Linux mips highmem. void * kmap_atomic_pfn ( unsigned long pfn ) Definition at line 101 of file highmem. It does not have highlighting. struct page * kmap_atomic_to_page ( void * ptr ) read Definition at line 117 of file highmem. burton@xxxxxxxxxx> Date: Tue, 1 Mar 2016 02:37:55 +0000 Cc: Paul Burton <paul. 18 which by now is an almost 3 year old antique doesn't know about that and will happily Re: [PATCH v2] MIPS: Kernel crashes on boot with SPARSEMEM + HIGHMEM enabled -- Linux MIPS Kernel Archive Apr 10, 2015 · Commit 8b5fe5e54b47 ("MIPS: Fix race condition in lazy cache flushing. The performance penalty is on I/O or any sort of kernel activity on highmem pages. persson@xxxxxxxx>, "Steven J. The time now is 01:46 PM. Hill wrote: > On 04/10/2015 09:31 AM, Lars Persson wrote: > > Ralf, > > > > I came to think that also non-executable mappings for highmem pages > > could reach the flushing code in __update_cache () and trigger an > > OOPS. Aug 20, 2014 · Hello, * I have a MIPS based system having 512MB RAM. ") > triggered NULL pointer dereferences on systems with HIGHMEM. At a minimum, this Re: HIGHMEM -- Linux MIPS Kernel ArchiveIssue #3 - As I recall the TX4937's H3 core is suffering from cache aliases. Yegoshin@xxxxxxxxxx> Provide hooks that allow architectures with aliasing cache to align mapping address of high pages according to their color. h> # May 6, 2015 · [OpenWrt-Devel] [PATCH 1/4] kernel: mips jump only works with memory less then 256mb. To: <linux-mips@xxxxxxxxxxxxxx> Subject: [PATCH 0/4] MIPS cache & highmem fixes From: Paul Burton <paul. 18) for R4000 processor. net 2003-10-08 22:00:33 UTC Permalink Hello Ralf, This document contains information that is proprietary to MIPS Tech, LLC, a Wave Computing company (“MIPS”) and MIPS’ affiliates as applicable. org>, <imx@ts. h Sep 19, 2020 · arch/mips/Kconfig | 1 arch/mips/include/asm/highmem. 9-rc using KDAB Codebrowser which provides IDE like features for browsing C, C++, Rust & Dart code in your browser code / linux / torvalds / linux / 25e81f925d4be0a0f60520e1c3c1b5af744404e1 / . This ensures that -mlong-calls is not needed on systems with more than 256M RAM. ] > > The MIPS DMA coherency functions do not work properly (i. Nikolaus Schaller" <hns@xxxxxxxxxxxxx> Date: Sun, 10 Jan 2021 12:53:10 +0100 Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>, tglx@xxxxxxxxxxxxx, airlied@xxxxxxxx, airlied@xxxxxxxxxx, akpm@xxxxxxxxxxxxxxxxxxxx, arnd@xxxxxxxx, bcrl@xxxxxxxxx, bigeasy@xxxxxxxxxxxxx [prev in list] [next in list] [prev in thread] [next in thread] List: linux-kernel Subject: [PATCH 0/5] MIPS: HIGHMEM DMA on noncoherent MIPS32 processors From: Kevin Cernekee <cernekee () gmail ! com> Date: 2010-09-07 4:03:42 Message-ID: ea0143cf318153e615b660cb0210f464 () localhost [Download RAW message or body] I had some time this weekend On Mon, 2015-04-13 at 19:08 +0200, Steven J. The code for that isn Re: [patch V3 13/37] mips/mm/highmem: Switch to generic kmap atomic — Linux Sparc Kernel Archive Dear AVM: Please activate CONFIG_IKCONFIG for all kernels and modules. h> 4#include < linux/smp. [patch V2 09/18] mips/mm/highmem: Switch to generic kmap atomic User process performance is identical. h> #include <linux/init. Jul 23, 2024 · 文章浏览阅读7. Sep 10, 2025 · To: Arnd Bergmann <arnd@xxxxxxxx> Subject: Re: [TECH TOPIC] Reaching consensus on CONFIG_HIGHMEM phaseout From: Richard Weinberger <richard@xxxxxx> Date: Wed, 10 Sep 2025 16:04:33 +0200 (CEST) Cc: ksummit <ksummit@xxxxxxxxxxxxxxx>, linux-kernel <linux-kernel@xxxxxxxxxxxxxxx>, linux-arm-kernel <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>, linuxppc-dev@xxxxxxxxxxxxxxxx, linux-mips <linux-mips CoCalc Share ServerReal-time collaboration for Jupyter Notebooks, Linux Terminals, LaTeX, VS Code, R IDE, and more, all in one place. 