Re: Propagating GFP_NOFS inside __vmalloc()

[David Rientjes <rientjes@google.com>]

On Wed, 17 Nov 2010, Christoph Hellwig wrote:

> As Dave mentioned XFS also needs GFP_NOFS allocations in the low-level
> vmap machinery, which is shared with vmalloc.
> 

Ok, so vm_map_ram() probably needs to be modified to allow gfp_t to be 
passed in after the pte wrappers are in place that can be used to avoid 
the hard-wired GFP_KERNEL in arch code (Ricardo is working on that, I 
believe?); once that's done, it's trivial to pass the gfp_t for xfs to 
lower-level vmalloc code to allocate the necessary vmap_block, vmap_area, 
and radix tree data structures from the slab allocator (they are all 
order-0, at least).

I think the ultimate solution will be able to allow GFP_NOFS to be passed 
into things like vm_map_ram() and __vmalloc() and then try to avoid new 
additions and fix up the callers later, if possible, for the eventual 
removal of all gfp_t formals from the vmalloc layer.

--
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/ .
Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>