From: "Rafael J. Wysocki" <rjw@rjwysocki.net> To: Dan Williams <dan.j.williams@intel.com>, Erik Kaneda <erik.kaneda@intel.com> Cc: rafael.j.wysocki@intel.com, Len Brown <lenb@kernel.org>, Borislav Petkov <bp@alien8.de>, James Morse <james.morse@arm.com>, Myron Stowe <myron.stowe@redhat.com>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-nvdimm@lists.01.org, Bob Moore <robert.moore@intel.com> Subject: [RFT][PATCH 0/3] ACPI: ACPICA / OSL: Avoid unmapping ACPI memory inside of the AML interpreter Date: Wed, 10 Jun 2020 14:17:04 +0200 [thread overview] Message-ID: <318372766.6LKUBsbRXE@kreacher> (raw) In-Reply-To: <158889473309.2292982.18007035454673387731.stgit@dwillia2-desk3.amr.corp.intel.com> Hi All, This series is to address the problem with RCU synchronization occurring, possibly relatively often, inside of acpi_ex_system_memory_space_handler(), when the namespace and interpreter mutexes are held. The basic idea is to avoid the actual unmapping of memory in acpi_ex_system_memory_space_handler() by making it take the advantage of the reference counting of memory mappings utilized by the OSL layer in Linux. The basic assumption in patch [1/3] is that if the special ACPI_OS_MAP_MEMORY_FAST_PATH() macro is present, it can be used to increment the reference counter of a known-existing memory mapping in the OS layer which then is dropped by the subsequent acpi_os_unmap_memory() without unmapping the address range at hand. That can be utilized by acpi_ex_system_memory_space_handler() to prevent the reference counters of all mappings used by it from dropping down to 0 (which also prevents the address ranges associated with them from being unmapped) so that they can be unmapped later (specifically, at the operation region deactivation time). Patch [2/3] defers the unmapping even further, until the namespace and interpreter mutexes are released, to avoid invoking the RCU synchronization under theses mutexes. Finally, patch [3/3] changes the OS layer in Linux to provide the ACPI_OS_MAP_MEMORY_FAST_PATH() macro. Note that if this macro is not defined, the code works the way it used to. The series is available from the git branch at git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git \ acpica-osl for easier testing. Cheers, Rafael _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org
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From: "Rafael J. Wysocki" <rjw@rjwysocki.net> To: Dan Williams <dan.j.williams@intel.com>, Erik Kaneda <erik.kaneda@intel.com> Cc: rafael.j.wysocki@intel.com, Len Brown <lenb@kernel.org>, Borislav Petkov <bp@alien8.de>, Ira Weiny <ira.weiny@intel.com>, James Morse <james.morse@arm.com>, Myron Stowe <myron.stowe@redhat.com>, Andy Shevchenko <andriy.shevchenko@linux.intel.com>, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-nvdimm@lists.01.org, Bob Moore <robert.moore@intel.com> Subject: [RFT][PATCH 0/3] ACPI: ACPICA / OSL: Avoid unmapping ACPI memory inside of the AML interpreter Date: Wed, 10 Jun 2020 14:17:04 +0200 [thread overview] Message-ID: <318372766.6LKUBsbRXE@kreacher> (raw) In-Reply-To: <158889473309.2292982.18007035454673387731.stgit@dwillia2-desk3.amr.corp.intel.com> Hi All, This series is to address the problem with RCU synchronization occurring, possibly relatively often, inside of acpi_ex_system_memory_space_handler(), when the namespace and interpreter mutexes are held. The basic idea is to avoid the actual unmapping of memory in