0 #include <linux/compiler. h> 6#include <asm/tlbflush. This means the kernel needs to start using temporary mappings of the pieces of physical memory that it wants to access. / include / asm-mips / highmem. git, which uses the new > dma-mapping-common. e. . > > The problem was caused by not clearing the PG_dcache_dirty flag in > flush_icache_page () and thus we enter __update_cache () that lacks > support for HIGHMEM. Thanks! 1 /* 2 * highmem. unal@xxxxxxxxxx, christophe. p. kernel. arora@xxxxxxxxxx, arnd@xxxxxxxx, chester. void __init kmap_init ( void ) Definition at line 130 of file highmem. Handling those efficiently for highmem is not easily possible and so we don't even try. 1k次。本文详细解析了Linux内核如何管理并映射高端内存，包括高端内存的概念、映射方式以及MIPS平台的特殊管理策略，强调了不同映射方法的特点和适用场景。 nv-tegra. What is HIGHMEM? The Linux kernel virtualizes its memory. V" <aneesh. nvidia. void kunmap ( struct page * page ) Definition at High Memory Support found in arch/mips/Kconfig The configuration item CONFIG_HIGHMEM: From: Chuanhong Guo <gch981213@xxxxxxxxx> mt7621 has the following memory map: 0x0-0x1c000000: lower 448m memory 0x1c000000-0x2000000: peripheral registers 0x20000000-0x2400000: higher 64m memory detect_memory_region in arch/mips/kernel/setup. Such architectures may enforce similar coloring of low- and high-memory page mappings and reuse existing cache management functions to support highmem. when enable HIGHMEM use long jump wengbj Wed, 06 May 2015 19:29:12 -0700 History History 17 lines (15 loc) · 579 Bytes master openwrt / target / linux / generic / patches-4. This code is based on the implementation of similar feature for MIPS by Leonid Yegoshin <Leonid. Could you add this to the Re: sparsemem support for mips with highmem -- Linux MIPS Kernel Archive [PATCH v4 RESEND 4/7] MIPS: HIGHMEM DMA on noncoherent MIPS32 processors Discussion: mips 32 bit HIGHMEM support e***@velocitus. [PATCH 0/8] xtensa: highmem support on cores with aliasing cache -- Linux MIPS Kernel Archive Re: [PATCH v3 2/2] MIPS: HIGHMEM DMA on noncoherent MIPS32 processors Warning: This file is not a C or C++ file. 11-rt29-fixes / . h blob: 4d6bd5c31c7bf38f5551d08a2db3b980ed1cac37 [file] [log] [blame] Vortex86DX3 supports 2GB DDR3 memory. 18, userspace applications are very likely to crash with a SIGILL / SIGSEGV / SIGBUS signal. 4. [PATCH v2 11/13] arch, mm: streamline HIGHMEM freeing -- Linux MIPS Kernel Archive [patch V2 16/18] sched: highmem: Store local kmaps in task struct -- Linux MIPS Kernel Archive References: [PATCH 1/9] arch/mips/alchemy: Correct code taking the size of a pointer From: Julia Lawall Help in enabling HIGHMEM support From: Anoop P. Disabling highmem in the kernel, or reducing the RAM amount to 256 MiB in u-boot's command line, make those issues [patch V2 09/18] mips/mm/highmem: Switch to generic kmap atomic All times are GMT -5. de>, Linus Walleij Feb 27, 2020 · And, sometimes, high memory affects development decisions being made today. kernel oops) > when HIGHMEM pages are passed in as arguments. 