arno/linux-insides
1
0
Fork 0
mirror of https://github.com/0xAX/linux-insides.git synced 2025-01-18 11:41:08 +00:00
Code Issues Releases Wiki Activity

better explanation of memblock_merge_regions()

Browse Source
This commit is contained in:
Alexander Kuleshov 2016-10-18 00:23:07 +06:00
parent 4a6360eb23
commit bd573d9857
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
mm/linux-mm-1.md
View File

@ -310,7 +310,7 @@ As we update the size of the first memory region with the size of the next memor
memmove(next, next + 1, (type->cnt - (i + 2)) * sizeof(*next)); memmove(next, next + 1, (type->cnt - (i + 2)) * sizeof(*next));
``` ```
And decrease the count of the memory regions which belong to the `memblock_type`: The `memmove` here moves all regions which are located after the `next` region to the base address of the `next` region. In the end we just decrease the count of the memory regions which belong to the `memblock_type`:
```C ```C
type->cnt--; type->cnt--;
@ -329,6 +329,8 @@ After this we will get two memory regions merged into one:
+------------------------------------------------+ +------------------------------------------------+
``` ```
As we decreased counts of regions in a memblock with certain type, increased size of the `this` region and shifted all regions which are located after `next` region to its place.
That's all. This is the whole principle of the work of the `memblock_add_range` function. That's all. This is the whole principle of the work of the `memblock_add_range` function.
There is also `memblock_reserve` function which does the same as `memblock_add`, but with one difference. It stores `memblock_type.reserved` in the memblock instead of `memblock_type.memory`. There is also `memblock_reserve` function which does the same as `memblock_add`, but with one difference. It stores `memblock_type.reserved` in the memblock instead of `memblock_type.memory`.