Closed Bug 674986 Opened 14 years ago Closed 12 years ago

Build profiler for android devices

Categories

(Core :: General, defect)

Product:
Core
Component:
General
Version:
Other Branch
Platform:
ARM
MeeGo
Type:
defect
Priority:
Not set
Severity:
normal

Tracking

()

Status:
RESOLVED DUPLICATE of bug 831611

People

(Reporter: cjones, Unassigned)

References

Details

(Whiteboard: mobilestartupshrink)

Attachments

(1 file)

Very hacky heuristic backtrace for oprofile
3.31 KB, patch
Details | Diff | Splinter Review
jchen got oprofile working for the MSM7230 (G2) on cyanogenmod7: https://wiki.mozilla.org/Mobile/Fennec/Android/Profiling. cjones has oprofile almost working with a Hummingbird S5PC110 (Nexus S) on top of a userspace with -fno-omit-frame-pointer (i.e. should get callgraphs). It would be interesting to investigate the perf tool, since that's going to be our most reliable option moving forward. Looks like some significant build hackery is needed to cross-compile it in the kernel source though.
samples % image name app name symbol name ------------------------------------------------------------------------------- 1646 5.6573 libxul.so libxul.so pixman_composite_src_0565_0565_asm_neon 1646 100.000 libxul.so libxul.so pixman_composite_src_0565_0565_asm_neon [self] ------------------------------------------------------------------------------- 1408 4.8393 libc.so libc.so memcpy 1408 100.000 libc.so libc.so memcpy [self] ------------------------------------------------------------------------------- 635 2.1825 oprofiled oprofiled odb_update_node_with_offset 635 100.000 oprofiled oprofiled odb_update_node_with_offset [self] ------------------------------------------------------------------------------- 1 25.0000 vmlinux vmlinux vma_adjust 1 25.0000 vmlinux vmlinux split_vma 2 50.0000 vmlinux vmlinux __split_vma 482 1.6566 vmlinux vmlinux ring_buffer_consume 482 50.0000 vmlinux vmlinux ring_buffer_consume [self] 428 44.3983 vmlinux vmlinux __run_hrtimer 41 4.2531 vmlinux vmlinux enqueue_hrtimer 7 0.7261 vmlinux vmlinux hrtimer_run_queues 6 0.6224 vmlinux vmlinux hrtimer_cancel ------------------------------------------------------------------------------- 373 1.2820 vmlinux vmlinux __do_softirq 373 42.0045 vmlinux vmlinux v6_copy_user_highpage_nonaliasing 373 42.0045 vmlinux vmlinux __do_softirq [self] 49 5.5180 vmlinux vmlinux s3c_config_cdma_wimax_sleep_gpio 46 5.1802 vmlinux vmlinux do_alignment_ldmstm 36 4.0541 vmlinux vmlinux thread_group_cputime ------------------------------------------------------------------------------- 329 1.1308 libxul.so libxul.so pixman_composite_over_8888_0565_asm_neon 329 100.000 libxul.so libxul.so pixman_composite_over_8888_0565_asm_neon [self] ------------------------------------------------------------------------------- 299 1.0277 vmlinux vmlinux schedule 299 49.5033 vmlinux vmlinux schedule [self] 280 46.3576 vmlinux vmlinux l2cap_conn_start 19 3.1457 vmlinux vmlinux l2cap_security_cfm 4 0.6623 vmlinux vmlinux add_wait_queue_exclusive ------------------------------------------------------------------------------- 286 0.9830 libm.so libm.so floor 286 100.000 libm.so libm.so floor [self] ------------------------------------------------------------------------------- 272 0.9349 anon (tgid:468 range:0x45ba9000-0x45bd9000) app_process anon (tgid:468 range:0x45ba9000-0x45bd9000) 272 100.000 anon (tgid:468 range:0x45ba9000-0x45bd9000) app_process anon (tgid:468 range:0x45ba9000-0x45bd9000) [self] ------------------------------------------------------------------------------- 271 0.9314 libxul.so libxul.so _cairo_spline_decompose_into 271 100.000 libxul.so libxul.so _cairo_spline_decompose_into [self] ------------------------------------------------------------------------------- 259 0.8902 libxul.so libxul.so nsRect::ScaleToNearestPixels(float, float, int) const 259 100.000 libxul.so libxul.so nsRect::ScaleToNearestPixels(float, float, int) const [self]