6. org>, <linux-mips@r. ") triggered NULL pointer dereferences on systems with HIGHMEM. In this architecture, traditionally the Linux kernel has split the 4GB of virtual memory address space into 3GB for user programs and 1GB for the kernel. highmem When a file is accessed on a Linux system, the kernel loads an inode structure describing it; those structures are cached, since a file that is accessed once will frequently be accessed again in the near future. c | 77 ------------- arch/mips/mm/init. How do I measure the penalty of highmem on kernel modules? Since the > code and data for modules resides in highmem, the kernel has to > constantly map and unmap while running inside the modules? To: Max Filippov < jcmvbkbc@xxxxxxxxx > Subject: Re: [PATCH v3 1/2] mm/highmem: make kmap cache coloring aware From: Andrew Morton < akpm@xxxxxxxxxxxxxxxxxxxx > Date: Fri, 1 Aug 2014 13:10:49 -0700 Cc: linux-xtensa@xxxxxxxxxxxxxxxx, Chris Zankel < chris@xxxxxxxxxx >, Marc Gauthier < marc@xxxxxxxxxxx >, linux-mm@xxxxxxxxx, linux-arch@xxxxxxxxxxxxxxx, linux-mips@xxxxxxxxxxxxxx, linux-kernel [prev in list] [next in list] [prev in thread] [next in thread] List: linux-mm Subject: Re: sparsemem support for mips with highmem From: Andy Whitcroft <apw () shadowen ! org> Date: 2008-08-26 9:09:36 Message-ID: 20080826090936. c blob: d08e6d7d533b049a607fbce4513c903acdc73472 [file] [log] [blame] > Commit 8b5fe5e54b47 ("MIPS: Fix race condition in lazy cache flushing. h blob: 8cf598402492c2d2394aeb0fc2add6f7f8f57724 [file] [log] [blame] May 13, 2016 · The following patch will expose __update_cache to highmem pages. linux-mips. Sep 22, 2025 · mm/highmem. org>, <linux-arm-kernel@ts. org Apr 21, 2022 · This is the second post in the Linux kernel series. ozlabs. Inode-cache shrinking vs. While compilation was fine but the kernel boot up panics in “init”. ") Such architectures may enforce similar coloring of low- and high-memory page mappings and reuse existing cache management functions to support highmem. High Memory Handling ¶ By: Peter Zijlstra <a. This patch uses the PPC > approach of calling kmap_atomic () with IRQs disabled to temporarily map To: linux-xtensa@xxxxxxxxxxxxxxxx Subject: [PATCH v4 1/2] mm/highmem: make kmap cache coloring aware From: Max Filippov < jcmvbkbc@xxxxxxxxx > Date: Sat, 2 Aug 2014 05:11:38 +0400 Cc: Chris Zankel < chris@xxxxxxxxxx >, Marc Gauthier < marc@xxxxxxxxxxx >, linux-mm@xxxxxxxxx, linux-arch@xxxxxxxxxxxxxxx, linux-mips@xxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, David Rientjes < rientjes@xxxxxxxxxx Commit 8b5fe5e54b47 ("MIPS: Fix race condition in lazy cache flushing. c | 3 arch/nds32/Kconfig. nl> What Is High Memory? Temporary Virtual Mappings Cost of Temporary Mappings i386 PAE Functions What Is High Memory? ¶ High memory (highmem) is used when the size of physical memory approaches or exceeds the maximum size of virtual memory. The kernel also supports highmem on ARMv4, ARMv5, ARMv6, PPC4xx, PPC82xx, PPC83xx, ARC, CSKY, Microblaze and Xtensa, as well as additional MIPS SoCs, but so far I could not find any indication of any such machine with more than 1GB that keeps getting kernel updates. / arch / mips / mm / highmem. h | 21 ++- arch/nds32/mm/Makefile | 1 [patch V3 08/37] x86/mm/highmem: Use generic kmap atomic implementation -- Linux MIPS Kernel Archive A desktop-oriented Linux kernel fork. > > > > Until the highmem patches are merged we should block highmem pages in > > __update_cache (). / mips-disable-highmem-on-rt. leroy@roup. [PATCH v2 2/6] MIPS: pfn_valid () is broken on low memory HIGHMEM systems [patch V2 09/18] mips/mm/highmem: Switch to generic kmap atomic [patch RFC 14/15] sched: highmem: Store temporary kmaps in task struct -- Linux MIPS Kernel Archive [prev in list] [next in list] [prev in thread] [next in thread] List: linux-mips Subject: RE: Problem with HIGHMEM