mtrace | simple c hooks around malloc/realloc/free

Change a join configuration of a paint for the polyline. You may also want to change a cap configuration (that's for ends of the polyline).

For example:

Have you tried actually calling your macro?

There is perf mem tool implemented for some modern x86/EM64T CPUs (probably, Intel-only; Ivy and newer desktop/server cpus). Man page of perf mem is http://man7.org/linux/man-pages/man1/perf-mem.1.html and same text in kernel docs dir: http://lxr.free-electrons.com/source/tools/perf/Documentation/perf-mem.txt. The text is incomplete; the best docs are sources: tools/perf/builtin-mem.c & partially in tools/perf/builtin-report.c. No details in https://perf.wiki.kernel.org/index.php/Tutorial.

Unlike qemu-mtrace it will not log every memory access, but only every Nth access where N is like 10000 or 100000. But it works with native speed and low overhead. Use perf mem record ./program to record pattern; try to add -a or -C cpulist for system-wide or global sampling for some CPU cores. There is no way to log (trace) all and every memory access from inside the system (tool should write info to memory and will log this access - this is infinite recursion with finite memory), but there are very costly proprietary system-specific external tracing solutions like JTAG or SDRAM sniffer ($5k or more).

The tools of perf mem where added around 2013 (3.10 version of linux kernel), there are several results of searching perf mem on lwn: https://lwn.net/Articles/531766/

With this patch, it is possible to sample (not trace) memory accesses (load, store). For loads, the instruction and data addresses are captured along with the latency and data source. For stores, the instruction and data addresses are capture along with limited cache and TLB information.

The current patches implement the feature on Intel processors starting with Nehalem. The patches leverage the PEBS Load Latency and Precise Store mechanisms. Precise Store is present only on Sandy Bridge and Ivy Bridge based processors.

Physical address sampling support added: https://lwn.net/Articles/555890/ (perf mem --phys-addr -t load rec); (there is also bit related 2016 year c2c perf tool "to track down cacheline contention": https://lwn.net/Articles/704125/ with examples https://joemario.github.io/blog/2016/09/01/c2c-blog/)

Some random slides on perf mem:

• http://indico.cern.ch/event/280897/contributions/1628882/attachments/515361/711133/SE-CERN_PMU_workshop_2013.pdf#page=4
• http://www.linuxtag.org/2013/fileadmin/www.linuxtag.org/slides/Arnaldo_Melo_-_Linux__perf__tools__Overview_and_Current_Developments.e323.pdf#page=10
• https://people.netfilter.org/pablo/netdev0.1/slides/sowa-perf-analytics.pdf#page=19

Some info on decoding perf mem -D report: perf mem -D report