- 21 May, 2016 2 commits
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Johannes Weiner authored
Andres observed that his database workload is struggling with the transaction journal creating pressure on frequently read pages. Access patterns like transaction journals frequently write the same pages over and over, but in the majority of cases those pages are never read back. There are no caching benefits to be had for those pages, so activating them and having them put pressure on pages that do benefit from caching is a bad choice. Leave page activations to read accesses and don't promote pages based on writes alone. It could be said that partially written pages do contain cache-worthy data, because even if *userspace* does not access the unwritten part, the kernel still has to read it from the filesystem for correctness. However, a counter argument is that these pages enjoy at least *some* protection over other inactive file pages through the writeback cache, in the sense that dirty pages are written back with a delay and cache reclaim leaves them alone until they have been written back to disk. Should that turn out to be insufficient and we see increased read IO from partial writes under memory pressure, we can always go back and update grab_cache_page_write_begin() to take (pos, len) so that it can tell partial writes from pages that don't need partial reads. But for now, keep it simple. Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Reported-by:
Andres Freund <andres@anarazel.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Rik van Riel authored
This is a follow-up to http://www.spinics.net/lists/linux-mm/msg101739.html where Andres reported his database workingset being pushed out by the minimum size enforcement of the inactive file list - currently 50% of cache - as well as repeatedly written file pages that are never actually read. Two changes fell out of the discussions. The first change observes that pages that are only ever written don't benefit from caching beyond what the writeback cache does for partial page writes, and so we shouldn't promote them to the active file list where they compete with pages whose cached data is actually accessed repeatedly. This change comes in two patches - one for in-cache write accesses and one for refaults triggered by writes, neither of which should promote a cache page. Second, with the refault detection we don't need to set 50% of the cache aside for used-once cache anymore since we can detect frequently used pages even when they are evicted between accesses. We can allow the active list to be bigger and thus protect a bigger workingset that isn't challenged by streamers. Depending on the access patterns, this can increase major faults during workingset transitions for better performance during stable phases. This patch (of 3): When rewriting a page, the data in that page is replaced with new data. This means that evicting something else from the active file list, in order to cache data that will be replaced by something else, is likely to be a waste of memory. It is better to save the active list for frequently read pages, because reads actually use the data that is in the page. This patch ignores partial writes, because it is unclear whether the complexity of identifying those is worth any potential performance gain obtained from better caching pages that see repeated partial writes at large enough intervals to not get caught by the use-twice promotion code used for the inactive file list. Signed-off-by:
Rik van Riel <riel@redhat.com> Signed-off-by:
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- 20 May, 2016 38 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfdLinus Torvalds authored
Pull MFD updates from Lee Jones: "New Drivers: - Add new driver for MAXIM MAX77620/MAX20024 PMIC - Add new driver for Hisilicon HI665X PMIC New Device Support: - Add support for AXP809 in axp20x-rsb - Add support for Power Supply in axp20x New core features: - devm_mfd_* managed resources Fix-ups: - Remove unused code (da9063-irq, wm8400-core, tps6105x, smsc-ece1099, twl4030-power) - Improve clean-up in error path (intel_quark_i2c_gpio) - Explicitly include headers (syscon.h) - Allow building as modules (max77693) - Use IS_ENABLED() instead of rolling your own (dm355evm_msp, wm8400-core) - DT adaptions (axp20x, hi655x, arizona, max77620) - Remove CLK_IS_ROOT flag (intel-lpss, intel_quark) - Move to gpiochip API (asic3, dm355evm_msp, htc-egpio, htc-i2cpld, sm501, tc6393xb, tps65010, ucb1x00, vexpress) - Make use of devm_mfd_* calls (act8945a, as3711, atmel-hlcdc, bcm590xx, hi6421-pmic-core, lp3943, menf21bmc, mt6397, rdc321x, rk808, rn5t618, rt5033, sky81452, stw481x, tps6507x, tps65217, wm8400) Bug Fixes" - Fix ACPI child matching (mfd-core) - Fix start-up ordering issues (mt6397-core, arizona-core) - Fix forgotten register state on resume (intel-lpss) - Fix Clock related issues (twl6040) - Fix scheduling whilst atomic (omap-usb-tll) - Kconfig changes (vexpress)" * tag 'mfd-for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (73 