On Thu, Aug 07, 2014 at 07:05:03PM +0800, Peng Tao wrote: > On Thu, Aug 7, 2014 at 3:23 PM, Christoph Hellwig <hch@xxxxxx> wrote: > > Instead of overflowing the XDR send buffer with our extent list allocate > > pages and pre-encode the layoutupdate payload into them. We optimistically > > allocate a single page use alloc_page and only switch to vmalloc when we > > have more extents outstanding. Currently there is only a single testcase > > (xfstests generic/113) which can reproduce large enough extent lists for > > this to occur. > > > depending on how badly the extents are fragmented, it might worth > starting an async layoutcommit within blocklayout client when bl_count > reaches certain limit, so that we don't send an unlimited amount of > extents in one layoutcommit. I though about this, but this only reduces the problem and we'd still need to be able to commit all extents for a data integrity operation, so we'd still need someting like the above. The other option I considered and prototyped was to send multiple on the wire layoutcommit calls from pnfs_layoutcommit_inode, but that did prove to be even more cumbersome. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
