Messages in this thread |  | | Date | Fri, 25 Aug 2006 00:25:01 -0700 | | From | Stephane Eranian <> | | Subject | Re: [PATCH 9/18] 2.6.17.9 perfmon2 patch for review: kernel-level interface |
| |
Hi,
On Fri, Aug 25, 2006 at 02:56:37AM -0400, Chuck Ebbert wrote: > On Wed, 23 Aug 2006 15:54:47 -0700, Andrew Morton wrote: > > > > > Some users have requested the ability to create a monitoring session > > > > with perfmon2 from iside the kernel using a kernel thread. Perfmon2 > > > > leverages a lot of kernel mechanisms which are not easy to use for > > > > inside the kernel: e.g. file descriptor, signals, system calls. > > > > > > Again, please drop this. There are no planned intree kernel users > > > so far, and once we add them we can architect a proper API for them. > > > Getting rid of this should also help to collapse the tons of useless > > > abstractions layers in the current perfmon code. > > > > > > > Yes, I think we either need a stronger argument for including this code, or > > we drop it. > > This interface is for people writing kprobes who want to do performance > monitoring within their probe code. There will probably never be any > in-kernel users, just like there are no in-kernel users of kprobes. > That is indeed the reason why I put this in. In the context of kprobes code (callback), I don't think it is possible to make some upcall to userland to interact with the perfmon2 interface. Yet, I think that combining kprobes with monitoring could be very useful. A simple example is to use kprobes to control where monitoring starts and stops, e.g., on a function boundaries.
> > It is especially worrisome that the exports which are added here are plain > > old EXPORT_SYMBOL(). > > kprobes exports are all GPL, so these should be too. > Yes. I am just too used to EXPORT_SYMBOL(). I will fix this in the next patch.
-- -Stephane - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |