Hi, > -----Original Message----- > From: Luca Porzio (lporzio) [mailto:lpor...@micron.com] > Sent: Tuesday, October 20, 2015 4:05 PM > To: linux-f2fs-devel@lists.sourceforge.net; > linux-f2fs-devel@lists.sourceforge.net > Cc: (alexey.skida...@sandisk.com); jaeg...@kernel.org; Ulf Hansson > (ulf.hans...@linaro.org); > an...@tuxera.com; (alexey.skida...@sandisk.com); jaeg...@kernel.org; Ulf > Hansson > (ulf.hans...@linaro.org); an...@tuxera.com > Subject: [f2fs-dev] REQ_META and Reliable write in eMMC > > Hi, > > By discussing in the MELS (Mobile & Embedded Linux Storage Forum) we are > deciding whether it > is ok to remove the bonding between REQ_META and "Reliable Write" in eMMC > devices. > We already got a first positive ack from FS developers here > http://comments.gmane.org/gmane.linux.file-systems/97219 > > >This performance impact comes from the existing MMC SW driver solution where > >each IO request > marked with > >REQ_META is handled as a "Reliable Write" operation. > >Pretty much as a as a FUA write access, a "Reliable write" means that the > >data will be written > to the > >non-volatile memory. > >Due to the fact that every REQ_META is immediately bypassing the internal > >cache of eMMC device, > write > >performance is affected significantly. > > Wanted also to check for side effects on F2FS. > Please advise how critical is to send REQ_META as "Reliable Write"?
I don't think this kind 'Reliable' optimization should be done in eMMC for f2fs, since f2fs has already kept the write reliable by using WRITE_FLUSH | WRITE_FLUSH_FUA. > Can REQ_META be sent as a regular Write operation? Yes, I think so. Thanks, > > Thanks, > Luca Porzio > Micron > > ------------------------------------------------------------------------------ > _______________________________________________ > Linux-f2fs-devel mailing list > Linux-f2fs-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel ------------------------------------------------------------------------------ _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
