From mboxrd@z Thu Jan 1 00:00:00 1970 From: martin.petersen@oracle.com (Martin K. Petersen) Date: Tue, 02 Apr 2019 22:57:31 -0400 Subject: [PATCH v3 7/7] fs/ext4, jbd2: add support for passing write-hint with journal In-Reply-To: <1553846032-4451-8-git-send-email-joshi.k@samsung.com> (Kanchan Joshi's message of "Fri, 29 Mar 2019 13:23:52 +0530") References: <1553846032-4451-1-git-send-email-joshi.k@samsung.com> <1553846032-4451-8-git-send-email-joshi.k@samsung.com> Message-ID: Kanchan, > For NAND based SSDs, mixing of data with different life-time reduces > efficiency of internal garbage-collection. During FS operations, > series of journal updates will follow/precede series of data/meta > updates, causing intermixing inside SSD. By passing a write-hint with > journal, its write can be isolated from other data/meta writes, > leading to endurance/performance benefit on SSD. Why not just introduce REQ_JOURNAL and let the device driver decide how to turn that into something appropriate for the device? That's what I'll need for SCSI. Existing SCSI streams are not a good fit. -- Martin K. Petersen Oracle Linux Engineering