On Tue, May 9, 2017 at 6:43 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Tue, May 09, 2017 at 06:40:28AM -1000, Chris Worley wrote: >> The documentation doesn't define anything but R, W, and S (and barriers). >> >> I'm guessing F is a FUA/flush, but why two F's? > > Pre-Flush and Fua. So one is pre-flush and the second is FUA? How do you tell which F you're looking at if just one? I'm seeing lots of both FWS and FWFSM. > >> Is M no-merge? > > Metadata. So, really no effect, just informational (this is an XFS fs doing the I/O). Any hints on when sync, flushes, or FUAs force flash to write to media? We're using NVMe drives. All these operations should be power-cut safe... I'm not sure if any force the driver/controller to commit to NAND when buffering (in power-cut safe memory) would be better for performance/lifespan. I'm guessing this isn't an easy question... any idea how to find out? Thanks, Chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