implementation for 32 bit mips-el port From: <Rishabh () soc-soft ! com> Date: 2005-02-01 5:41:29 Message-ID: 4BF47D56A0DD2346A1B8D622C5C5902C49D06C () soc-mail ! soc-soft ! com [Download RAW message or body] Hi all, I am attaching Linux kernel source tree. To: LKML <linux-kernel@xxxxxxxxxxxxxxx> Subject: [patch RFC 15/15] mm/highmem: Provide kmap_temporary* From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Date: Sat, 19 Sep 2020 11:18:06 +0200 Cc: linux-arch@xxxxxxxxxxxxxxx, Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxx>, Paul McKenney <paulmck@xxxxxxxxxx>, x86@xxxxxxxxxx, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>, Peter Zijlstra <peterz [PATCH 1/2] MIPS: pfn_valid () is broken on low memory HIGHMEM systems -- Linux MIPS Kernel Archive [patch RFC 12/15] xtensa/mm/highmem: Switch to generic kmap atomic -- Linux MIPS Kernel Archive [patch V2 11/18] powerpc/mm/highmem: Switch to generic kmap atomic -- Linux MIPS Kernel Archive Oct 6, 2025 · Cc: Dave Hansen <dave@xxxxxxxx>, ksummit <ksummit@xxxxxxxxxxxxxxx>, linux-kernel <linux-kernel@xxxxxxxxxxxxxxx>, linux-arm-kernel <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>, linuxppc-dev <linuxppc-dev@xxxxxxxxxxxxxxxx>, linux-mips <linux-mips@xxxxxxxxxxxxxxx>, linux-mm <linux-mm@xxxxxxxxx>, imx <imx@xxxxxxxxxxxxxxx>, Christophe Leroy <christophe Discussion: [PATCH 0/8] xtensa: highmem support on cores with aliasing cache Max Filippov 2014-07-22 19:01:05 UTC Hi, Jul 6, 2014 · Mips的highmem管理可参见其官方简介： http://www. GC29207 () brain [Download RAW message or body] On Thu, Aug 14, 2008 at 04:52:34PM -0700, C Michael Sundius wrote: > fixed patch > > Typically I was on holiday when Re: [PATCH v2] MIPS: Fix max_low_pfn with disabled highmem -- Linux MIPS Kernel Archive There are currently a few incorrect assumptions made about the location and alignment of fixed memory mappings that lead to random crashes when using highmem with large (>4k) pages Marcin Nowakowski (3): MIPS: mm: fixed mappings: correct initialisation MIPS: highmem: ensure that we don't use more than one page for PTEs MIPS: mm: adjust PKMAP Linux将内核地址空间划分为三部分ZONE_DMA、ZONE_NORMAL和ZONE_HIGHMEM。 ZONE_DMA和ZONE_NORMAL和物理内存的地址是一一对应的，关系就是物理地址=逻辑地址-3GB（仅仅对这896M地址空间有效）。 Why highmem Currently the 32 bit x86 architecture is the most popular type of computer. h> #include <linux/highmem. com / linux-2. Linux kernel source tree. Browse the source of linux v6. h> 2#include < linux/highmem. Yegoshin@xxxxxxxxxx>. CoCalc Share ServerReal-time collaboration for Jupyter Notebooks, Linux Terminals, LaTeX, VS Code, R IDE, and more, all in one place. builtin (ascii) in rootfs to help developers. nv-tegra. Ralf -- To unsubscribe May 5, 2022 · summary refs log tree diff log msg author committer range path: root / arch / mips / bcm47xx diff options Vortex86DX3 supports 2GB DDR3 memory. A typical 32bit Linux virtual memory map is like: 0x00000000-0xbfffffff: user process (3GB) 0xc0000000-0xffffffff: kernel space (1GB) (CPU-specific vector and whatsoever are ignored here). Virtual memory addresses, which can be used by programs, are mapped to physical memory addresses. daney@xxxxxxxxxx>, "Aneesh Kumar K. More recent kernels will refuse to enable highmem on such cache configurations but something like 2. Handle them by mapping them in for the duration of the cache maintenance, just like in __flush_dcache_page. At that point it becomes impossible for the kernel to keep all of the available physical memory mapped at all times. h API. burton@xxxxxxxxxx>, Lars Persson <lars. Re: [PATCH v3 1/2] mm/highmem: make