-----Original Message----- From: Kai Mäkisara [mailto:kai.makisara@xxxxxxxxxxx] Sent: Wednesday, February 27, 2013 4:38 AM To: James Bottomley Cc: Seymour, Shane M; linux-scsi@xxxxxxxxxxxxxxx Subject: Re: [Patch][RFC] st: provide tape statistics via sysfs > The sysfs files in the patch export the statistics in the same way as the disk statistics are exported > (cf. linux/Documentation/iostats.txt). This would enable the tools parson iostats easily analyze > statistics also for tapes. Can I make a counter proposal that doesn't introduce any more ABI compatibility issues than already exist in sysfs? I'll create a statistics directory as James suggested and expose all of the individual statistics in their own files one value per file. I'll remove the extra field I wanted to add from the stat file and make it identical to the file provided for disk statistics and move the file down into the statistics directory under the device (with a warning in the code that this file must provide exactly the same information as the disks stat file and cannot provide more than that). To get the statistics I want to get I'll use the stat file plus one of the individual files. I'd still like to keep the file with the hint about how many tape drives there will be as a maximum. > The statistics represent the status at one time point and must be read together (within reason). > This means that splitting the values to several files is not a proper way to export the information. One file would be better than two, but two is a lot better than having to open and read all of them individually and get stats that really are an approximation. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
