Date: Thu, 31 Mar 2011 22:33:39 +0000 From: Alexander Best <arundel@freebsd.org> To: freebsd-current@freebsd.org Subject: multiple issues with devstat_*(9) Message-ID: <20110331223339.GA13682@freebsd.org>
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hi there,
i think there are multiple issues with devstat. i found the following in
devicestat.h:
/*
* These types are intended to aid statistics gathering/display programs.
* The first 13 types (up to the 'target' flag) are identical numerically
* to the SCSI device type numbers. The next 3 types designate the device
* interface. Currently the choices are IDE, SCSI, and 'other'. The last
* flag specifies whether or not the given device is a passthrough device
* or not. If it is a passthrough device, the lower 4 bits specify which
* type of physical device lies under the passthrough device, and the next
* 4 bits specify the interface.
*/
typedef enum {
DEVSTAT_TYPE_DIRECT = 0x000,
DEVSTAT_TYPE_SEQUENTIAL = 0x001,
DEVSTAT_TYPE_PRINTER = 0x002,
DEVSTAT_TYPE_PROCESSOR = 0x003,
DEVSTAT_TYPE_WORM = 0x004,
DEVSTAT_TYPE_CDROM = 0x005,
DEVSTAT_TYPE_SCANNER = 0x006,
DEVSTAT_TYPE_OPTICAL = 0x007,
DEVSTAT_TYPE_CHANGER = 0x008,
DEVSTAT_TYPE_COMM = 0x009,
DEVSTAT_TYPE_ASC0 = 0x00a,
DEVSTAT_TYPE_ASC1 = 0x00b,
DEVSTAT_TYPE_STORARRAY = 0x00c,
DEVSTAT_TYPE_ENCLOSURE = 0x00d,
DEVSTAT_TYPE_FLOPPY = 0x00e,
DEVSTAT_TYPE_MASK = 0x00f,
DEVSTAT_TYPE_IF_SCSI = 0x010,
DEVSTAT_TYPE_IF_IDE = 0x020,
DEVSTAT_TYPE_IF_OTHER = 0x030,
DEVSTAT_TYPE_IF_MASK = 0x0f0,
DEVSTAT_TYPE_PASS = 0x100
} devstat_type_flags;
also the devstat(9) man page says:
Each device is given a device type. Pass-through devices have the same
underlying device type and interface as the device they provide an inter-
face for, but they also have the pass-through flag set. The base device
types are identical to the SCSI device type numbers, so with SCSI periph-
erals, the device type returned from an inquiry is usually ORed with the
SCSI interface type and the pass-through flag if appropriate. The device
type flags are as follows:
...so let's get started:
otaku% iostat -n100
tty ada0 ada1 md0 cd0 pass0 pass1 pass2 cpu
tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id
1 92 21.18 0 0.01 24.37 12 0.29 0.00 0 0.00 60.27 0 0.01 0.37 0 0.00 0.37 0 0.00 0.00 0 0.00 5 0 4 0 90
..so far so good
otaku% iostat -t da
tty ada0 ada1 md0 cpu
tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id
1 92 21.18 0 0.01 24.37 12 0.29 0.00 0 0.00 5 0 4 0 90
...not good! this should include two pass devices!
otaku% iostat -t scsi
tty cd0 cpu
tin tout KB/t tps MB/s us ni sy in id
1 92 60.27 0 0.01 5 0 4 0 90
..what?
otaku% iostat -t ide
tty cpu
tin tout us ni sy in id
1 92 5 0 4 0 90
otaku% iostat -t other
tty cpu
tin tout us ni sy in id
1 92 5 0 4 0 90
...what about md0? ada0? ada1? md0?
otaku% iostat -t cd0
tty cd0 cpu
tin tout KB/t tps MB/s us ni sy in id
1 92 60.27 0 0.01 5 0 4 0 90
...this should also include a pass device
otaku% iostat -t pass
tty pass0 pass1 pass2 cpu
tin tout KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s us ni sy in id
1 92 0.37 0 0.00 0.37 0 0.00 0.00 0 0.00 5 0 4 0 90
...this one's working as expected.
funny thing is i found the following in scsi_pass.c:
softc->device_stats = devstat_new_entry("pass",
periph->unit_number, 0,
DEVSTAT_NO_BLOCKSIZE
| (no_tags ? DEVSTAT_NO_ORDERED_TAGS : 0),
softc->pd_type |
DEVSTAT_TYPE_IF_SCSI |
DEVSTAT_TYPE_PASS,
DEVSTAT_PRIORITY_PASS);
...so pass* *should* show up under iostat -t scsi.
this is all very weird. it seems the DEVSTAT_TYPE_IF_* stuff has some major
problems. also the pass* devices aren't beeing aasigned to DEVSTAT_TYPE_DIRECT
and DEVSTAT_TYPE_CDROM, as devstat(9) suggests.
cheers.
alex
--
a13x
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