kmap cache coloring aware -- Linux MIPS Kernel Archive Since the code and data for modules resides in highmem, the kernel has to constantly map and unmap while running inside the modules? Is there a way to quantify the overhead of running with highmem enabled versus not? [prev in list] [next in list] [prev in thread] [next in thread] List: linux-kernel Subject: Re: [PATCH v3 2/2] MIPS: HIGHMEM DMA on noncoherent MIPS32 processors From: Kevin Cernekee <cernekee () gmail ! com> Date: 2010-10-13 18:01:06 Message-ID: AANLkTikinkyEu-ozyiHOhr1D4ZLwv0jZwbk=4jq_YM9J () mail ! gmail ! com [Download RAW message or body] On Wed, Oct 13, 2010 at 12:53 AM, Ralf Baechle Linux kernel source tree. On traditionally sized (for lack of a better euphemism) 32 bit systems, this meant the kernel could map all of physical memory into its address space Feb 4, 2015 · When highmem is enabled on 3. a. h> #include <linux/export. 1#include <linux/module. 6 / dd146a60cb70a843a8b3a21560fdcfb4c0c9c850 / . c | 86 +++++-------------------------------- 10 files changed, 27 insertions(+), 230 deletions(-) I did get an email from Nicolas Schichan (added to Cc here), and he is still supporting a widely deployed Kirkwood based platform that uses 1GB RAM configurations. Mar 6, 2011 · kernel / pub / scm / linux / kernel / git / paulg / 3. Re: Help in enabling HIGHMEM support From: Ralf Baechle [PATCH 1/9] arch/mips/alchemy: Correct code taking the size of a pointer From: Julia Lawall From: Julia Lawall Help in enabling HIGHMEM [PATCH resend 6/9] MIPS: pfn_valid () is broken on low memory HIGHMEM systems [patch V3 24/37] sched: highmem: Store local kmaps in task struct -- Linux MIPS Kernel Archive Adjust highmem offset to 0x10000000 to ensure that all kmalloc allocations stay within the same 256M boundary. kumar From: Leonid Yegoshin <Leonid. 6 / e2216feb37f1df65a29fb1e5ed41d9f7ba657b2c / . h: virtual kernel memory mappings for high memory 3 * 4 * Used in CONFIG_HIGHMEM systems for memory pages which To: Dave Hansen <dave@xxxxxxxx> Subject: Re: [TECH TOPIC] Reaching consensus on CONFIG_HIGHMEM phaseout From: Richard Weinberger <richard@xxxxxx> Date: Wed, 10 Sep 2025 22:33:05 +0200 (CEST) Cc: Arnd Bergmann <arnd@xxxxxxxx>, ksummit <ksummit@xxxxxxxxxxxxxxx>, linux-kernel <linux-kernel@xxxxxxxxxxxxxxx>, linux-arm-kernel <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>, linuxppc-dev <linuxppc-dev Jul 23, 2024 · 即按VA=PA+PAGE_OFFSET公式映射的空间最大只有512M，其中PAGE_OFFSET=0x80000000，而在Linux中MIPS32只使用其中的256MB。 MIPS在higmem使用过程中需要注意两个问题：一是要考虑由higmem带来的整个系统性能和稳定性间的平衡，二是highmem不支持cache aliases。 五、总结 Linux kernel source tree. Thanks, I've folded this patch into the original 8b5fe5e54b47 commit. h > 3#include <linux/sched. h > 5#include <asm/fixmap. org>, <linuxppc-dev@ts. Any copying, reproducing, modifying or use of this information (in whole or in part) that is not expressly permitted in writing by MIPS or MIPS’ affiliates as applicable or an authorized third party is strictly prohibited. Hill" <Steven. cpu | 1 arch/nds32/include/asm/highmem. The first part of the series was about memblock. kernel / pub / scm / linux / kernel / git / palmer / riscv-linux / refs/tags/riscv-for-linus-4. * From user See full list on linux-mm. At that point it becomes impossible for the kernel to keep all of the available What Is High Memory? High memory (highmem) is used when the size of physical memory approaches or exceeds the maximum size of virtual memory. To: Max Filippov < jcmvbkbc@xxxxxxxxx > Subject: Re: [PATCH v2] mm/highmem: make kmap cache coloring aware From: Andrew Morton < akpm@xxxxxxxxxxxxxxxxxxxx > Date: Wed, 23 Jul 2014 14:17:21 -0700 Cc: linux-mm@xxxxxxxxx, linux-arch@xxxxxxxxxxxxxxx, linux-mips@xxxxxxxxxxxxxx, linux-xtensa@xxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx, Leonid Yegoshin < Leonid. stach@gutronix. leroy@xxxxxxxxxx, david Jul 23, 2024 · Linux将内核地址空间划分为三部分ZONE_DMA、ZONE_NORMAL和ZONE_HIGHMEM，高端内存HIGH_MEM地址空间范围为 0xF8000000 ~ 0xFFFFFFFF（896MB～1024MB）。 