commits) mfd: hi655x: Add MFD driver for hi655x mfd: ab8500-debugfs: Trivial fix of spelling mistake on "between" mfd: vexpress: Add !ARCH_USES_GETTIMEOFFSET dependency mfd: Add device-tree binding doc for PMIC MAX77620/MAX20024 mfd: max77620: Add core driver for MAX77620/MAX20024 mfd: arizona: Add defines for GPSW values that can be used from DT mfd: omap-usb-tll: Fix scheduling while atomic BUG mfd: wm5110: ARIZONA_CLOCK_CONTROL should be volatile mfd: axp20x: Add a cell for the ac power_supply part of the axp20x PMICs mfd: intel_soc_pmic_core: Terminate panel control GPIO lookup table correctly mfd: wl1273-core: Use devm_mfd_add_devices() for mfd_device registration mfd: tps65910: Use devm_mfd_add_devices and devm_regmap_add_irq_chip mfd: sec: Use devm_mfd_add_devices and devm_regmap_add_irq_chip mfd: rc5t583: Use devm_mfd_add_devices and devm_request_threaded_irq mfd: max77686: Use devm_mfd_add_devices and devm_regmap_add_irq_chip mfd: as3722: Use devm_mfd_add_devices and devm_regmap_add_irq_chip mfd: twl4030-power: Remove driver path in file comment MAINTAINERS: Add entry for X-Powers AXP family PMIC drivers mfd: smsc-ece1099: Remove unnecessarily remove callback mfd: Use IS_ENABLED(CONFIG_FOO) instead of checking FOO || FOO_MODULE ... -
git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-hsiLinus Torvalds authored
Pull HSI updates from Sebastian Reichel: - merge omap-ssi and omap-ssi-port modules - fix omap-ssi module reloading - add DVFS support to omap-ssi * tag 'hsi-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-hsi: HSI: omap-ssi: move omap_ssi_port_update_fclk HSI: omap-ssi: include pinctrl header files HSI: omap-ssi: add COMMON_CLK dependency HSI: omap-ssi: add clk change support HSI: omap_ssi: built omap_ssi and omap_ssi_port into one module HSI: omap_ssi: fix removal of port platform device HSI: omap_ssi: make sure probe stays available HSI: omap_ssi: fix module unloading HSI: omap_ssi_port: switch to gpiod API
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git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linuxLinus Torvalds authored
Pull fbdev updates from Tomi Valkeinen: - imxfb: fix lcd power up - small fixes and cleanups * tag 'fbdev-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tomba/linux: fbdev: Use IS_ENABLED() instead of checking for built-in or module efifb: Don't show the mapping VA video: AMBA CLCD: Remove unncessary include in amba-clcd.c fbdev: ssd1307fb: Fix charge pump setting Documentation: fb: fix spelling mistakes fbdev: fbmem: implement error handling in fbmem_init() fbdev: sh_mipi_dsi: remove driver video: fbdev: imxfb: add some error handling video: fbdev: imxfb: fix semantic of .get_power and .set_power video: fbdev: omap2: Remove deprecated regulator_can_change_voltage() usage
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git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6Linus Torvalds authored
Pull crypto fix from Herbert Xu: "Fix a regression that causes sha-mb to crash" * 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: crypto: sha1-mb - make sha1_x8_avx2() conform to C function ABI
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Arnd Bergmann authored
The newly added nps irqchip driver causes build warnings on ARM64. include/soc/nps/common.h: In function 'nps_host_reg_non_cl': include/soc/nps/common.h:148:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] As the driver is only used on ARC, we don't need to see it without COMPILE_TEST elsewhere, and we can avoid the warnings by only building on 32-bit architectures even with CONFIG_COMPILE_TEST. Acked-by:
Marc Zyngier <narc.zyngier@arm.com> Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
Vineet Gupta <vgupta@synopsys.com> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull powerpc updates from Michael Ellerman: "Highlights: - Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V - Live patching support for ppc64le (also merged via livepatching.git) Various cleanups & minor fixes from: - Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie, Lennart Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Michael Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras, Rashmica Gupta, Russell Currey, Suraj Jitindar Singh, Thiago Jung Bauermann, Valentin Rothberg, Vipin K Parashar. General: - Update LMB associativity index during DLPAR add/remove from Nathan Fontenot - Fix branching to OOL handlers in relocatable kernel from Hari Bathini - Add support for userspace Power9 copy/paste from Chris Smart - Always use STRICT_MM_TYPECHECKS from Michael Ellerman - Add mask of possible MMU features from Michael Ellerman PCI: - Enable pass through of NVLink to guests from Alexey Kardashevskiy - Cleanups in preparation for powernv PCI hotplug from Gavin Shan - Don't report error in eeh_pe_reset_and_recover() from Gavin Shan - Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan - Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" from Guilherme G Piccoli - Remove the dependency