On Thu, Mar 08, 2012 at 04:41:48PM -0500, Ted Ts'o wrote: > On Thu, Mar 08, 2012 at 04:38:08PM -0500, Chris Mason wrote: > > Btrfs currently does this, and the DIF code is by definition right > > before the write. The pages really only get set writeback when they are > > being sent in flight, so the waiting being done by the stable pages > > patch is file_write or page_mkwrite being polite and waiting for the IO > > to finish before changing the page. > > Right before submission to the bio layer? Or right before the device > driver sends the request to the host bus adapter? I was thinking of > the latter.... blktrace can probably give us numbers for how big that wait is, but hopefully it is very small. If it is too big, you can always bump nr_requests. Btrfs crcs before submit_bio, not sure when the dif code does it. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