Oops, fatfingered enter. Meant to say, Here's some oprofile pr0n. I have the frame pointers I need to get a callgraph, and I'm telling oprofile to collect backtraces, but something is being lost in translation somewhere. I wonder if we have to force thumb off to get reliable backtraces. That's OK, but not so great since it will skew results even more.
Whiteboard: mobilestartupshrink
(In reply to comment #2) > Oops, fatfingered enter. Meant to say, > > Here's some oprofile pr0n. I have the frame pointers I need to get a > callgraph, and I'm telling oprofile to collect backtraces, but something is > being lost in translation somewhere. > > I wonder if we have to force thumb off to get reliable backtraces. That's > OK, but not so great since it will skew results even more. Yeah, currently oprofile backtrace only supports arm mode frame pointers (using fp register), and not thumb mode frame pointers (using r7 register). It should be trivial to add thumb support. However, gcc 4.4.3 (NDKr5) generates wrong frame pointers in thumb mode anyways, so oprofile support alone is not enough for thumb support. Basically, in thumb mode, gcc always sets the frame pointer to the stack pointer, which defeats the purpose of having a frame pointer.
(In reply to comment #3) > (In reply to comment #2) > > Oops, fatfingered enter. Meant to say, > > > > Here's some oprofile pr0n. I have the frame pointers I need to get a > > callgraph, and I'm telling oprofile to collect backtraces, but something is > > being lost in translation somewhere. > > > > I wonder if we have to force thumb off to get reliable backtraces. That's > > OK, but not so great since it will skew results even more. > > Yeah, currently oprofile backtrace only supports arm mode frame pointers > (using fp register), and not thumb mode frame pointers (using r7 register). > It should be trivial to add thumb support. I built my entire userspace and firefox without thumb support and still didn't get callgraphs. I think there might be some other bug. Going to push what I have later today. "Real" thumb support doesn't sound trivial to me at all, but if you have an implementation in mind more power to you :). We could fall back on heuristics like if r11 doesn't point at a valid address, try r7 (or vice versa), but that's not strictly correct.
(In reply to comment #4) > I built my entire userspace and firefox without thumb support Ah-ha: I checked this assumption by commenting out the thumb options instead of disabling them with build flags, and got a linker error. So looks like I wasn't turning off thumb after all.
(In reply to comment #4) > I built my entire userspace and firefox without thumb support and still > didn't get callgraphs. I think there might be some other bug. Going to > push what I have later today. > > "Real" thumb support doesn't sound trivial to me at all, but if you have an > implementation in mind more power to you :). We could fall back on > heuristics like if r11 doesn't point at a valid address, try r7 (or vice > versa), but that's not strictly correct. My way would be to detect thumb mode or arm mode based on cpsr and return addresses, and choose fp or r7 based on the detected mode. FWIW, here's a patch I wrote based on an even hackier algorithm. It scans the stack and looks for likely return addresses (valid and executable memory region, branch instruction before return address, etc.) It helped me getting the oprofile backtrace in bug 658074.
Rebuilt userspace with thumb commented out, but no luck; still no callgraphs. Definitely worth investigating. Jim's patch is giving me results though. Thanks! We should probably look into cleaning it up and getting it merged into linux mainline.
Some work pwalton did on an Android profiler: https://github.com/pcwalton/piranha
OS: Android → MeeGo
Version: Trunk → Other Branch
Status: NEW → RESOLVED
Closed: 12 years ago
Resolution: --- → DUPLICATE
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