on EEH struct in DDW mechanism from Guilherme G Piccoli selftests: - Test cp_abort during context switch from Chris Smart - Add several tests for transactional memory support from Rashmica Gupta perf: - Add support for sampling interrupt register state from Anju T - Add support for unwinding perf-stackdump from Chandan Kumar cxl: - Configure the PSL for two CAPI ports on POWER8NVL from Philippe Bergheaud - Allow initialization on timebase sync failures from Frederic Barrat - Increase timeout for detection of AFU mmio hang from Frederic Barrat - Handle num_of_processes larger than can fit in the SPA from Ian Munsie - Ensure PSL interrupt is configured for contexts with no AFU IRQs from Ian Munsie - Add kernel API to allow a context to operate with relocate disabled from Ian Munsie - Check periodically the coherent platform function's state from Christophe Lombard Freescale: - Updates from Scott: "Contains 86xx fixes, minor device tree fixes, an erratum workaround, and a kconfig dependency fix." * tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (192 commits) powerpc/86xx: Fix PCI interrupt map definition powerpc/86xx: Move pci1 definition to the include file powerpc/fsl: Fix build of the dtb embedded kernel images powerpc/fsl: Fix rcpm compatible string powerpc/fsl: Remove FSL_SOC dependency from FSL_LBC powerpc/fsl-pci: Add a workaround for PCI 5 errata powerpc/fsl: Fix SPI compatible on t208xrdb and t1040rdb powerpc/powernv/npu: Add PE to PHB's list powerpc/powernv: Fix insufficient memory allocation powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" powerpc/eeh: Drop unnecessary label in eeh_pe_change_owner() powerpc/eeh: Ignore handlers in eeh_pe_reset_and_recover() powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover() powerpc/eeh: Don't report error in eeh_pe_reset_and_recover() Revert "powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()" powerpc/powernv/npu: Enable NVLink pass through powerpc/powernv/npu: Rework TCE Kill handling powerpc/powernv/npu: Add set/unset window helpers powerpc/powernv/ioda2: Export debug helper pe_level_printk() ... -
git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds authored
Pull ARM updates from Russell King: "Changes included in this pull request: - revert pxa2xx-flash back to using ioremap_cached() and switch memremap() to use arch_memremap_wb() - remove pci=firmware command line argument handling - remove unnecessary arm_dma_set_mask() implementation, the generic implementation will do for ARM - removal of the ARM kallsyms "hack" to work around mode switching veneers and vectors located below PAGE_OFFSET - tidy up build system output a little - add L2 cache power management DT bindings - remove duplicated local_irq_disable() in reboot paths - handle AMBA primecell devices better at registration time with PM domains (needed for Samsung SoCs) - ARM specific preparation to support Keystone II kexec" * 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 8567/1: cache-uniphier: activate ways for secondary CPUs ARM: 8570/2: Documentation: devicetree: Add PL310 PM bindings ARM: 8569/1: pl2x0: Add OF control of cache power management ARM: 8568/1: reboot: remove duplicated local_irq_disable() ARM: 8566/1: drivers: amba: properly handle devices with power domains ARM: provide arm_has_idmap_alias() helper ARM: kexec: remove 512MB restriction on kexec crashdump ARM: provide improved virt_to_idmap() functionality ARM: kexec: fix crashkernel= handling ARM: 8557/1: specify install, zinstall, and uinstall as PHONY targets ARM: 8562/1: suppress "include/generated/mach-types.h is up to date." ARM: 8553/1: kallsyms: remove --page-offset command line option ARM: 8552/1: kallsyms: remove special lower address limit for CONFIG_ARM ARM: 8555/1: kallsyms: ignore ARM mode switching veneers ARM: 8548/1: dma-mapping: remove arm_dma_set_mask() ARM: 8554/1: kernel: pci: remove pci=firmware command line parameter handling ARM: memremap: implement arch_memremap_wb() memremap: add arch specific hook for MEMREMAP_WB mappings mtd: pxa2xx-flash: switch back from memremap to ioremap_cached ARM: reintroduce ioremap_cached() for creating cached I/O mappings -
Linus Torvalds authored
Merge updates from Andrew Morton: - fsnotify fix - poll() timeout fix - a few scripts/ tweaks - debugobjects updates - the (small) ocfs2 queue - Minor fixes to kernel/padata.c - Maybe half of the MM queue * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits) mm, page_alloc: restore the original nodemask if the fast path allocation failed mm, page_alloc: uninline the bad page part of check_new_page() mm, page_alloc: don't duplicate code in free_pcp_prepare mm, page_alloc: defer debugging checks of pages allocated from the PCP mm, page_alloc: defer debugging checks of freed pages until a PCP drain cpuset: use static key better and convert to new API mm, page_alloc: inline pageblock lookup in page free fast paths mm, page_alloc: remove unnecessary variable from free_pcppages_bulk mm, page_alloc: pull out side effects from free_pages_check mm, page_alloc: un-inline the bad part of free_pages_check mm, page_alloc: check multiple page fields with a single branch mm, page_alloc: remove field from alloc_context mm, page_alloc: avoid looking up the first zone in a zonelist twice mm, page_alloc: shortcut watermark checks for order-0 pages mm, page_alloc: reduce cost of fair zone allocation policy retry mm, page_alloc: shorten the page allocator fast path mm, page_alloc: check once if a zone has isolated pageblocks mm, page_alloc: move __GFP_HARDWALL modifications out of the fastpath mm, page_alloc: simplify last cpupid reset mm, page_alloc: remove unnecessary initialisation from __alloc_pages_nodemask() ...
