Re: where to find the kmalloc implementation

Thanks! On Thu, Jan 10, 2019 at 12:51 AM Okash Khawaja wrote: > On Wed, Jan 9, 2019 at 3:17 PM Carter Cheng wrote: > > > > Hi, > > > > I am curious where in the kernel sources would I find the kmalloc > implementation? I am curious how GFP_ATOMIC option

where to find the kmalloc implementation

Hi, I am curious where in the kernel sources would I find the kmalloc implementation? I am curious how GFP_ATOMIC option is implemented. Thanks, Carter. ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org https://lists.kernelnewbies.org/mail

which environment variables to use in KBUILD

Hi, I have been looking through KBUILD and trying to determine some things but my makefile skills are not completely up to par. I am wondering if there is a specific variable for adding cflags to object files that are incorporated into the vmlinux kernel image. I see there are three variables KBUI

which functions are used for dynamically allocating memory in the kernel?

Hello, I am curious which sets of functions return pointers for the purpose of dynamic allocating memory in the kernel? I am aware of get_free_pages family, kmalloc, vmalloc, the slab allocator and mempools are there any others? Thanks in advance, Carter.

Re: function stack frames in the kernel

Thanks for the clarification. On Mon, Nov 12, 2018 at 3:09 PM wrote: > On Mon, 12 Nov 2018 02:00:02 +0800, Carter Cheng said: > > Thanks for the reply but the link doesn't quite answer the question. I am > > wondering how the pointer is handled so that there is one

Re: function stack frames in the kernel

rtain assumptions in user space- but i am unsure how this applies to kernel space. On Mon, Nov 12, 2018 at 1:55 AM Augusto Mecking Caringi < augustocari...@gmail.com> wrote: > On Sun, Nov 11, 2018 at 6:04 PM Carter Cheng > wrote: > > I am wondering how the compiler divines which st

function stack frames in the kernel

Hello, I am wondering how the compiler divines which stack to use for function calls and placement of locals and arguments when a function call is made inside the kernel since the kernel has multiple call stacks. Are function calls handled manually inside kernel code or is there something special

Re: MMU related code

Thanks, I'll check it out. On Mon, Oct 29, 2018 at 3:45 PM Steffen Vogel wrote: > Hi Carter, > > On Mon, Oct 29, 2018 at 03:33:02PM +0800, Carter Cheng wrote: > > Is the /mm directory the correct place to look? It seems to contain > memory > > related code but fr

Re: MMU related code

Is the /mm directory the correct place to look? It seems to contain memory related code but from what little I have read it seems at a higher level building in some cases at least on kmalloc. I am just curious about a point raised by the SVA dissertation(by John Criswell). Another point he does rai

MMU related code

Hi, Where do I find the code in the kernel related to the MMU and resolving memory addresses? I am trying to understand what the implications are if code like this has bugs and the impact on the various functions that return chunks of memory for use via pointers (either as pages or kmalloc chunks)

Re: changing parameters in build

What I mean is will it nowadays compile the kernel with 4.19 or do you need to manually hack the inline asm? On Wed, Oct 17, 2018 at 9:11 PM Carter Cheng wrote: > Well I found and old post by John Criswell describing how he did his > dissertation project SVA. He didn't use LTO but ll

Re: changing parameters in build

ernal assembler is used? On Wed, Oct 17, 2018 at 9:05 PM wrote: > On Wed, 17 Oct 2018 20:02:46 +0800, Carter Cheng said: > > > The problem is I have to do something special with the clang options. I > > have to add an interprocedural link time optimization pass spitting out > >

Re: changing parameters in build

Thanks! On Wed, Oct 17, 2018 at 8:12 PM Greg KH wrote: > On Wed, Oct 17, 2018 at 08:02:46PM +0800, Carter Cheng wrote: > > The problem is I have to do something special with the clang options. I > > have to add an interprocedural link time optimization pass spitting out > &

Re: changing parameters in build

800, Carter Cheng wrote: > > Hi, > > > > I am having exploring how much work it would be to do whole kernel > > optimization using clang on the current kernel. My understanding is the > > kernel uses a recursive make file system. I am curious if there are any > > easy w

changing parameters in build

Hi, I am having exploring how much work it would be to do whole kernel optimization using clang on the current kernel. My understanding is the kernel uses a recursive make file system. I am curious if there are any easy ways to get the kernel to build llvm bit code for all files without going thro

Re: Testing the performance impact of kernel modifications

800, Carter Cheng said: > > I am actually looking at some changes that litter the kernel with short > > code snippets and thus according to papers i have read can result in CPU > > hits of around 48% when applied is userspace. > > You're going to need to be more specif

Re: Testing the performance impact of kernel modifications

ace papers measuring degradations in overall system performance when adding safety checks(perhaps redundant sometimes) into the kernel. On Tue, Oct 16, 2018 at 1:08 AM wrote: > On Mon, 15 Oct 2018 23:42:03 +0800, Carter Cheng said: > > > I was wondering what are some good ways to

Testing the performance impact of kernel modifications

Hi, I was wondering what are some good ways to assess the performance impact of kernel modifications. Are there some papers in the literature where this is done? Does one need to differentiate between CPU bound and different types of I/O bound processes etc? Regards, Carter.

Re: link time analysis for the kernel.

(bitcode) into a single file and then convert them into machine code at one go. On Fri, Oct 12, 2018 at 10:20 AM wrote: > On Thu, 11 Oct 2018 21:45:16 +0800, Carter Cheng said: > > > There are some detaills about the current procedures for linking the > kernel > > that I a

Re: link time analysis for the kernel.

sorry not a kernel loader but an ELF loader. On Fri, Oct 12, 2018 at 2:55 AM Carter Cheng wrote: > Actually I have compiled and installed kernels before. I am wondering > however if LTO still works for compiling kernel images on clang or gcc > since my understanding is the kernel code

Re: link time analysis for the kernel.

a bootloader which my understanding is cannot read ELF(is this correct?). On Fri, Oct 12, 2018 at 2:02 AM wrote: > > > 11.10.2018, 17:48, "Carter Cheng" : > > Hi, > > > > Hello, > > I want to ask pardon me and have you ever compiled a linux kernel? &

link time analysis for the kernel.

Hi, There are some detaills about the current procedures for linking the kernel that I am unfamiliar with. My understanding is that GCC and Clang both have the ability to do link time analysis and transforms on code but is it possible to write link time passes that will run on the kernel since the

Re: Learning Linux Kernel Development

Thanks a lot. On Thu, Oct 11, 2018 at 6:42 PM wrote: > > > 10.10.2018, 19:36, "Carter Cheng" : > > > -- Forwarded message ----- > From: *Carter Cheng* > Date: Wed, Oct 10, 2018 at 10:52 PM > Subject: Learning Linux Kernel Development > To:

Re: Fwd: Learning Linux Kernel Development

Thanks for the advice. I actually have those books as well and will take a look at them. On Thu, Oct 11, 2018 at 12:03 AM wrote: > On Wed, 10 Oct 2018 23:35:20 +0800, Carter Cheng said: > > 1. After finishing the book and perhaps Understanding the Linux Kernel > and > > Li

Fwd: Learning Linux Kernel Development

-- Forwarded message - From: Carter Cheng Date: Wed, Oct 10, 2018 at 10:52 PM Subject: Learning Linux Kernel Development To: Hello, I am actually kind of interested in learning linux kernel development and have been over the last few weeks going through Love's Linux K