Re: [RFC PATCH 0/6] Do not call ->writepage[s] from direct reclaim and use a_ops->writepages() where possible

Rik van Riel
2010-06-15T19:14:25Z

On 06/15/2010 12:54 PM, Christoph Hellwig wrote:
> On Tue, Jun 15, 2010 at 12:49:49PM -0400, Rik van Riel wrote:
>> This is already in a filesystem. Why does ->writepage get
>> called a second time? Shouldn't this have a gfp_mask
>> without __GFP_FS set?
>
> Why would it? GFP_NOFS is not for all filesystem code, but only for
> code where we can't re-enter the filesystem due to deadlock potential.

Why? How about because you know the stack is not big enough
to have the XFS call path on it twice? :)

Isn't the whole purpose of this patch series to prevent writepage
from being called by the VM, when invoked from a deep callstack
like xfs writepage?

That sounds a lot like simply wanting to not have GFP_FS...

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