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Mel Gorman authored
The page allocator fast path uses either the requested nodemask or cpuset_current_mems_allowed if cpusets are enabled. If the allocation context allows watermarks to be ignored then it can also ignore memory policies. However, on entering the allocator slowpath the nodemask may still be cpuset_current_mems_allowed and the policies are enforced. This patch resets the nodemask appropriately before entering the slowpath. Link: http://lkml.kernel.org/r/20160504143628.GU2858@techsingularity.netSigned-off-by:
Vlastimil Babka <vbabka@suse.cz> Signed-off-by:
Mel Gorman <mgorman@techsingularity.net> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by:
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Vlastimil Babka authored
Bad pages should be rare so the code handling them doesn't need to be inline for performance reasons. Put it to separate function which returns void. This also assumes that the initial page_expected_state() result will match the result of the thorough check, i.e. the page doesn't become "good" in the meanwhile. This matches the same expectations already in place in free_pages_check(). !DEBUG_VM bloat-o-meter: add/remove: 1/0 grow/shrink: 0/1 up/down: 134/-274 (-140) function old new delta check_new_page_bad - 134 +134 get_page_from_freelist 3468 3194 -274 Signed-off-by:
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Mel Gorman authored
The new free_pcp_prepare() function shares a lot of code with free_pages_prepare(), which makes this a maintenance risk when some future patch modifies only one of them. We should be able to achieve the same effect (skipping free_pages_check() from !DEBUG_VM configs) by adding a parameter to free_pages_prepare() and making it inline, so the checks (and the order != 0 parts) are eliminated from the call from free_pcp_prepare(). !DEBUG_VM: bloat-o-meter reports no difference, as my gcc was already inlining free_pages_prepare() and the elimination seems to work as expected DEBUG_VM bloat-o-meter: add/remove: 0/1 grow/shrink: 2/0 up/down: 1035/-778 (257) function old new delta __free_pages_ok 297 1060 +763 free_hot_cold_page 480 752 +272 free_pages_prepare 778 - -778 Here inlining didn't occur before, and added some code, but it's ok for a debug option. [akpm@linux-foundation.org: fix build] Signed-off-by:
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Mel Gorman authored
Every page allocated checks a number of page fields for validity. This catches corruption bugs of pages that are already freed but it is expensive. This patch weakens the debugging check by checking PCP pages only when the PCP lists are being refilled. All compound pages are checked. This potentially avoids debugging checks entirely if the PCP lists are never emptied and refilled so some corruption issues may be missed. Full checking requires DEBUG_VM. With the two deferred debugging patches applied, the impact to a page allocator microbenchmark is 4.6.0-rc3 4.6.0-rc3 inline-v3r6 deferalloc-v3r7 Min alloc-odr0-1 344.00 ( 0.00%) 317.00 ( 7.85%) Min alloc-odr0-2 248.00 ( 0.00%) 231.00 ( 6.85%) Min alloc-odr0-4 209.00 ( 0.00%) 192.00 ( 8.13%) Min alloc-odr0-8 181.00 ( 0.00%) 166.00 ( 8.29%) Min alloc-odr0-16 168.00 ( 0.00%) 154.00 ( 8.33%) Min alloc-odr0-32 161.00 ( 0.00%) 148.00 ( 8.07%) Min alloc-odr0-64 158.00 ( 0.00%) 145.00 ( 8.23%) Min alloc-odr0-128 156.00 ( 0.00%) 143.00 ( 8.33%) Min alloc-odr0-256 168.00 ( 0.00%) 154.00 ( 8.33%) Min alloc-odr0-512 178.00 ( 0.00%) 167.00 ( 6.18%) Min alloc-odr0-1024 186.00 ( 0.00%) 174.00 ( 6.45%) Min alloc-odr0-2048 192.00 ( 0.00%) 180.00 ( 6.25%) Min alloc-odr0-4096 198.00 ( 0.00%) 184.00 ( 7.07%) Min alloc-odr0-8192 200.00 ( 0.00%) 188.00 ( 6.00%) Min alloc-odr0-16384 201.00 ( 0.00%) 188.00 ( 6.47%) Min free-odr0-1 189.00 ( 0.00%) 180.00 ( 4.76%) Min free-odr0-2 132.00 ( 0.00%) 126.00 ( 4.55%) Min free-odr0-4 104.00 ( 0.00%) 99.00 ( 4.81%) Min free-odr0-8 90.00 ( 0.00%) 85.00 ( 5.56%) Min free-odr0-16 84.00 ( 0.00%) 80.00 ( 4.76%) Min free-odr0-32 80.00 ( 0.00%) 76.00 ( 5.00%) Min free-odr0-64 78.00 ( 0.00%) 74.00 ( 5.13%) Min free-odr0-128 77.00 ( 0.00%) 73.00 ( 5.19%) Min free-odr0-256 94.00 ( 0.00%) 91.00 ( 3.19%) Min free-odr0-512 108.00 ( 0.00%) 112.00 ( -3.70%) Min free-odr0-1024 115.00 ( 0.00%) 118.00 ( -2.61%) Min free-odr0-2048 120.00 ( 0.00%) 125.00 ( -4.17%) Min free-odr0-4096 123.00 ( 0.00%) 129.00 ( -4.88%) Min free-odr0-8192 126.00 ( 0.00%) 130.00 ( -3.17%) Min free-odr0-16384 126.00 ( 0.00%) 131.00 ( -3.97%) Note that the free paths for large numbers of pages is impacted as the debugging cost gets shifted into that path when the page data is no longer necessarily cache-hot. Signed-off-by: -
