diff options
| author | Jeff Dike <jdike@addtoit.com> | 2006-03-31 02:30:08 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-31 12:18:50 -0800 |
| commit | 02dea0875b0f9b331a65fd6097dfd6115ca4ef24 (patch) | |
| tree | 100126d72e889296a5d8d8714dd681ab041710cb /arch/um/include | |
| parent | 85b6bce3658a823aa169586fe71ffba0f12ccc71 (diff) | |
[PATCH] UML: Hotplug memory, take 2
Changes since first version
added check for MADV_REMOVE support on the host
fixed error return botch
shrunk sprintf array by one character
This adds hotplug memory support to UML. The mconsole syntax is
config mem=[+-]n[KMG]
In other words, add or subtract some number of kilobytes, megabytes, or
gigabytes.
Unplugged pages are allocated and then madvise(MADV_TRUNCATE), which is a
currently experimental madvise extension. These pages are tracked so they
can be plugged back in later if the admin decides to give them back. The
first page to be unplugged is used to keep track of about 4M of other
pages. A list_head is the first thing on this page. The rest is filled
with addresses of other unplugged pages. This first page is not madvised,
obviously.
When this page is filled, the next page is used in a similar way and linked
onto a list with the first page. Etc. This whole process reverses when
pages are plugged back in. When a tracking page no longer tracks any
unplugged pages, then it is next in line for plugging, which is done by
freeing pages back to the kernel.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/include')
| -rw-r--r-- | arch/um/include/mem_user.h | 1 | ||||
| -rw-r--r-- | arch/um/include/os.h | 2 |
2 files changed, 2 insertions, 1 deletions
diff --git a/arch/um/include/mem_user.h b/arch/um/include/mem_user.h index a1064c5823b..a54514d2cc3 100644 --- a/arch/um/include/mem_user.h +++ b/arch/um/include/mem_user.h @@ -49,7 +49,6 @@ extern int iomem_size; extern unsigned long host_task_size; extern unsigned long task_size; -extern void check_devanon(void); extern int init_mem_user(void); extern void setup_memory(void *entry); extern unsigned long find_iomem(char *driver, unsigned long *len_out); diff --git a/arch/um/include/os.h b/arch/um/include/os.h index d3d1bc6074e..5fb84e889b2 100644 --- a/arch/um/include/os.h +++ b/arch/um/include/os.h @@ -205,6 +205,8 @@ extern int os_map_memory(void *virt, int fd, unsigned long long off, extern int os_protect_memory(void *addr, unsigned long len, int r, int w, int x); extern int os_unmap_memory(void *addr, int len); +extern int os_drop_memory(void *addr, int length); +extern int can_drop_memory(void); extern void os_flush_stdout(void); /* tt.c |