This is the mail archive of the systemtap@sourceware.org mailing list for the systemtap project.
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |
Other format: | [Raw text] |
On Wed, 2007-08-29 at 07:56 -0700, Dave Nomura wrote:So, would it be infeasible to have an interface that would allow you to do a locking write to a particular relay channel even while in bulk mode, or is this something that is determined when the channel is set up? i.e. if you did this then EVERY write would have to be locking write?
How does systemtap separate the relay channel output on a per-cpu basis? Does it just use the currently active CPU that is making the write request and put its output in the relay buffer for that CPU?Yes, in bulk mode. In stream mode there is only one channel.
Is there any way to write to a CPU specific relay buffer?In bulk mode, no. That would require locking and slow down relayfs a bit. This is what stream mode does.
So you are suggesting that I insert the CPU number at the beginning of every record and then write a program to split it apart by CPU?I think I will need this to write header information for each CPU but there would only be one active CPU that is doing all of these writes.So just use normal (stream) mode and print the cpu and maybe timestamp.
Martin
-- Dave Nomura LTC Linux Power Toolchain
Index Nav: | [Date Index] [Subject Index] [Author Index] [Thread Index] | |
---|---|---|
Message Nav: | [Date Prev] [Date Next] | [Thread Prev] [Thread Next] |