Mel Gorman authored
Every page free checks a number of page fields for validity. This catches premature frees and corruptions but it is also expensive. This patch weakens the debugging check by checking PCP pages at the time they are drained from the PCP list. This will trigger the bug but the site that freed the corrupt page will be lost. To get the full context, a kernel rebuild with DEBUG_VM is necessary. [akpm@linux-foundation.org: fix build] Signed-off-by:
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Vlastimil Babka authored
An important function for cpusets is cpuset_node_allowed(), which optimizes on the fact if there's a single root CPU set, it must be trivially allowed. But the check "nr_cpusets() <= 1" doesn't use the cpusets_enabled_key static key the right way where static keys eliminate branching overhead with jump labels. This patch converts it so that static key is used properly. It's also switched to the new static key API and the checking functions are converted to return bool instead of int. We also provide a new variant __cpuset_zone_allowed() which expects that the static key check was already done and they key was enabled. This is needed for get_page_from_freelist() where we want to also avoid the relatively slower check when ALLOC_CPUSET is not set in alloc_flags. The impact on the page allocator microbenchmark is less than expected but the cleanup in itself is worthwhile. 4.6.0-rc2 4.6.0-rc2 multcheck-v1r20 cpuset-v1r20 Min alloc-odr0-1 348.00 ( 0.00%) 348.00 ( 0.00%) Min alloc-odr0-2 254.00 ( 0.00%) 254.00 ( 0.00%) Min alloc-odr0-4 213.00 ( 0.00%) 213.00 ( 0.00%) Min alloc-odr0-8 186.00 ( 0.00%) 183.00 ( 1.61%) Min alloc-odr0-16 173.00 ( 0.00%) 171.00 ( 1.16%) Min alloc-odr0-32 166.00 ( 0.00%) 163.00 ( 1.81%) Min alloc-odr0-64 162.00 ( 0.00%) 159.00 ( 1.85%) Min alloc-odr0-128 160.00 ( 0.00%) 157.00 ( 1.88%) Min alloc-odr0-256 169.00 ( 0.00%) 166.00 ( 1.78%) Min alloc-odr0-512 180.00 ( 0.00%) 180.00 ( 0.00%) Min alloc-odr0-1024 188.00 ( 0.00%) 187.00 ( 0.53%) Min alloc-odr0-2048 194.00 ( 0.00%) 193.00 ( 0.52%) Min alloc-odr0-4096 199.00 ( 0.00%) 198.00 ( 0.50%) Min alloc-odr0-8192 202.00 ( 0.00%) 201.00 ( 0.50%) Min alloc-odr0-16384 203.00 ( 0.00%) 202.00 ( 0.49%) Signed-off-by:Zefan Li <lizefan@huawei.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by:
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Mel Gorman authored
The function call overhead of get_pfnblock_flags_mask() is measurable in the page free paths. This patch uses an inlined version that is faster. Signed-off-by:
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Mel Gorman authored
The original count is never reused so it can be removed. Signed-off-by:
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Mel Gorman authored
Check without side-effects should be easier to maintain. It also removes the duplicated cpupid and flags reset done in !DEBUG_VM variant of both free_pcp_prepare() and then bulkfree_pcp_prepare(). Finally, it enables the next patch. It shouldn't result in new branches, thanks to inlining of the check. !DEBUG_VM bloat-o-meter: add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-27 (-27) function old new delta __free_pages_ok 748 739 -9 free_pcppages_bulk 1403 1385 -18 DEBUG_VM: add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-28 (-28) function old new delta free_pages_prepare 806 778 -28 This is also slightly faster because cpupid information is not set on tail pages so we can avoid resets there. Signed-off-by:
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Mel Gorman authored
From: Vlastimil Babka <vbabka@suse.cz> !DEBUG_VM size and bloat-o-meter: add/remove: 1/0 grow/shrink: 0/2 up/down: 124/-370 (-246) function old new delta free_pages_check_bad - 124 +124 free_pcppages_bulk 1288 1171 -117 __free_pages_ok 948 695 -253 DEBUG_VM: add/remove: 1/0 grow/shrink: 0/1 up/down: 124/-214 (-90) function old new delta free_pages_check_bad - 124 +124 free_pages_prepare 1112 898 -214 [akpm@linux-foundation.org: fix whitespace] Signed-off-by:
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Mel Gorman authored