acpi_ex_system_memory_space_handler() by making it take the advantage of the reference counting of memory mappings utilized by the OSL layer in Linux. The basic assumption in patch [1/3] is that if the special ACPI_OS_MAP_MEMORY_FAST_PATH() macro is present, it can be used to increment the reference counter of a known-existing memory mapping in the OS layer which then is dropped by the subsequent acpi_os_unmap_memory() without unmapping the address range at hand. That can be utilized by acpi_ex_system_memory_space_handler() to prevent the reference counters of all mappings used by it from dropping down to 0 (which also prevents the address ranges associated with them from being unmapped) so that they can be unmapped later (specifically, at the operation region deactivation time). Patch [2/3] defers the unmapping even further, until the namespace and interpreter mutexes are released, to avoid invoking the RCU synchronization under theses mutexes. Finally, patch [3/3] changes the OS layer in Linux to provide the ACPI_OS_MAP_MEMORY_FAST_PATH() macro. Note that if this macro is not defined, the code works the way it used to. The series is available from the git branch at git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git \ acpica-osl for easier testing. Cheers, Rafael
next prev parent reply other threads:[~2020-06-10 12:23 UTC|newest] Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-07 23:39 [PATCH v2] ACPI: Drop rcu usage for MMIO mappings Dan Williams 2020-05-07 23:39 ` Dan Williams 2020-05-09 12:30 ` Sasha Levin 2020-05-13 8:52 ` [ACPI] 5a91d41f89: BUG:sleeping_function_called_from_invalid_context_at_kernel/locking/mutex.c kernel test robot 2020-05-13 8:52 ` kernel test robot 2020-05-13 8:52 ` kernel test robot 2020-06-05 13:32 ` [PATCH v2] ACPI: Drop rcu usage for MMIO mappings Rafael J. Wysocki 2020-06-05 13:32 ` Rafael J. Wysocki 2020-06-05 16:18 ` Dan Williams 2020-06-05 16:18 ` Dan Williams 2020-06-05 16:21 ` Rafael J. Wysocki 2020-06-05 16:21 ` Rafael J. Wysocki 2020-06-05 16:39 ` Dan Williams 2020-06-05 16:39 ` Dan Williams 2020-06-05 17:02 ` Rafael J. Wysocki 2020-06-05 17:02 ` Rafael J. Wysocki 2020-06-05 14:06 ` [RFT][PATCH] ACPI: OSL: Use rwlock instead of RCU for memory management Rafael J. Wysocki 2020-06-05 14:06 ` Rafael J. Wysocki 2020-06-05 17:08 ` Dan Williams 2020-06-05 17:08 ` Dan Williams 2020-06-06 6:56 ` Rafael J. Wysocki 2020-06-06 6:56 ` Rafael J. Wysocki 2020-06-08 15:33 ` Rafael J. Wysocki 2020-06-08 15:33 ` Rafael J. Wysocki 2020-06-08 16:29 ` Rafael J. Wysocki 2020-06-08 16:29 ` Rafael J. Wysocki 2020-06-05 19:40 ` Andy Shevchenko 2020-06-05 19:40 ` Andy Shevchenko 2020-06-06 6:48 ` Rafael J. Wysocki 2020-06-06 6:48 ` Rafael J. Wysocki 2020-06-10 12:17 ` Rafael J. Wysocki [this message] 2020-06-10 12:17 ` [RFT][PATCH 0/3] ACPI: ACPICA / OSL: Avoid unmapping ACPI memory inside of the AML interpreter Rafael J. Wysocki 2020-06-10 12:20 ` [RFT][PATCH 1/3] ACPICA: Defer unmapping of memory used in memory opregions Rafael J. Wysocki 2020-06-10 12:20 ` Rafael J. Wysocki 2020-06-10 12:21 ` [RFT][PATCH 2/3] ACPICA: Remove unused memory mappings on interpreter exit Rafael J. Wysocki 2020-06-10 12:21 ` Rafael J. Wysocki 2020-06-12 0:12 ` Kaneda, Erik 2020-06-12 0:12 ` Kaneda, Erik 2020-06-12 12:05 ` Rafael J. Wysocki 2020-06-12 12:05 ` Rafael J. Wysocki 2020-06-13 19:28 ` Rafael J. Wysocki 2020-06-13 19:28 ` Rafael J. Wysocki 2020-06-15 19:06 ` Dan Williams 2020-06-15 