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* seq_file: introduce seq_setwidth() and seq_pad()Tetsuo Handa2013-11-152-0/+30
| | | | | | | | | | | | | | | | There are several users who want to know bytes written by seq_*() for alignment purpose. Currently they are using %n format for knowing it because seq_*() returns 0 on success. This patch introduces seq_setwidth() and seq_pad() for allowing them to align without using %n format. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Joe Perches <joe@perches.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lockref: use BLOATED_SPINLOCKS to avoid explicit config dependenciesPeter Zijlstra2013-11-153-9/+7
| | | | | | | | | | | | Avoid the fragile Kconfig construct guestimating spinlock_t sizes; use a friendly compile-time test to determine this. [kirill.shutemov@linux.intel.com: drop CONFIG_CMPXCHG_LOCKREF] Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: create a separate slab for page->ptl allocationKirill A. Shutemov2013-11-153-1/+17
| | | | | | | | | | | | | | | If DEBUG_SPINLOCK and DEBUG_LOCK_ALLOC are enabled spinlock_t on x86_64 is 72 bytes. For page->ptl they will be allocated from kmalloc-96 slab, so we loose 24 on each. An average system can easily allocate few tens thousands of page->ptl and overhead is significant. Let's create a separate slab for page->ptl allocation to solve this. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: properly separate the bloated ptl from the regular casePeter Zijlstra2013-11-154-21/+25
| | | | | | | | | | | | Use kernel/bounds.c to convert build-time spinlock_t size check into a preprocessor symbol and apply that to properly separate the page::ptl situation. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: dynamically allocate page->ptl if it cannot be embedded to struct pageKirill A. Shutemov2013-11-156-24/+179
| | | | | | | | | | | | | | | | | | | | | | If split page table lock is in use, we embed the lock into struct page of table's page. We have to disable split lock, if spinlock_t is too big be to be embedded, like when DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC enabled. This patch add support for dynamic allocation of split page table lock if we can't embed it to struct page. page->ptl is unsigned long now and we use it as spinlock_t if sizeof(spinlock_t) <= sizeof(long), otherwise it's pointer to spinlock_t. The spinlock_t allocated in pgtable_page_ctor() for PTE table and in pgtable_pmd_page_ctor() for PMD table. All other helpers converted to support dynamically allocated page->ptl. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xtensa: use buddy allocator for PTE tableKirill A. Shutemov2013-11-153-30/+13
| | | | | | | | | | | | | At the moment xtensa uses slab allocator for PTE table. It doesn't work with enabled split page table lock: slab uses page->slab_cache and page->first_page for its pages. These fields share stroage with page->ptl. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Chris Zankel <chris@zankel.net> Acked-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* iommu/arm-smmu: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+4
| | | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Grant Likely <grant.likely@linaro.org> Cc: Rob Herring <rob.herring@calxeda.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xtensa: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+4
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-2/+6
| | | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* unicore32: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-6/+8
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* um: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-2/+6
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* tile: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+5
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sparc: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-152-6/+10
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sh: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+4
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* score: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-3/+6
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Acked-by: Lennox Wu <lennox.wu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* s390: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-2/+9
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* powerpc: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-153-5/+12
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* parisc: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-2/+6
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mips: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-3/+6
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* metag: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-2/+6
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: James Hogan <james.hogan@imgtec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* m68k: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-153-3/+14
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* m32r: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+4
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ia64: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+4