Every page allocated or freed is checked for sanity to avoid corruptions that are difficult to detect later. A bad page could be due to a number of fields. Instead of using multiple branches, this patch combines multiple fields into a single branch. A detailed check is only necessary if that check fails. 4.6.0-rc2 4.6.0-rc2 initonce-v1r20 multcheck-v1r20 Min alloc-odr0-1 359.00 ( 0.00%) 348.00 ( 3.06%) Min alloc-odr0-2 260.00 ( 0.00%) 254.00 ( 2.31%) Min alloc-odr0-4 214.00 ( 0.00%) 213.00 ( 0.47%) Min alloc-odr0-8 186.00 ( 0.00%) 186.00 ( 0.00%) Min alloc-odr0-16 173.00 ( 0.00%) 173.00 ( 0.00%) Min alloc-odr0-32 165.00 ( 0.00%) 166.00 ( -0.61%) Min alloc-odr0-64 162.00 ( 0.00%) 162.00 ( 0.00%) Min alloc-odr0-128 161.00 ( 0.00%) 160.00 ( 0.62%) Min alloc-odr0-256 170.00 ( 0.00%) 169.00 ( 0.59%) Min alloc-odr0-512 181.00 ( 0.00%) 180.00 ( 0.55%) Min alloc-odr0-1024 190.00 ( 0.00%) 188.00 ( 1.05%) Min alloc-odr0-2048 196.00 ( 0.00%) 194.00 ( 1.02%) Min alloc-odr0-4096 202.00 ( 0.00%) 199.00 ( 1.49%) Min alloc-odr0-8192 205.00 ( 0.00%) 202.00 ( 1.46%) Min alloc-odr0-16384 205.00 ( 0.00%) 203.00 ( 0.98%) Again, the benefit is marginal but avoiding excessive branches is important. Ideally the paths would not have to check these conditions at all but regrettably abandoning the tests would make use-after-free bugs much harder to detect. Signed-off-by: -
Mel Gorman authored
The classzone_idx can be inferred from preferred_zoneref so remove the unnecessary field and save stack space. Signed-off-by:
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Mel Gorman authored
The allocator fast path looks up the first usable zone in a zonelist and then get_page_from_freelist does the same job in the zonelist iterator. This patch preserves the necessary information. 4.6.0-rc2 4.6.0-rc2 fastmark-v1r20 initonce-v1r20 Min alloc-odr0-1 364.00 ( 0.00%) 359.00 ( 1.37%) Min alloc-odr0-2 262.00 ( 0.00%) 260.00 ( 0.76%) Min alloc-odr0-4 214.00 ( 0.00%) 214.00 ( 0.00%) Min alloc-odr0-8 186.00 ( 0.00%) 186.00 ( 0.00%) Min alloc-odr0-16 173.00 ( 0.00%) 173.00 ( 0.00%) Min alloc-odr0-32 165.00 ( 0.00%) 165.00 ( 0.00%) Min alloc-odr0-64 161.00 ( 0.00%) 162.00 ( -0.62%) Min alloc-odr0-128 159.00 ( 0.00%) 161.00 ( -1.26%) Min alloc-odr0-256 168.00 ( 0.00%) 170.00 ( -1.19%) Min alloc-odr0-512 180.00 ( 0.00%) 181.00 ( -0.56%) Min alloc-odr0-1024 190.00 ( 0.00%) 190.00 ( 0.00%) Min alloc-odr0-2048 196.00 ( 0.00%) 196.00 ( 0.00%) Min alloc-odr0-4096 202.00 ( 0.00%) 202.00 ( 0.00%) Min alloc-odr0-8192 206.00 ( 0.00%) 205.00 ( 0.49%) Min alloc-odr0-16384 206.00 ( 0.00%) 205.00 ( 0.49%) The benefit is negligible and the results are within the noise but each cycle counts. Signed-off-by: -
Mel Gorman authored
Watermarks have to be checked on every allocation including the number of pages being allocated and whether reserves can be accessed. The reserves only matter if memory is limited and the free_pages adjustment only applies to high-order pages. This patch adds a shortcut for order-0 pages that avoids numerous calculations if there is plenty of free memory yielding the following performance difference in a page allocator microbenchmark; 4.6.0-rc2 4.6.0-rc2 optfair-v1r20 fastmark-v1r20 Min alloc-odr0-1 380.00 ( 0.00%) 364.00 ( 4.21%) Min alloc-odr0-2 273.00 ( 0.00%) 262.00 ( 4.03%) Min alloc-odr0-4 227.00 ( 0.00%) 214.00 ( 5.73%) Min alloc-odr0-8 196.00 ( 0.00%) 186.00 ( 5.10%) Min alloc-odr0-16 183.00 ( 0.00%) 173.00 ( 5.46%) Min alloc-odr0-32 173.00 ( 0.00%) 165.00 ( 4.62%) Min alloc-odr0-64 169.00 ( 0.00%) 161.00 ( 4.73%) Min alloc-odr0-128 169.00 ( 0.00%) 159.00 ( 5.92%) Min alloc-odr0-256 180.00 ( 0.00%) 168.00 ( 6.67%) Min alloc-odr0-512 190.00 ( 0.00%) 180.00 ( 5.26%) Min alloc-odr0-1024 198.00 ( 0.00%) 190.00 ( 4.04%) Min alloc-odr0-2048 204.00 ( 0.00%) 196.00 ( 3.92%) Min alloc-odr0-4096 209.00 ( 0.00%) 202.00 ( 3.35%) Min alloc-odr0-8192 213.00 ( 0.00%) 206.00 ( 3.29%) Min alloc-odr0-16384 214.00 ( 0.00%) 206.00 ( 3.74%) Signed-off-by: -
Mel Gorman authored
The fair zone allocation policy is not without cost but it can be reduced slightly. This patch removes an unnecessary local variable, checks the likely conditions of the fair zone policy first, uses a bool instead of a flags check and falls through when a remote node is encountered instead of doing a full restart. The benefit is marginal but it's there 4.6.0-rc2 4.6.0-rc2 decstat-v1r20 optfair-v1r20 Min alloc-odr0-1 377.00 ( 0.00%) 380.00 ( -0.80%) Min alloc-odr0-2 273.00 ( 0.00%) 273.00 ( 0.00%) Min alloc-odr0-4 226.00 ( 0.00%) 227.00 ( -0.44%) Min alloc-odr0-8 196.00 ( 0.00%) 196.00 ( 0.00%) Min alloc-odr0-16 183.00 ( 0.00%) 183.00 ( 0.00%) Min alloc-odr0-32 175.00 ( 0.00%) 173.00 ( 1.14%) Min alloc-odr0-64 172.00 ( 0.00%) 169.00 ( 1.74%) Min alloc-odr0-128 170.00 ( 0.00%) 169.00 ( 0.59%) Min alloc-odr0-256 183.00 ( 0.00%) 180.00 ( 1.64%) Min alloc-odr0-512 191.00 ( 0.00%) 190.00 ( 0.52%) Min alloc-odr0-1024 199.00 ( 0.00%) 198.00 ( 0.50%) Min alloc-odr0-2048 204.00 ( 0.00%) 204.00 ( 0.00%) Min alloc-odr0-4096 210.00 ( 0.00%) 209.00 ( 0.48%) Min alloc-odr0-8192 213.00 ( 0.00%) 213.00 ( 0.00%) Min alloc-odr0-16384 214.00 ( 0.00%) 214.00 ( 0.00%) The benefit is marginal at best but one of the most important benefits, avoiding a second search when falling back to another node is not triggered by this particular test so the benefit for some corner cases is understated. Signed-off-by: -
Mel Gorman authored
The page allocator fast path checks page multiple times unnecessarily. This patch avoids all the slowpath checks if the first allocation attempt succeeds. Signed-off-by:
