. To do the exclusive wake up, we've to split wait_for_stripe into multiple wait queues, to make it per hash value, just like the hash lock. Here are some test results I have got with this patch applied(all test run 3 times): `fsmark.files_per_sec' ===================== next-20150317 this patch ------------------------- ------------------------- metric_value ±stddev metric_value ±stddev change testbox/benchmark/testcase-params ------------------------- ------------------------- -------- ------------------------------ 25.600 ±0.0 92.700 ±2.5 262.1% ivb44/fsmark/1x-64t-4BRD_12G-RAID5-btrfs-4M-30G-fsyncBeforeClose 25.600 ±0.0 77.800 ±0.6 203.9% ivb44/fsmark/1x-64t-9BRD_6G-RAID5-btrfs-4M-30G-fsyncBeforeClose 32.000 ±0.0 93.800 ±1.7 193.1% ivb44/fsmark/1x-64t-4BRD_12G-RAID5-ext4-4M-30G-fsyncBeforeClose 32.000 ±0.0 81.233 ±1.7 153.9% ivb44/fsmark/1x-64t-9BRD_6G-RAID5-ext4-4M-30G-fsyncBeforeClose 48.800 ±14.5 99.667 ±2.0 104.2% ivb44/fsmark/1x-64t-4BRD_12G-RAID5-xfs-4M-30G-fsyncBeforeClose 6.400 ±0.0 12.800 ±0.0 100.0% ivb44/fsmark/1x-64t-3HDD-RAID5-btrfs-4M-40G-fsyncBeforeClose 63.133 ±8.2 82.800 ±0.7 31.2% ivb44/fsmark/1x-64t-9BRD_6G-RAID5-xfs-4M-30G-fsyncBeforeClose 245.067 ±0.7 306.567 ±7.9 25.1% ivb44/fsmark/1x-64t-4BRD_12G-RAID5-f2fs-4M-30G-fsyncBeforeClose 17.533 ±0.3 21.000 ±0.8 19.8% ivb44/fsmark/1x-1t-3HDD-RAID5-xfs-4M-40G-fsyncBeforeClose 188.167 ±1.9 215.033 ±3.1 14.3% ivb44/fsmark/1x-1t-4BRD_12G-RAID5-btrfs-4M-30G-NoSync 254.500 ±1.8 290.733 ±2.4 14.2% ivb44/fsmark/1x-1t-9BRD_6G-RAID5-btrfs-4M-30G-NoSync `time.system_time' ===================== next-20150317 this patch ------------------------- ------------------------- metric_value ±stddev metric_value ±stddev change testbox/benchmark/testcase-params ------------------------- ------------------------- -------- ------------------------------ 7235.603 ±1.2 185.163 ±1.9 -97.4% ivb44/fsmark/1x-64t-4BRD_12G-RAID5-btrfs-4M-30G-fsyncBeforeClose 7666.883 ±2.9 202.750 ±1.0 -97.4% ivb44/fsmark/1x-64t-9BRD_6G-RAID5-btrfs-4M-30G-fsyncBeforeClose 14567.893 ±0.7 421.230 ±0.4 -97.1% ivb44/fsmark/1x-64t-3HDD-RAID5-btrfs-4M-40G-fsyncBeforeClose 3697.667 ±14.0 148.190 ±1.7 -96.0% ivb44/fsmark/1x-64t-4BRD_12G-RAID5-xfs-4M-30G-fsyncBeforeClose 5572.867 ±3.8 310.717 ±1.4 -94.4% ivb44/fsmark/1x-64t-9BRD_6G-RAID5-ext4-4M-30G-fsyncBeforeClose 5565.050 ±0.5 313.277 ±1.5 -94.4% ivb44/fsmark/1x-64t-4BRD_12G-RAID5-ext4-4M-30G-fsyncBeforeClose 2420.707 ±17.1 171.043 ±2.7 -92.9% ivb44/fsmark/1x-64t-9BRD_6G-RAID5-xfs-4M-30G-fsyncBeforeClose 3743.300 ±4.6 379.827 ±3.5 -89.9% ivb44/fsmark/1x-64t-3HDD-RAID5-ext4-4M-40G-fsyncBeforeClose 3308.687 ±6.3 363.050 ±2.0 -89.0% ivb44/fsmark/1x-64t-3HDD-RAID5-xfs-4M-40G-fsyncBeforeClose Where, 1x: where 'x' means iterations or loop, corresponding to the 'L' option of fsmark 1t, 64t: where 't' means thread 4M: means the single file size, corresponding to the '-s' option of fsmark 40G, 30G, 120G: means the total test size 4BRD_12G: BRD is the ramdisk, where '4' means 4 ramdisk, and where '12G' means the size of one ramdisk. So, it would be 48G in total. And we made a raid on those ramdisk As you can see, though there are no much performance gain for hard disk workload, the system time is dropped heavily, up to 97%. And as expected, the performance increased a lot, up to 260%, for fast device(ram disk). v2: use bits instead of array to note down wait queue need to wake up. Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid5: split wait_for_stripe and introduce wait_for_quiescentYuanhan Liu2015-06-172-6/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I noticed heavy spin lock contention at get_active_stripe(), introduced at being wake up stage, where a bunch of processes try to re-hold the spin lock again. After giving some thoughts on this issue, I found the lock could be relieved(and even avoided) if we turn the wait_for_stripe to per waitqueue for each lock hash and make the wake up exclusive: wake up one process each time, which avoids the lock contention naturally. Before go hacking with wait_for_stripe, I found it actually has 2 usages: for the array to enter or leave the quiescent state, and also to wait for an available stripe in each of the hash lists. So this patch splits the first usage off into a separate wait_queue, wait_for_quiescent, and the next patch will turn the second usage into one waitqueue for each hash value, and make it exclusive, to relieve the lock contention. v2: wake_up(wait_for_quiescent) when (active_stripes == 0) Commit log refactor suggestion from Neil. Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * wait: introduce wait_event_exclusive_cmdYuanhan Liu2015-06-171-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's just a variant of wait_event_cmd(), with exclusive flag being set. For cases like RAID5, which puts many processes to sleep until 1/4 resources are free, a wake_up wakes up all processes to run, but there is one process being able to get the resource as it's protected by a spin lock. That ends up introducing heavy lock contentions, and hurts performance badly. Here introduce wait_event_exclusive_cmd to relieve the lock contention naturally by letting wake_up just wake up one process. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> v2: its assumed that wait*() and __wait*() have the same arguments - peterz Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md: convert to kstrto*()Alexey Dobriyan2015-06-171-68/+81
| | | | | | | | | | | | | | | | | | Convert away from deprecated simple_strto*() functions. Add "fit into sector_t" checks. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
| * md/raid10: make sync_request_write() call bio_copy_data()Kent Overstreet2015-06-171-14/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Refactor sync_request_write() of md/raid10 to use bio_copy_data() instead of open coding bio_vec iterations. Cc: Christoph Hellwig <hch@infradead.org> Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: NeilBrown <neilb@suse.de> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: add more description in commit message] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <mlin@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de>
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