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hexagon: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-4/+6
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* frv: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-4/+8
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cris: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+4
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mikael Starvik <starvik@axis.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* avr32: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+4
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arm64: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-3/+6
| | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arm: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-5/+7
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Russell King <linux@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arc: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-3/+8
| | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> [for arch/arc bits] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* alpha: handle pgtable_page_ctor() failKirill A. Shutemov2013-11-151-1/+4
| | | | | | | | | Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* openrisc: add missing pgtable_page_ctor/dtor callsKirill A. Shutemov2013-11-151-2/+8
| | | | | | | | | | It will fix NR_PAGETABLE accounting. It's also required if the arch is going ever support split ptl. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jonas Bonn <jonas@southpole.se> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mn10300: add missing pgtable_page_ctor/dtor callsKirill A. Shutemov2013-11-152-2/+8
| | | | | | | | | | | It will fix NR_PAGETABLE accounting. It's also required if the arch is going ever support split ptl. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* microblaze: add missing pgtable_page_ctor/dtor callsKirill A. Shutemov2013-11-151-3/+9
| | | | | | | | | | It will fix NR_PAGETABLE accounting. It's also required if the arch is going ever support split ptl. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Simek <monstr@monstr.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: allow pgtable_page_ctor() to failKirill A. Shutemov2013-11-151-1/+2
| | | | | | | | | | | Change pgtable_page_ctor() return type from void to bool. Returns true, if initialization is successful and false otherwise. Current implementation never fails, but it will change later. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* xtensa: fix potential NULL-pointer dereferenceKirill A. Shutemov2013-11-151-1/+5
| | | | | | | | | | Add missing check for memory allocation fail. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* m32r: fix potential NULL-pointer dereferenceKirill A. Shutemov2013-11-151-0/+2
| | | | | | | | | Add missing check for memory allocation fail. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* cris: fix potential NULL-pointer dereferenceKirill A. Shutemov2013-11-151-0/+2
| | | | | | | | | | Add missing check for memory allocation fail. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mikael Starvik <starvik@axis.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86: add missed pgtable_pmd_page_ctor/dtor calls for preallocated pmdsKirill A. Shutemov2013-11-151-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In split page table lock case, we embed spinlock_t into struct page. For obvious reason, we don't want to increase size of struct page if spinlock_t is too big, like with DEBUG_SPINLOCK or DEBUG_LOCK_ALLOC or on -rt kernel. So we disable split page table lock, if spinlock_t is too big. This patchset allows to allocate the lock dynamically if spinlock_t is big. In this page->ptl is used to store pointer to spinlock instead of spinlock itself. It costs additional cache line for indirect access, but fix page fault scalability for multi-threaded applications. LOCK_STAT depends on DEBUG_SPINLOCK, so on current kernel enabling LOCK_STAT to analyse scalability issues breaks scalability. ;) The patchset mostly fixes this. Results for ./thp_memscale -c 80 -b 512M on 4-socket machine: baseline, no CONFIG_LOCK_STAT: 9.115460703 seconds time elapsed baseline, CONFIG_LOCK_STAT=y: 53.890567123 seconds time elapsed patched, no CONFIG_LOCK_STAT: 8.852250368 seconds time elapsed patched, CONFIG_LOCK_STAT=y: 11.069770759 seconds time elapsed Patch count is scary, but most of them trivial. Overview: Patches 1-4 Few bug fixes. No dependencies to other patches. Probably should applied as soon as possible. Patch 5 Changes signature of pgtable_page_ctor(). We will use it for dynamic lock allocation, so it can fail. Patches 6-8 Add missing constructor/destructor calls on few archs. It's fixes NR_PAGETABLE accounting and prepare to use split ptl. Patches 9-33 Add pgtable_page_ctor() fail handling to all archs. Patches 34 Finally adds support of dynamically-allocated page->pte. Also contains documentation for split page table lock. This patch (of 34): I've missed that we preallocate few pmds on pgd_alloc() if X86_PAE enabled. Let's add missed constructor/destructor calls. I haven't noticed it during testing since prep_new_page() clears page->mapping and therefore page->ptl. It's effectively equal to spin_lock_init(&page->ptl). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Chris Zankel <chris@zankel.net> Cc: Christoph Lameter <cl@linux.com> Cc: David Howells <dhowells@redhat.com> Cc: David S. Miller <davem@davemloft.net> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Grant Likely <grant.likely@linaro.org> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Hirokazu Takata <takata@linux-m32r.org> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: James Hogan <james.hogan@imgtec.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: Jonas Bonn <jonas@southpole.se> Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Mikael Starvik <starvik@axis.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rob Herring <rob.herring@calxeda.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* x86, mm: enable split page table lock for PMD levelKirill A. Shutemov2013-11-152-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enable PMD split page table lock for X86_64 and PAE. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: implement split page table lock for PMD levelKirill A. Shutemov2013-11-154-3/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The basic idea is the same as with PTE level: the lock is embedded into struct page of table's page. We can't use mm->pmd_huge_pte to store pgtables for THP, since we don't take mm->page_table_lock anymore. Let's reuse page->lru of table's page for that. pgtable_pmd_page_ctor() returns true, if initialization is successful and false otherwise. Current implementation never fails, but assumption that constructor can fail will help to port it to -rt where spinlock_t is rather huge and cannot be embedded into struct page -- dynamic allocation is required. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert the rest to new page table lock apiKirill A. Shutemov2013-11-154-59/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only trivial cases left. Let's convert them altogether. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, hugetlb: convert hugetlbfs to use split pmd lockKirill A. Shutemov2013-11-157-54/+105
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Hugetlb supports multiple page sizes. We use split lock only for PMD level, but not for PUD. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: do not access mm->pmd_huge_pte directlyKirill A. Shutemov2013-11-154-18/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently mm->pmd_huge_pte protected by page table lock. It will not work with split lock. We have to have per-pmd pmd_huge_pte for proper access serialization. For now, let's just introduce wrapper to access mm->pmd_huge_pte. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: move ptl taking inside page_check_address_pmd()Kirill A. Shutemov2013-11-153-25/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With split page table lock we can't know which lock we need to take before we find the relevant pmd. Let's move lock taking inside the function. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp: change pmd_trans_huge_lock() to return taken lockKirill A. Shutemov2013-11-154-31/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With split ptlock it's important to know which lock pmd_trans_huge_lock() took. This patch adds one more parameter to the function to return the lock. In most places migration to new api is trivial. Exception is move_huge_pmd(): we need to take two locks if pmd tables are different. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: introduce api for split page table lock for PMD levelKirill A. Shutemov2013-11-151-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Basic api, backed by mm->page_table_lock for now. Actual implementation will be added later. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert mm->nr_ptes to atomic_long_tKirill A. Shutemov2013-11-157-14/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With split page table lock for PMD level we can't hold mm->page_table_lock while updating nr_ptes. Let's convert it to atomic_long_t to avoid races. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: rename USE_SPLIT_PTLOCKS to USE_SPLIT_PTE_PTLOCKSKirill A. Shutemov2013-11-154-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're going to introduce split page table lock for PMD level. Let's rename existing split ptlock for PTE level to avoid confusion. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: avoid increase sizeof(struct page) due to split page table lockKirill A. Shutemov2013-11-151-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alex Thorlton noticed that some massively threaded workloads work poorly, if THP enabled. This patchset fixes this by introducing split page table lock for PMD tables. hugetlbfs is not covered yet. This patchset is based on work by Naoya Horiguchi. : akpm result summary: : : THP off, v3.12-rc2: 18.059261877 seconds time elapsed : THP off, patched: 16.768027318 seconds time elapsed : : THP on, v3.12-rc2: 42.162306788 seconds time elapsed : THP on, patched: 8.397885779 seconds time elapsed : : HUGETLB, v3.12-rc2: 47.574936948 seconds time elapsed : HUGETLB, patched: 19.447481153 seconds time elapsed THP off, v3.12-rc2: ------------------- Performance counter stats for './thp_memscale -c 80 -b 512m' (5 runs): 1037072.835207 task-clock # 57.426 CPUs utilized ( +- 3.59% ) 95,093 context-switches # 0.092 K/sec ( +- 3.93% ) 140 cpu-migrations # 0.000 K/sec ( +- 5.28% ) 10,000,550 page-faults # 0.010 M/sec ( +- 0.00% ) 2,455,210,400,261 cycles # 2.367 GHz ( +- 3.62% ) [83.33%] 2,429,281,882,056 stalled-cycles-frontend # 98.94% frontend cycles idle ( +- 3.67% ) [83.33%] 1,975,960,019,659 stalled-cycles-backend # 80.48% backend cycles idle ( +- 3.88% ) [66.68%] 46,503,296,013 instructions # 0.02 insns per cycle # 52.24 stalled cycles per insn ( +- 3.21% ) [83.34%] 9,278,997,542 branches # 8.947 M/sec ( +- 4.00% ) [83.34%] 89,881,640 branch-misses # 0.97% of all branches ( +- 1.17% ) [83.33%] 18.059261877 seconds time elapsed ( +- 2.65% ) THP on, v3.12-rc2: ------------------ Performance counter stats for './thp_memscale -c 80 -b 512m' (5 runs): 3114745.395974 task-clock # 73.875 CPUs utilized ( +- 1.84% ) 267,356 context-switches # 0.086 K/sec ( +- 1.84% ) 99 cpu-migrations # 0.000 K/sec ( +- 1.40% ) 58,313 page-faults # 0.019 K/sec ( +- 0.28% ) 7,416,635,817,510 cycles # 2.381 GHz ( +- 1.83% ) [83.33%] 7,342,619,196,993 stalled-cycles-frontend # 99.00% frontend cycles idle ( +- 1.88% ) [83.33%] 6,267,671,641,967 stalled-cycles-backend # 84.51% backend cycles idle ( +- 2.03% ) [66.67%] 117,819,935,165 instructions # 0.02 insns per cycle # 62.32 stalled cycles per insn ( +- 4.39% ) [83.34%] 28,899,314,777 branches # 9.278 M/sec ( +- 4.48% ) [83.34%] 71,787,032 branch-misses # 0.25% of all branches ( +- 1.03% ) [83.33%] 42.162306788 seconds time elapsed ( +- 1.73% ) HUGETLB, v3.12-rc2: ------------------- Performance counter stats for './thp_memscale_hugetlbfs -c 80 -b 512M' (5 runs): 2588052.787264 task-clock # 54.400 CPUs utilized ( +- 3.69% ) 246,831 context-switches # 0.095 K/sec ( +- 4.15% ) 138 cpu-migrations # 0.000 K/sec ( +- 5.30% ) 21,027 page-faults # 0.008 K/sec ( +- 0.01% ) 6,166,666,307,263 cycles # 2.383 GHz ( +- 3.68% ) [83.33%] 6,086,008,929,407 stalled-cycles-frontend # 98.69% frontend cycles idle ( +- 3.77% ) [83.33%] 5,087,874,435,481 stalled-cycles-backend # 82.51% backend cycles idle ( +- 4.41% ) [66.67%] 133,782,831,249 instructions # 0.02 insns per cycle # 45.49 stalled cycles per insn ( +- 4.30% ) [83.34%] 34,026,870,541 branches # 13.148 M/sec ( +- 4.24% ) [83.34%] 68,670,942 branch-misses # 0.20% of all branches ( +- 3.26% ) [83.33%] 47.574936948 seconds time elapsed ( +- 2.09% ) THP off, patched: ----------------- Performance counter stats for './thp_memscale -c 80 -b 512m' (5 runs): 943301.957892 task-clock # 56.256 CPUs utilized ( +- 3.01% ) 86,218 context-switches # 0.091 K/sec ( +- 3.17% ) 121 cpu-migrations # 0.000 K/sec ( +- 6.64% ) 10,000,551 page-faults # 0.011 M/sec ( +- 0.00% ) 2,230,462,457,654 cycles # 2.365 GHz ( +- 3.04% ) [83.32%] 2,204,616,385,805 stalled-cycles-frontend # 98.84% frontend cycles idle ( +- 3.09% ) [83.32%] 1,778,640,046,926 stalled-cycles-backend # 79.74% backend cycles idle ( +- 3.47% ) [66.69%] 45,995,472,617 instructions # 0.02 insns per cycle # 47.93 stalled cycles per insn ( +- 2.51% ) [83.34%] 9,179,700,174 branches # 9.731 M/sec ( +- 3.04% ) [83.35%] 89,166,529 branch-misses # 0.97% of all branches ( +- 1.45% ) [83.33%] 16.768027318 seconds time elapsed ( +- 2.47% ) THP on, patched: ---------------- Performance counter stats for './thp_memscale -c 80 -b 512m' (5 runs): 458793.837905 task-clock # 54.632 CPUs utilized ( +- 0.79% ) 41,831 context-switches # 0.091 K/sec ( +- 0.97% ) 98 cpu-migrations # 0.000 K/sec ( +- 1.66% ) 57,829 page-faults # 0.126 K/sec ( +- 0.62% ) 1,077,543,336,716 cycles # 2.349 GHz ( +- 0.81% ) [83.33%] 1,067,403,802,964 stalled-cycles-frontend # 99.06% frontend cycles idle ( +- 0.87% ) [83.33%] 864,764,616,143 stalled-cycles-backend # 80.25% backend cycles idle ( +- 0.73% ) [66.68%] 16,129,177,440 instructions # 0.01 insns per cycle # 66.18 stalled cycles per insn ( +- 7.94% ) [83.35%] 3,618,938,569 branches # 7.888 M/sec ( +- 8.46% ) [83.36%] 33,242,032 branch-misses # 0.92% of all branches ( +- 2.02% ) [83.32%] 8.397885779 seconds time elapsed ( +- 0.18% ) HUGETLB, patched: ----------------- Performance counter stats for './thp_memscale_hugetlbfs -c 80 -b 512M' (5 runs): 395353.076837 task-clock # 20.329 CPUs utilized ( +- 8.16% ) 55,730 context-switches # 0.141 K/sec ( +- 5.31% ) 138 cpu-migrations # 0.000 K/sec ( +- 4.24% ) 21,027 page-faults # 0.053 K/sec ( +- 0.00% ) 930,219,717,244 cycles # 2.353 GHz ( +- 8.21% ) [83.32%] 914,295,694,103 stalled-cycles-frontend # 98.29% frontend cycles idle ( +- 8.35% ) [83.33%] 704,137,950,187 stalled-cycles-backend # 75.70% backend cycles idle ( +- 9.16% ) [66.69%] 30,541,538,385 instructions # 0.03 insns per cycle # 29.94 stalled cycles per insn ( +- 3.98% ) [83.35%] 8,415,376,631 branches # 21.286 M/sec ( +- 3.61% ) [83.36%] 32,645,478 branch-misses # 0.39% of all branches ( +- 3.41% ) [83.32%] 19.447481153 seconds time elapsed ( +- 2.00% ) This patch (of 11): CONFIG_GENERIC_LOCKBREAK increases sizeof(spinlock_t) to 8 bytes. It leads to increase sizeof(struct page) by 4 bytes on 32-bit system if split page table lock is in use, since page->ptl shares space in union with longs and pointers. Let's disable split page table lock on 32-bit systems with GENERIC_LOCKBREAK enabled. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Alex Thorlton <athorlton@sgi.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Dave Jones <davej@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kees Cook <keescook@chromium.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>