On Thu, May 21, 2015 at 05:28:28PM +0800, Alex Shi wrote:
Hi Greg,
It was reported this commit could save few seconds sometime in consequence writing on smart phone.
commit 7afe5aa59ed3da7b6161617e7f157c7c680dc41e ext4: convert write_begin methods to stable_page_writes semantics
The patch helps because most of storage today doesn't require that the page isn't changed while IO is in flight. That is required only for data checksumming or copy-on-write semantics but ext4 does neither of those. So we don't have to wait for IO completion in ext4_write_begin() unless underlying storage requires it.
HonzaSeems it is a very simple and useful patch for some stable kernel, like lts 3.10. Would you like to pick it up?
If Jan and Ted say it's ok, I'll queue it up.
Have you tried this patch and verified that it does fix an issue and is measurable?
thanks,
greg k-h