RELAY_MMAP_BUF(9) relay interface support RELAY_MMAP_BUF(9)NAME
relay_mmap_buf - mmap channel buffer to process address space
SYNOPSIS
int relay_mmap_buf(struct rchan_buf * buf, struct vm_area_struct * vma);
ARGUMENTS
buf
relay channel buffer
vma
vm_area_struct describing memory to be mapped
DESCRIPTION
Returns 0 if ok, negative on error
Caller should already have grabbed mmap_sem.
COPYRIGHT Kernel Hackers Manual 2.6. July 2010 RELAY_MMAP_BUF(9)
Check Out this Related Man Page
__GET_USER_PAGES(9) Memory Management in Linux __GET_USER_PAGES(9)NAME
__get_user_pages - pin user pages in memory
SYNOPSIS
long __get_user_pages(struct task_struct * tsk, struct mm_struct * mm, unsigned long start, unsigned long nr_pages, unsigned int gup_flags,
struct page ** pages, struct vm_area_struct ** vmas, int * nonblocking);
ARGUMENTS
tsk
task_struct of target task
mm
mm_struct of target mm
start
starting user address
nr_pages
number of pages from start to pin
gup_flags
flags modifying pin behaviour
pages
array that receives pointers to the pages pinned. Should be at least nr_pages long. Or NULL, if caller only intends to ensure the pages
are faulted in.
vmas
array of pointers to vmas corresponding to each page. Or NULL if the caller does not require them.
nonblocking
whether waiting for disk IO or mmap_sem contention
DESCRIPTION
Returns number of pages pinned. This may be fewer than the number requested. If nr_pages is 0 or negative, returns 0. If no pages were
pinned, returns -errno. Each page returned must be released with a put_page call when it is finished with. vmas will only remain valid
while mmap_sem is held.
Must be called with mmap_sem held for read or write.
__get_user_pages walks a process's page tables and takes a reference to each struct page that each user address corresponds to at a given
instant. That is, it takes the page that would be accessed if a user thread accesses the given user virtual address at that instant.
This does not guarantee that the page exists in the user mappings when __get_user_pages returns, and there may even be a completely
different page there in some cases (eg. if mmapped pagecache has been invalidated and subsequently re faulted). However it does guarantee
that the page won't be freed completely. And mostly callers simply care that the page contains data that was valid *at some point in time*.
Typically, an IO or similar operation cannot guarantee anything stronger anyway because locks can't be held over the syscall boundary.
If gup_flags & FOLL_WRITE == 0, the page must not be written to. If the page is written to, set_page_dirty (or set_page_dirty_lock, as
appropriate) must be called after the page is finished with, and before put_page is called.
If nonblocking != NULL, __get_user_pages will not wait for disk IO or mmap_sem contention, and if waiting is needed to pin all pages,
*nonblocking will be set to 0.
In most cases, get_user_pages or get_user_pages_fast should be used instead of __get_user_pages. __get_user_pages should be used only if
you need some special gup_flags.
COPYRIGHT Kernel Hackers Manual 3.10 June 2014 __GET_USER_PAGES(9)
Hi all,
I want to create a new user and grant him ONLY transfer files access to a specific directory where he can only upload and read the files. He should be restricted to this activity only.
Regards (6 Replies)
Hi everyone,
I know the following questions are noobish questions but I am asking them because I am confused about the basics of history behind UNIX and LINUX.
Ok onto business, my questions are-:
Was/Is UNIX ever an open source operating system ?
If UNIX was... (21 Replies)
Hi,
Last 2 weeks I have searched many forums and i haven't found the answer for the question:
How to get all command output to Putty title?
Needed it for other programs to know when some jobs on a server is done and is it done right or wrong. Plink stdout and stdin wasn't working, i used many... (1 Reply)
anyone have any idea how do to this with auth_attr?
I suspect if I grant him
solaris.device.:RO::Device Allocation::help=DevAllocHeader.html
that will work but I'm unsure. Just looking for a second opinion. (10 Replies)
I am looking for a stable, reliable system to replace my current Windows systems in the home. These are simple systems that I purchased from the local Big Box store.
I have heard many good things about Unix and it's various children and it sounds like a good option to me. I have worked... (2 Replies)
We have a lot of scripts using cut as :
cut -c 0-8 --works for cut (GNU coreutils) 5.97, but does not work for cut (GNU coreutils) 8.4.
Gives error -
cut: fields and positions are numbered from 1
Try `cut --help' for more information.
The position needs to start with 1 for later... (6 Replies)
I've got a problem with a proxy configuration. We have an LDAP group that lists all users who are authorised to use the proxy to FTP (usually Filezilla) out to the world, and by implication those not in the group should be denied. My users are delighted that this has been enabled and those that... (9 Replies)
hi folks,
how to using tar with exclude directory and compress it using tar.Z
i only know how to exclude dir only with this command below:
tar -cvf /varios/restore/test.tar -X excludefile.txt /jfma/test1/
how to compress it using 1 command?
Thanx
Please use CODE tags as... (6 Replies)
Hello All,
I had recently learnt a bit of Docker(which provides containerization process).
Here are some of my learning points from it.
Let us start first with very basic question:
What is Docker:
Docker is a platform for sysadmins and developers to DEPLOY, DEVELOP and RUN applications ... (7 Replies)
What is the point of this? Whenever I close my shell it appends to the history file without adding this. I have never seen it overwrite my history file.
# When the shell exits, append to the history file instead of overwriting it
shopt -s histappend (3 Replies)
Hello for all,
I am testing the behavior of a 32 bit application running on Solaris 5.10 (SPARC), and realize it reaches 4GB of memory and then crashes.
It doesn't matter the amount of used memory as application is intended to perform many transactions; rather, what I want to achieve is to... (2 Replies)