Re: How best to bypass the page cache from within a kernel module?
From: William Lee Irwin III <hidden>
Date: 2003-09-17 22:44:53
On Wed, 17 Sep 2003, William Lee Irwin III wrote:
quoted
Well, you can get one from the slab allocator, though I expect there will be a followup question here...
On Wed, Sep 17, 2003 at 05:30:50PM -0400, Alan Stern wrote:
Yes :-) The slab allocator will give me a nice piece of memory, but I will still need to turn that into a valid mm_struct. I can't call alloc_mm() and friends because they're not EXPORTed.
Well, alloc_mm() doesn't really do much, so it should be easily preppable along the same lines if it absolutely has to be a module. In truth, the mm slab should be using a ctor (the vma slab too). On Wed, 17 Sep 2003, William Lee Irwin III wrote:
quoted
Hmm. Sounds like you want to grab a user address space and do userspace stuff inside there. Maybe avoid do_execve() etc. and call sys_*() for everything else outright? The question itself probably wants sys_mmap() or some such, or handle_mm_fault() depending on what you have in mind for allocation.
On Wed, Sep 17, 2003 at 05:30:50PM -0400, Alan Stern wrote:
sys_mmap() or something along those lines would be good. But I can't call it directly because 2.6 doesn't EXPORT the sys_xxx functions. Also, I'm not clear on whether mmap() lets you create an anonymous mapping -- one backed by swap space rather than a file -- that's what I would want to do.
That's a pain. It's probably easier to just compile the driver in, then. On Wed, 17 Sep 2003, William Lee Irwin III wrote:
quoted
invalidate_inode_pages().
On Wed, Sep 17, 2003 at 05:30:50PM -0400, Alan Stern wrote:
Great! I'll search through the kernel code for it.
Should be in mm/filemap.c -- wli -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>