Symbol File Text Line // SPDX-License-Identifier: GPL-2. sverdlin@xxxxxxxxx, andreas@xxxxxxxxxxx, ankur. h | 4 arch/mips/mm/highmem. Hill@xxxxxxxxxx>, "Huacai Chen" <chenhc@xxxxxxxxxx>, David Daney <david. This week, the topic is HIGHMEM. Sep 19, 2025 · CC: <ksummit@ts. Yegoshin@xxxxxxxxxx > In-reply-to [PATCH RESEND 3/5] MIPS: pfn_valid () is broken on low memory HIGHMEM systems I am working on MIPS32 port of linux (kernel version 2. dev>, Christophe Leroy <christophe. When the size of the physical memory exceeds the (maximum) size of the virtual memory, it is not possible 8 HIGHMEM is a range of kernel's memory space, but it is NOT memory you access but it's a place where you put what you want to access. at>, Lucas Stach <l. 1 /. dev>, <linux-kernel@r. 15-rc4-riscv_fixes / . The problem was caused by not clearing the PG_dcache_dirty flag in flush_icache_page () and thus we enter __update_cache () that lacks support for HIGHMEM. Definition at line 44 of file highmem. c. zijlstra @ chello. linux. patch blob Contribute to clearlinux-pkgs/linux-iot-lts2018-preempt-rt development by creating an account on GitHub. c only adds the first memory region and isn't suitable for 512m memory detection because it may accidentally read the memory area for peripheral Linux Kernel: [PATCH 0/5] MIPS: HIGHMEM DMA on noncoherent MIPS32 processors To: Paul Cercueil <paul@xxxxxxxxxxxxxxx> Subject: Re: [patch V3 13/37] mips/mm/highmem: Switch to generic kmap atomic From: "H. 6-rt-patches / refs/heads/v3. Contribute to torvalds/linux development by creating an account on GitHub. Howlett@xxxxxxxxxx, akpm@xxxxxxxxxxxxxxxxxxxx, alexander. h> 7 8static pte_t 9 10 unsignedlong highstart_pfn highend_pfn 11 12 void kmap struct page page 13 14void addr 15 16 might_sleep 17if 18return page_address 19 kmap_high 20 flush_tlb_one unsignedlong 21 22return addr 23 24 EXPORT_SYMBOL Cc: Richard Weinberger <richard@xxxxxx>, Dave Hansen <dave@xxxxxxxx>, ksummit <ksummit@xxxxxxxxxxxxxxx>, linux-kernel <linux-kernel@xxxxxxxxxxxxxxx>, linux-arm-kernel <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>, linuxppc-dev <linuxppc-dev@xxxxxxxxxxxxxxxx>, linux-mips <linux-mips@xxxxxxxxxxxxxxx>, linux-mm <linux-mm@xxxxxxxxx>, imx <imx Sep 10, 2025 · To: torvalds@xxxxxxxxxxxxxxxxxxxx Subject: Re: [TECH TOPIC] Reaching consensus on CONFIG_HIGHMEM phaseout From: René Herman <rene. org/wiki/Highmem 在MIPS32 CPU中不经过MMU转换的内存窗口只有kseg0和kseg1 的512MB的大小，而且这两个内存窗口映射到同一得0~512M的物理地址空间。 On Sat, Oct 09, 2010 at 06:53:42PM -0700, Kevin Cernekee wrote: > [v3: Patch has been rebased against linux-queue. He should get [patch V3 14/37] nds32/mm/highmem: Switch to generic kmap atomic -- Linux MIPS Kernel Archive prev in list next in list prev in thread next in thread List: git-commits-head Subject: [MIPS] Enable highmem for all MIPS32 and MIPS64 processors. infradead. eu>, Richard Weinberger <richard@. herman@xxxxxxxxx> Date: Wed, 10 Sep 2025 03:06:01 +0200 Cc: Liam. - 256MB Normal - 128MB HighMem * I checked 'free' command: we have 340MB space. A. Commercial Alternative to JupyterHub. > 3. org>, <linux-mm@ck. mbksalg7odarw8wihra14aci3ekxxptt5eqgtfjdipjf0a