Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-20 Thread Milian Wolff
On Montag, 15. Oktober 2018 22:38:53 CEST Milian Wolff wrote: > On Donnerstag, 11. Oktober 2018 20:14:43 CEST Milian Wolff wrote: > > On Donnerstag, 11. Oktober 2018 19:37:07 CEST Mark Wielaard wrote: > > > Hi, > > > > > > My apologies for not having looked deeper at this. > > > It is a bit tricky

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-18 Thread Ulf Hermann
Consider: > 0x7fac5ec0b000 to 0x7fac5ed9a000, len = 0x18f000, offset =0 > r--p/usr/lib/libstdc++.so.6.0.25 > 0x7fac5ec94000 to 0x7fac5ed8a000, len =0xf6000, offset = 0x89000 > ---p/usr/lib/libstdc++.so.6.0.25 0x7fac5ec94000 - 0x89000 = 0x7fac5ec0b000 This i

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-17 Thread Mark Wielaard
Hi Milian, On Wed, Oct 17, 2018 at 04:52:42PM +0200, Milian Wolff wrote: > On Montag, 15. Oktober 2018 23:06:07 CEST Milian Wolff wrote: > > On Montag, 15. Oktober 2018 23:04:52 CEST Mark Wielaard wrote: > > > On Mon, 2018-10-15 at 22:38 +0200, Milian Wolff wrote: > > > > here's one example of mma

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-17 Thread Milian Wolff
On Montag, 15. Oktober 2018 23:06:07 CEST Milian Wolff wrote: > On Montag, 15. Oktober 2018 23:04:52 CEST Mark Wielaard wrote: > > Hi Milian, > > > > On Mon, 2018-10-15 at 22:38 +0200, Milian Wolff wrote: > > > here's one example of mmap events recorded by perf: > > > > > > 0x7fac5ec0b000 to 0x7f

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-15 Thread Milian Wolff
On Montag, 15. Oktober 2018 23:04:52 CEST Mark Wielaard wrote: > Hi Milian, > > On Mon, 2018-10-15 at 22:38 +0200, Milian Wolff wrote: > > here's one example of mmap events recorded by perf: > > > > 0x7fac5ec0b000 to 0x7fac5ed9a000, len = 0x18f000, offset > > =0r--p/usr/

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-15 Thread Mark Wielaard
Hi Milian, On Mon, 2018-10-15 at 22:38 +0200, Milian Wolff wrote: > here's one example of mmap events recorded by perf: > > 0x7fac5ec0b000 to 0x7fac5ed9a000, len =   0x18f000, offset =0  >    > r--p/usr/lib/libstdc++.so.6.0.25 > 0x7fac5ec94000 to 0x7fac5ed8a000, len =0xf60

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-15 Thread Milian Wolff
On Donnerstag, 11. Oktober 2018 20:14:43 CEST Milian Wolff wrote: > On Donnerstag, 11. Oktober 2018 19:37:07 CEST Mark Wielaard wrote: > > Hi, > > > > My apologies for not having looked deeper at this. > > It is a bit tricky and I just didnt have enough time to > > really sit down and think it all

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-15 Thread Milian Wolff
On Donnerstag, 11. Oktober 2018 20:14:43 CEST Milian Wolff wrote: > On Donnerstag, 11. Oktober 2018 19:37:07 CEST Mark Wielaard wrote: > > Hi, > > > > My apologies for not having looked deeper at this. > > It is a bit tricky and I just didnt have enough time to > > really sit down and think it all

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-11 Thread Milian Wolff
On Donnerstag, 11. Oktober 2018 19:37:07 CEST Mark Wielaard wrote: > Hi, > > My apologies for not having looked deeper at this. > It is a bit tricky and I just didnt have enough time to > really sit down and think it all through yet. > > On Thu, Oct 11, 2018 at 05:02:18PM +, Ulf Hermann wrote

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-11 Thread Mark Wielaard
Hi, My apologies for not having looked deeper at this. It is a bit tricky and I just didnt have enough time to really sit down and think it all through yet. On Thu, Oct 11, 2018 at 05:02:18PM +, Ulf Hermann wrote: > is there any pattern in how the loader maps the ELF sections into > memory?

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-11 Thread Ulf Hermann
Hi Milian, is there any pattern in how the loader maps the ELF sections into memory? What sections does it actually map and which of those do we need for unwinding? I hope that only one of those MMAPs per ELF is actually meaningful and we can simply add that one's pgoff as an extra member to D

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-10-09 Thread Milian Wolff
On Mittwoch, 26. September 2018 16:38:43 CEST Milian Wolff wrote: > On Friday, September 21, 2018 3:07:29 PM CEST Mark Wielaard wrote: > > On Wed, 2018-09-19 at 14:24 +0200, Ulf Hermann wrote: > > > > We suspect perf to offset its recording-addresses of mmapped > > > > dsos/executables starting wit

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-09-26 Thread Milian Wolff
On Friday, September 21, 2018 3:07:29 PM CEST Mark Wielaard wrote: > On Wed, 2018-09-19 at 14:24 +0200, Ulf Hermann wrote: > > > We suspect perf to offset its recording-addresses of mmapped > > > dsos/executables starting with a specific section, such that they > > > denote > > > their pointers wit

Re: Handling pgoff in perf elf mmap/mmap2 elf info

2018-09-21 Thread Mark Wielaard
On Wed, 2018-09-19 at 14:24 +0200, Ulf Hermann wrote: > > We suspect perf to offset its recording-addresses of mmapped > > dsos/executables starting with a specific section, such that they > > denote > > their pointers with this pg_offset parameter. (e.g. skipping a > > library's > > header and set

Handling pgoff in perf elf mmap/mmap2 elf info

2018-09-19 Thread Christoph Sterz
Hi, I work on Hotspot[1] an opensource linux perf aggregator and visualizer. For this we use perfparser[2], which in turn uses libdw for unwinding. Recently, we found more and more perf trace-files to use the 'pgoff' field [3]. This happens especially on newer distros, (arch, opensuse tumbleweed)