From: Leonardo Bras <leonardo@linux.ibm.com> To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Leonardo Bras <leonardo@linux.ibm.com>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au>, Arnd Bergmann <arnd@arndb.de>, "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>, Christophe Leroy <christophe.leroy@c-s.fr>, Andrew Morton <akpm@linux-foundation.org>, Dan Williams <dan.j.williams@intel.com>, Nicholas Piggin <npiggin@gmail.com>, Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>, Thomas Gleixner <tglx@linutronix.de>, Richard Fontana <rfontana@redhat.com>, Ganesh Goudar <ganeshgr@linux.ibm.com>, Allison Randal <allison@lohutok.net>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Mike Rapoport <rppt@linux.ibm.com>, YueHaibing <yuehaibing@huawei.com>, Ira Weiny <ira.weiny@intel.com>, Jason Gunthorpe <jgg@ziepe.ca>, John Hubbard <jhubbard@nvidia.com>, Keith Busch <keith.busch@intel.com> Subject: [PATCH v2 02/11] asm-generic/pgtable: Adds dummy functions to monitor lockless pgtable walks Date: Fri, 20 Sep 2019 16:50:38 -0300 [thread overview] Message-ID: <20190920195047.7703-3-leonardo@linux.ibm.com> (raw) In-Reply-To: <20190920195047.7703-1-leonardo@linux.ibm.com> There is a need to monitor lockless pagetable walks, in order to avoid doing THP splitting/collapsing during them. Some methods rely on local_irq_{save,restore}, but that can be slow on cases with a lot of cpus are used for the process. In order to speedup these cases, I propose a refcount-based approach, that counts the number of lockless pagetable walks happening on the process. Given that there are lockless pagetable walks on generic code, it's necessary to create dummy functions for archs that won't use the approach. Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com> --- include/asm-generic/pgtable.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 75d9d68a6de7..6eb4fabb5595 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1172,6 +1172,15 @@ static inline bool arch_has_pfn_modify_check(void) #endif #endif +#ifndef __HAVE_ARCH_LOCKLESS_PGTBL_WALK_COUNTER +static inline void start_lockless_pgtbl_walk(struct mm_struct *mm) { } +static inline void end_lockless_pgtbl_walk(struct mm_struct *mm) { } +static inline int running_lockless_pgtbl_walk(struct mm_struct *mm) +{ + return 0; +} +#endif + /* * On some architectures it depends on the mm if the p4d/pud or pmd * layer of the page table hierarchy is folded or not. -- 2.20.1
WARNING: multiple messages have this Message-ID (diff)
From: Leonardo Bras <leonardo@linux.ibm.com> To: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Cc: Keith Busch <keith.busch@intel.com>, Richard Fontana <rfontana@redhat.com>, Paul Mackerras <paulus@samba.org>, Ira Weiny <ira.weiny@intel.com>, Dan Williams <dan.j.williams@intel.com>, "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>, YueHaibing <yuehaibing@huawei.com>, Mike Rapoport <rppt@linux.ibm.com>, Jason Gunthorpe <jgg@ziepe.ca>, Ganesh Goudar <ganeshgr@linux.ibm.com>, Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>, Leonardo Bras <leonardo@linux.ibm.com>, Arnd Bergmann <arnd@arndb.de>, John Hubbard <jhubbard@nvidia.com>, Nicholas Piggin <npiggin@gmail.com>, Thomas Gleixner <tglx@linutronix.de>, Allison Randal <allison@lohutok.net>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Andrew Morton <akpm@linux-foundation.org> Subject: [PATCH v2 02/11] asm-generic/pgtable: Adds dummy functions to monitor lockless pgtable walks Date: Fri, 20 Sep 2019 16:50:38 -0300 [thread overview] Message-ID: <20190920195047.7703-3-leonardo@linux.ibm.com> (raw) In-Reply-To: <20190920195047.7703-1-leonardo@linux.ibm.com> There is a need to monitor lockless pagetable walks, in order to avoid doing THP splitting/collapsing during them. Some methods rely on local_irq_{save,restore}, but that can be slow on cases with a lot of cpus are used for the process. In order to speedup these cases, I propose a refcount-based approach, that counts the number of lockless pagetable walks happening on the process. Given that there are lockless pagetable walks on generic code, it's necessary to create dummy functions for archs that won't use the approach. Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com> --- include/asm-generic/pgtable.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 75d9d68a6de7..6eb4fabb5595 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1172,6 +1172,15 @@ static inline bool arch_has_pfn_modify_check(void) #endif #endif +#ifndef __HAVE_ARCH_LOCKLESS_PGTBL_WALK_COUNTER +static inline void start_lockless_pgtbl_walk(struct mm_struct *mm) { } +static inline void end_lockless_pgtbl_walk(struct mm_struct *mm) { } +static inline int running_lockless_pgtbl_walk(struct mm_struct *mm) +{ + return 0; +} +#endif + /* * On some architectures it depends on the mm if the p4d/pud or pmd * layer of the page table hierarchy is folded or not. -- 2.20.1
next prev parent reply other threads:[~2019-09-20 19:52 UTC|newest] Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-09-20 19:50 [PATCH v2 00/11] Introduces new count-based method for monitoring lockless pagetable wakls Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-20 19:50 ` [PATCH v2 01/11] powerpc/mm: Adds counting method to monitor lockless pgtable walks Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-23 20:42 ` John Hubbard 2019-09-23 20:42 ` John Hubbard 2019-09-23 20:50 ` Leonardo Bras 2019-09-23 20:50 ` Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras [this message] 2019-09-20 19:50 ` [PATCH v2 02/11] asm-generic/pgtable: Adds dummy functions " Leonardo Bras 2019-09-23 20:39 ` John Hubbard 2019-09-23 20:39 ` John Hubbard 2019-09-23 20:48 ` Leonardo Bras 2019-09-23 20:48 ` Leonardo Bras 2019-09-23 20:53 ` John Hubbard 2019-09-23 20:53 ` John Hubbard 2019-09-20 19:50 ` [PATCH v2 03/11] mm/gup: Applies counting method to monitor gup_pgd_range Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-23 20:27 ` John Hubbard 2019-09-23 20:27 ` John Hubbard 2019-09-23 21:01 ` Leonardo Bras 2019-09-23 21:01 ` Leonardo Bras 2019-09-23 21:09 ` John Hubbard 2019-09-23 21:09 ` John Hubbard 2019-09-20 19:50 ` [PATCH v2 04/11] powerpc/mce_power: Applies counting method to monitor lockless pgtbl walks Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-20 19:50 ` [PATCH v2 05/11] powerpc/perf: " Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-20 19:50 ` [PATCH v2 06/11] powerpc/mm/book3s64/hash: " Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-20 19:50 ` [PATCH v2 07/11] powerpc/kvm/e500: " Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-20 19:50 ` [PATCH v2 08/11] powerpc/kvm/book3s_hv: " Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-23 20:47 ` John Hubbard 2019-09-23 20:47 ` John Hubbard 2019-09-20 19:50 ` [PATCH v2 09/11] powerpc/kvm/book3s_64: " Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-20 19:50 ` [PATCH v2 10/11] powerpc/book3s_64: Enables counting method to monitor lockless pgtbl walk Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-20 19:50 ` [PATCH v2 11/11] powerpc/mm/book3s64/pgtable: Uses counting method to skip serializing Leonardo Bras 2019-09-20 19:50 ` Leonardo Bras 2019-09-20 20:11 ` John Hubbard 2019-09-20 20:28 ` Leonardo Bras 2019-09-20 20:28 ` Leonardo Bras 2019-09-20 21:15 ` John Hubbard 2019-09-21 0:48 ` John Hubbard 2019-09-21 0:48 ` John Hubbard 2019-09-23 17:25 ` Leonardo Bras 2019-09-23 17:25 ` Leonardo Bras 2019-09-23 18:14 ` John Hubbard 2019-09-23 18:14 ` John Hubbard 2019-09-23 19:40 ` Leonardo Bras 2019-09-23 19:40 ` Leonardo Bras 2019-09-23 19:58 ` John Hubbard 2019-09-23 19:58 ` John Hubbard 2019-09-23 20:23 ` Leonardo Bras 2019-09-23 20:23 ` Leonardo Bras 2019-09-23 20:26 ` John Hubbard 2019-09-23 20:26 ` John Hubbard 2019-09-20 19:56 ` [PATCH v2 00/11] Introduces new count-based method for monitoring lockless pagetable wakls Leonardo Bras 2019-09-20 19:56 ` Leonardo Bras 2019-09-20 20:12 ` Leonardo Bras 2019-09-20 20:12 ` Leonardo Bras 2019-09-20 21:24 ` John Hubbard 2019-09-20 21:24 ` John Hubbard 2019-09-23 20:51 ` John Hubbard 2019-09-23 20:51 ` John Hubbard 2019-09-23 20:58 ` Leonardo Bras 2019-09-23 20:58 ` Leonardo Bras
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