19:06 ` Dan Williams 2020-06-10 12:22 ` [RFT][PATCH 3/3] ACPI: OSL: Define ACPI_OS_MAP_MEMORY_FAST_PATH() Rafael J. Wysocki 2020-06-10 12:22 ` Rafael J. Wysocki 2020-06-13 19:19 ` [RFT][PATCH 0/3] ACPI: ACPICA / OSL: Avoid unmapping ACPI memory inside of the AML interpreter Rafael J. Wysocki 2020-06-13 19:19 ` Rafael J. Wysocki 2020-06-22 13:50 ` [RFT][PATCH v2 0/4] " Rafael J. Wysocki 2020-06-22 13:50 ` Rafael J. Wysocki 2020-06-22 13:52 ` [RFT][PATCH v2 1/4] ACPICA: Defer unmapping of opregion memory if supported by OS Rafael J. Wysocki 2020-06-22 13:52 ` Rafael J. Wysocki 2020-06-22 13:53 ` [RFT][PATCH v2 2/4] ACPI: OSL: Add support for deferred unmapping of ACPI memory Rafael J. Wysocki 2020-06-22 13:53 ` Rafael J. Wysocki 2020-06-22 14:56 ` Andy Shevchenko 2020-06-22 14:56 ` Andy Shevchenko 2020-06-22 15:27 ` Rafael J. Wysocki 2020-06-22 15:27 ` Rafael J. Wysocki 2020-06-22 15:46 ` Andy Shevchenko 2020-06-22 15:46 ` Andy Shevchenko 2020-06-22 14:01 ` [RFT][PATCH v2 3/4] ACPICA: Preserve memory opregion mappings if supported by OS Rafael J. Wysocki 2020-06-22 14:01 ` Rafael J. Wysocki 2020-06-26 22:53 ` Kaneda, Erik 2020-06-26 22:53 ` Kaneda, Erik 2020-06-29 13:02 ` Rafael J. Wysocki 2020-06-29 13:02 ` Rafael J. Wysocki 2020-06-22 14:02 ` [RFT][PATCH v2 4/4] ACPI: OSL: Implement acpi_os_map_memory_fast_path() Rafael J. Wysocki 2020-06-22 14:02 ` Rafael J. Wysocki 2020-06-26 17:28 ` [RFT][PATCH v3 0/4] ACPI: ACPICA / OSL: Avoid unmapping ACPI memory inside of the AML interpreter Rafael J. Wysocki 2020-06-26 17:28 ` Rafael J. Wysocki 2020-06-26 17:31 ` [RFT][PATCH v3 1/4] ACPICA: Take deferred unmapping of memory into account Rafael J. Wysocki 2020-06-26 17:31 ` Rafael J. Wysocki 2020-06-26 17:31 ` [RFT][PATCH v3 2/4] ACPI: OSL: Implement deferred unmapping of ACPI memory Rafael J. Wysocki 2020-06-26 17:31 ` Rafael J. Wysocki 2020-06-27 11:32 ` kernel test robot 2020-06-26 17:32 ` [RFT][PATCH v3 3/4] ACPICA: Preserve memory opregion mappings if supported by OS Rafael J. Wysocki 2020-06-26 17:32 ` Rafael J. Wysocki 2020-06-26 17:33 ` [RFT][PATCH v3 4/4] ACPI: OSL: Implement acpi_os_map_memory_fast_path() Rafael J. Wysocki 2020-06-26 17:33 ` Rafael J. Wysocki 2020-06-26 18:41 ` [RFT][PATCH v3 0/4] ACPI: ACPICA / OSL: Avoid unmapping ACPI memory inside of the AML interpreter Dan Williams 2020-06-26 18:41 ` Dan Williams 2020-06-28 17:09 ` Rafael J. Wysocki 2020-06-28 17:09 ` Rafael J. Wysocki 2020-06-29 20:46 ` Dan Williams 2020-06-29 20:46 ` Dan Williams 2020-06-30 11:04 ` Rafael J. Wysocki 2020-06-30 11:04 ` Rafael J. Wysocki 2020-06-29 16:31 ` [PATCH v4 0/2] " Rafael J. Wysocki 2020-06-29 16:31 ` Rafael J. Wysocki 2020-06-29 16:33 ` [PATCH v4 1/2] ACPI: OSL: Implement deferred unmapping of ACPI memory Rafael J. Wysocki 2020-06-29 16:33 ` Rafael J. Wysocki 2020-06-29 16:33 ` [PATCH v4 2/2] ACPICA: Preserve memory opregion mappings Rafael J. Wysocki 2020-06-29 16:33 ` Rafael J. Wysocki 2020-06-29 20:57 ` Al Stone 2020-06-29 20:57 ` Al Stone 2020-06-30 11:44 ` Rafael J. Wysocki 2020-06-30 11:44 ` Rafael J. Wysocki 2020-06-30 15:31 ` Al Stone 2020-06-30 15:31 ` Al Stone 2020-06-30 15:52 ` Rafael J. Wysocki 2020-06-30 15:52 ` Rafael J. Wysocki 2020-06-30 19:57 ` Al Stone 2020-06-30 19:57 ` Al Stone 2020-07-16 19:22 ` Verma, Vishal L 2020-07-16 19:22 ` Verma, Vishal L 2020-07-19 19:14 ` Rafael J. Wysocki 2020-07-19 19:14 ` Rafael J. Wysocki
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