Hello Robert, when do you have a chance do look at my patches? Looking forward to a positive reply. Heinz On Fri, 2011-01-21 at 11:06 +0100, Heinz Graalfs wrote: > Hello Robert, > > I'm resending yesterday's mail because I missed to specify the correct sender information. > > This is a re-posting of the patch series originally posted last month: > > http://marc.info/?l=linux-s390&m=129285043619973&w=2 > > Heinz > > Changes in > > v2: > - kernel module hwsampler removed, everything is now in oprofile kernel module > - functions from hwsampler-main.c and smpctl.c merged into arch/s390/oprofile/hwsampler.c > - functions made static > - arch/s390/include/asm/hwsampler.h moved to arch/s390/oprofile/hwsampler.h > - structs have now hws_ prefix > - config variables changed, HAVE_HWSAMPLER used only > - original patch 4 (handle_munmap.patch) removed > > Description: > > So far, OProfile takes samples by using a software interrupt. > The purpose of this series of patches is to add support for System z hardware sampling to OProfile. > > Hardware (HW) sampling is a feature provided by System z processors (z10 and follow ons). > When sampling, the processor takes samples containing the instruction address, PID, and other information. > The samples are taken at a programmable rate and stored into a buffer provided by the operating system. > The sampling process is implemented in hardware and millicode and thus does not affect the operating system > being oberved, apart from requiring buffer memory that the Linux kernel must provide. > > Hardware sampling is available in LPAR mode on 64 BIT processors only. > > The overall approach is to replace the software-based sample generation by hardware sampling. > All required functionality to control the HW sampling mechanism is added to the oprofile kernel module. > The functions provide support for > - controlling the sampling hardware, > - setting up appropriate buffer structures (HW buffers), > - retrieving sample entries from these buffers. > Multiple CPUs can be handled. > > The samples contain the instruction address, a bit distinguishing between kernel and user space, > and for user space samples also the PID. > Instead of taking samples from its own per-CPU buffers, OProfile would rather take samples from the > HW buffers. > > When hardware sampling can be enabled on the current System z processor it will be the new default. > Switching back to timer based sampling can be established by using > > echo 0 > /dev/oprofile/hwsampling/hwsampler > > The user space drivers of OProfile also need an extension to control hw sampling by appropriate options. > > > ------------------------------------------------------------------------------ > Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)! > Finally, a world-class log management solution at an even better price-free! > Download using promo code Free_Logger_4_Dev2Dev. Offer expires > February 28th, so secure your free ArcSight Logger TODAY! > http://p.sf.net/sfu/arcsight-sfd2d > _______________________________________________ > oprofile-list mailing list > oprofile-list@xxxxxxxxxxxxxxxxxxxxx > https://lists.sourceforge.net/lists/listinfo/oprofile-list -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