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Mel Gorman authored
When bulk freeing pages from the per-cpu lists the zone is checked for isolated pageblocks on every release. This patch checks it once per drain. [mgorman@techsingularity.net: fix locking radce, per Vlastimil] Signed-off-by:
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Mel Gorman authored
__GFP_HARDWALL only has meaning in the context of cpusets but the fast path always applies the flag on the first attempt. Move the manipulations into the cpuset paths where they will be masked by a static branch in the common case. With the other micro-optimisations in this series combined, the impact on a page allocator microbenchmark is 4.6.0-rc2 4.6.0-rc2 decstat-v1r20 micro-v1r20 Min alloc-odr0-1 381.00 ( 0.00%) 377.00 ( 1.05%) Min alloc-odr0-2 275.00 ( 0.00%) 273.00 ( 0.73%) Min alloc-odr0-4 229.00 ( 0.00%) 226.00 ( 1.31%) Min alloc-odr0-8 199.00 ( 0.00%) 196.00 ( 1.51%) Min alloc-odr0-16 186.00 ( 0.00%) 183.00 ( 1.61%) Min alloc-odr0-32 179.00 ( 0.00%) 175.00 ( 2.23%) Min alloc-odr0-64 174.00 ( 0.00%) 172.00 ( 1.15%) Min alloc-odr0-128 172.00 ( 0.00%) 170.00 ( 1.16%) Min alloc-odr0-256 181.00 ( 0.00%) 183.00 ( -1.10%) Min alloc-odr0-512 193.00 ( 0.00%) 191.00 ( 1.04%) Min alloc-odr0-1024 201.00 ( 0.00%) 199.00 ( 1.00%) Min alloc-odr0-2048 206.00 ( 0.00%) 204.00 ( 0.97%) Min alloc-odr0-4096 212.00 ( 0.00%) 210.00 ( 0.94%) Min alloc-odr0-8192 215.00 ( 0.00%) 213.00 ( 0.93%) Min alloc-odr0-16384 216.00 ( 0.00%) 214.00 ( 0.93%) Signed-off-by: -
Mel Gorman authored
The current reset unnecessarily clears flags and makes pointless calculations. Signed-off-by:
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Mel Gorman authored
page is guaranteed to be set before it is read with or without the initialisation. [akpm@linux-foundation.org: fix warning] Signed-off-by:
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Mel Gorman authored
Signed-off-by:
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Mel Gorman authored
zonelist here is a copy of a struct field that is used once. Ditch it. Signed-off-by:
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Mel Gorman authored
The number of zones skipped to a zone expiring its fair zone allocation quota is irrelevant. Convert to bool. Signed-off-by:
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Mel Gorman authored
alloc_flags is a bitmask of flags but it is signed which does not necessarily generate the best code depending on the compiler. Even without an impact, it makes more sense that this be unsigned. Signed-off-by:
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Mel Gorman authored
Pageblocks have an associated bitmap to store migrate types and whether the pageblock should be skipped during compaction. The bitmap may be associated with a memory section or a zone but the zone is looked up unconditionally. The compiler should optimise this away automatically so this is a cosmetic patch only in many cases. Signed-off-by:
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Mel Gorman authored
__dec_zone_state is cheaper to use for removing an order-0 page as it has fewer conditions to check. The performance difference on a page allocator microbenchmark is; 4.6.0-rc2 4.6.0-rc2 optiter-v1r20 decstat-v1r20 Min alloc-odr0-1 382.00 ( 0.00%) 381.00 ( 0.26%) Min alloc-odr0-2 282.00 ( 0.00%) 275.00 ( 2.48%) Min alloc-odr0-4 233.00 ( 0.00%) 229.00 ( 1.72%) Min alloc-odr0-8 203.00 ( 0.00%) 199.00 ( 1.97%) Min alloc-odr0-16 188.00 ( 0.00%) 186.00 ( 1.06%) Min alloc-odr0-32 182.00 ( 0.00%) 179.00 ( 1.65%) Min alloc-odr0-64 177.00 ( 0.00%) 174.00 ( 1.69%) Min alloc-odr0-128 175.00 ( 0.00%) 172.00 ( 1.71%) Min alloc-odr0-256 184.00 ( 0.00%) 181.00 ( 1.63%) Min alloc-odr0-512 197.00 ( 0.00%) 193.00 ( 2.03%) Min alloc-odr0-1024 203.00 ( 0.00%) 201.00 ( 0.99%) Min alloc-odr0-2048 209.00 ( 0.00%) 206.00 ( 1.44%) Min alloc-odr0-4096 214.00 ( 0.00%) 212.00 ( 0.93%) Min alloc-odr0-8192 218.00 ( 0.00%) 215.00 ( 1.38%) Min alloc-odr0-16384 219.00 ( 0.00%) 216.00 ( 1.37%) Signed-off-by: -
Mel Gorman authored
The page allocator iterates through a zonelist for zones that match the addressing limitations and nodemask of the caller but many allocations will not be restricted. Despite this, there is always functional call overhead which builds up. This patch inlines the optimistic basic case and only calls the iterator function for the complex case. A hindrance was the fact that cpuset_current_mems_allowed is used in the fastpath as the allowed nodemask even though all nodes are allowed on most systems. The patch handles this by only considering cpuset_current_mems_allowed if a cpuset exists. As well as being faster in the fast-path, this removes some junk in the slowpath. The performance difference on a page allocator microbenchmark is; 4.6.0-rc2 4.6.0-rc2 statinline-v1r20 optiter-v1r20 Min alloc-odr0-1 412.00 ( 0.00%) 382.00 ( 7.28%) Min alloc-odr0-2 301.00 ( 0.00%) 282.00 ( 6.31%) Min alloc-odr0-4 247.00 ( 0.00%) 233.00 ( 5.67%) Min alloc-odr0-8 215.00 ( 0.00%) 203.00 ( 5.58%) Min alloc-odr0-16 199.00 ( 0.00%) 188.00 ( 5.53%) Min alloc-odr0-32 191.00 ( 0.00%) 182.00 ( 4.71%) Min alloc-odr0-64 187.00 ( 0.00%) 177.00 ( 5.35%) Min alloc-odr0-128 185.00 ( 0.00%) 175.00 ( 5.41%) Min alloc-odr0-256 193.00 ( 0.00%) 184.00 ( 4.66%) Min alloc-odr0-512 207.00 ( 0.00%) 197.00 ( 4.83%) Min alloc-odr0-1024 213.00 ( 0.00%) 203.00 ( 4.69%) Min alloc-odr0-2048 220.00 ( 0.00%) 209.00 ( 5.00%) Min alloc-odr0-4096 226.00 ( 0.00%) 214.00 ( 5.31%) Min alloc-odr0-8192 229.00 ( 0.00%) 218.00 ( 4.80%) Min alloc-odr0-16384 229.00 ( 0.00%) 219.00 ( 4.37%) perf indicated that next_zones_zonelist disappeared in the profile and __next_zones_zonelist did not appear. This is expected as the micro-benchmark would hit the inlined fast-path every time. Signed-off-by: -
Mel Gorman authored
zone_statistics has one call-site but it's a public function. Make it static and inline. The performance difference on a page allocator microbenchmark is; 4.6.0-rc2 4.6.0-rc2 statbranch-v1r20 statinline-v1r20 Min alloc-odr0-1 419.00 ( 0.00%) 412.00 ( 1.67%) Min alloc-odr0-2 305.00 ( 0.00%) 301.00 ( 1.31%) Min alloc-odr0-4 250.00 ( 0.00%) 247.00 ( 1.20%) Min alloc-odr0-8 219.00 ( 0.00%) 215.00 ( 1.83%) Min alloc-odr0-16 203.00 ( 0.00%) 199.00 ( 1.97%) Min alloc-odr0-32 195.00 ( 0.00%) 191.00 ( 2.05%) Min alloc-odr0-64 191.00 ( 0.00%) 187.00 ( 2.09%) Min alloc-odr0-128 189.00 ( 0.00%) 185.00 ( 2.12%) Min alloc-odr0-256 198.00 ( 0.00%) 193.00 ( 2.53%) Min alloc-odr0-512 210.00 ( 0.00%) 207.00 ( 1.43%) Min alloc-odr0-1024 216.00 ( 0.00%) 213.00 ( 1.39%) Min alloc-odr0-2048 221.00 ( 0.00%) 220.00 ( 0.45%) Min alloc-odr0-4096 227.00 ( 0.00%) 226.00 ( 0.44%) Min alloc-odr0-8192 232.00 ( 0.00%) 229.00 ( 1.29%) Min alloc-odr0-16384 232.00 ( 0.00%) 229.00 ( 1.29%) Signed-off-by: -
Mel Gorman authored
zone_statistics has more branches than it really needs to take an unlikely GFP flag into account. Reduce the number and annotate the unlikely flag. The performance difference on a page allocator microbenchmark is; 4.6.0-rc2 4.6.0-rc2 nocompound-v1r10 statbranch-v1r10 Min alloc-odr0-1 417.00 ( 0.00%) 419.00 ( -0.48%) Min alloc-odr0-2 308.00 ( 0.00%) 305.00 ( 0.97%) Min alloc-odr0-4 253.00 ( 0.00%) 250.00 ( 1.19%) Min alloc-odr0-8 221.00 ( 0.00%) 219.00 ( 0.90%) Min alloc-odr0-16 205.00 ( 0.00%) 203.00 ( 0.98%) Min alloc-odr0-32 199.00 ( 0.00%) 195.00 ( 2.01%) Min alloc-odr0-64 193.00 ( 0.00%) 191.00 ( 1.04%) Min alloc-odr0-128 191.00 ( 0.00%) 189.00 ( 1.05%) Min alloc-odr0-256 200.00 ( 0.00%) 198.00 ( 1.00%) Min alloc-odr0-512 212.00 ( 0.00%) 210.00 ( 0.94%) Min alloc-odr0-1024 219.00 ( 0.00%) 216.00 ( 1.37%) Min alloc-odr0-2048 225.00 ( 0.00%) 221.00 ( 1.78%) Min alloc-odr0-4096 231.00 ( 0.00%) 227.00 ( 1.73%) Min alloc-odr0-8192 234.00 ( 0.00%) 232.00 ( 0.85%) Min alloc-odr0-16384 234.00 ( 0.00%) 232.00 ( 0.85%) Signed-off-by: -
Mel Gorman authored
The PageAnon check always checks for compound_head but this is a relatively expensive check if the caller already knows the page is a head page. This patch creates a helper and uses it in the page free path which only operates on head pages. With this patch and "Only check PageCompound for high-order pages", the performance difference on a page allocator microbenchmark is; 4.6.0-rc2 4.6.0-rc2 vanilla nocompound-v1r20 Min alloc-odr0-1 425.00 ( 0.00%) 417.00 ( 1.88%) Min alloc-odr0-2 313.00 ( 0.00%) 308.00 ( 1.60%) Min alloc-odr0-4 257.00 ( 0.00%) 253.00 ( 1.56%) Min alloc-odr0-8 224.00 ( 0.00%) 221.00 ( 1.34%) Min alloc-odr0-16 208.00 ( 0.00%) 205.00 ( 1.44%) Min alloc-odr0-32 199.00 ( 0.00%) 199.00 ( 0.00%) Min alloc-odr0-64 195.00 ( 0.00%) 193.00 ( 1.03%) Min alloc-odr0-128 192.00 ( 0.00%) 191.00 ( 0.52%) Min alloc-odr0-256 204.00 ( 0.00%) 200.00 ( 1.96%) Min alloc-odr0-512 213.00 ( 0.00%) 212.00 ( 0.47%) Min alloc-odr0-1024 219.00 ( 0.00%) 219.00 ( 0.00%) Min alloc-odr0-2048 225.00 ( 0.00%) 225.00 ( 0.00%) Min alloc-odr0-4096 230.00 ( 0.00%) 231.00 ( -0.43%) Min alloc-odr0-8192 235.00 ( 0.00%) 234.00 ( 0.43%) Min alloc-odr0-16384 235.00 ( 0.00%) 234.00 ( 0.43%) Min free-odr0-1 215.00 ( 0.00%) 191.00 ( 11.16%) Min free-odr0-2 152.00 ( 0.00%) 136.00 ( 10.53%) Min free-odr0-4 119.00 ( 0.00%) 107.00 ( 10.08%) Min free-odr0-8 106.00 ( 0.00%) 96.00 ( 9.43%) Min free-odr0-16 97.00 ( 0.00%) 87.00 ( 10.31%) Min free-odr0-32 91.00 ( 0.00%) 83.00 ( 8.79%) Min free-odr0-64 89.00 ( 0.00%) 81.00 ( 8.99%) Min free-odr0-128 88.00 ( 0.00%) 80.00 ( 9.09%) Min free-odr0-256 106.00 ( 0.00%) 95.00 ( 10.38%) Min free-odr0-512 116.00 ( 0.00%) 111.00 ( 4.31%) Min free-odr0-1024 125.00 ( 0.00%) 118.00 ( 5.60%) Min free-odr0-2048 133.00 ( 0.00%) 126.00 ( 5.26%) Min free-odr0-4096 136.00 ( 0.00%) 130.00 ( 4.41%) Min free-odr0-8192 138.00 ( 0.00%) 130.00 ( 5.80%) Min free-odr0-16384 137.00 ( 0.00%) 130.00 ( 5.11%) There is a sizable boost to the free allocator performance. While there is an apparent boost on the allocation side, it's likely a co-incidence or due to the patches slightly reducing cache footprint. Signed-off-by:
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