arno/linux-insides
1
0
Fork 0
mirror of https://github.com/0xAX/linux-insides.git synced 2024-12-22 14:48:08 +00:00
Code Issues Releases Wiki Activity

Initialization: fix copy paste error

Browse Source 
replace "will have will have" with only "will have"

Signed-off-by: Radek Dostál <rd@radekdostal.com>
This commit is contained in:
Radek Dostál 2017-07-22 20:02:40 +02:00
parent 3ed1bd1b70
commit 9dafe28254
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
Initialization/linux-initialization-1.md
View File

@ -485,7 +485,7 @@ INIT_PER_CPU(gdt_page);
As we got `init_per_cpu__gdt_page` in `INIT_PER_CPU_VAR` and `INIT_PER_CPU` macro from linker script will be expanded we will get offset from the `__per_cpu_load`. After this calculations, we will have correct base address of the new GDT.
Generally per-CPU variables is a 2.6 kernel feature. You can understand what it is from its name. When we create `per-CPU` variable, each CPU will have will have its own copy of this variable. Here we creating `gdt_page` per-CPU variable. There are many advantages for variables of this type, like there are no locks, because each CPU works with its own copy of variable and etc... So every core on multiprocessor will have its own `GDT` table and every entry in the table will represent a memory segment which can be accessed from the thread which ran on the core. You can read in details about `per-CPU` variables in the [Theory/per-cpu](http://0xax.gitbooks.io/linux-insides/content/Concepts/per-cpu.html) post.
Generally per-CPU variables is a 2.6 kernel feature. You can understand what it is from its name. When we create `per-CPU` variable, each CPU will have its own copy of this variable. Here we creating `gdt_page` per-CPU variable. There are many advantages for variables of this type, like there are no locks, because each CPU works with its own copy of variable and etc... So every core on multiprocessor will have its own `GDT` table and every entry in the table will represent a memory segment which can be accessed from the thread which ran on the core. You can read in details about `per-CPU` variables in the [Theory/per-cpu](http://0xax.gitbooks.io/linux-insides/content/Concepts/per-cpu.html) post.
As we loaded new Global Descriptor Table, we reload segments as we did it every time: