Hi, >> Notes/Known Issues/Limitations: >> FreeBSD can't use transfer length > 64KB. > > Since 8.0 FreeBSD can use any transfer lengths. 64K is a safety limit > for CAM SIMs that do not report maximum transfer size. If your driver > supports bigger transactions (and even if not), you should fill maxio > field in XPT_PATH_INQ response. I set maxio=1024*1024 in version 0.2.2. As a result, the request (each ccb) have 256 blocks (128KB). I don't know why it is 128KB. >> It seems CAM tag is used only 2 of 64 tags. >> I don't know a reason, but MAXPHYS limit? > > How many concurrent requests you are submitting? If you are testing it > with sequential read from file system - make sure you have sysctl > vfs.read_max set high enough. MAXPHYS does not affects number of > concurrent requests, only size of each one. I used vfs.read_max=32 and run only one dd. Now vfs.read_max=2048. I tried to run dd 4 times at background, then I got 4 x 30MB/s (read) and 4 x 21MB/s (write). Write is still slower than read, but it is enough. I can see 1 or 2 tags when reading, around 10 tags when writing. I guess that reading tag exists only for a short time. (or my execution order is not good) Thank you. Daisuke AoyamaReceived on Sun Jul 04 2010 - 09:20:47 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:40:05 UTC