Re: Memory leaks

[Uday S Reddy]

On 3/3/2011 11:40 PM, Andreas Schwab wrote:

> How do you know that there is some leak?

First there was a suspicion, and now I have been running experiments.

Here are the profiles returned by (garbage-collect), pretty-printed, for 
the same Emacs session over time.  In each case, the Emacs session was 
essentially empty, with just a few stray text buffers .  The difference 
is only in what happened in between.

Initial:

(:conses (102590 . 13880)
 :syms (20328 . 54)
 :miscs (830 . 152)
 :chars 570345 :vector 329747 :floats (72 . 111)
 :intervals (348 . 189)
 :strings (21259 . 5705))

After one visit to my INBOX folder (22MB) and quitting:

(:conses (663630 . 605600)
 :syms (32257 . 2608)
 :miscs (15443 . 18022)
 :chars 1639236 :vector 454670 :floats (345 . 261)
 :intervals (503 . 622)
 :strings (99122 . 90256))

After a second visit to the same folder and quitting:

(:conses (1113362 . 334402)
 :syms (32264 . 2807)
 :miscs (15467 . 36265)
 :chars 1833568 :vector 456351 :floats (345 . 328)
 :intervals (604 . 849)
 :strings (138140 . 122806))

After several hours of usage:

(:conses (1558351 . 313757)
 :syms (93011 . 347)
 :miscs (140492 . 28025)
 :chars 9264181 :vector 2283330 :floats (347 . 638)
 :intervals (2771 . 4880)
 :strings (467731 . 34316))

At this point, the total memory occupied was about 400MB, and Emacs 
complained that "memory was exhausted; save buffers and quit" (or 
something to that effect).  I ran garbage-collect, killed all the stray 
buffers and left it around for a while (about 10-15 minutes), and the 
memory came down to 340MB.  (The memory usage figures are from the 
Windows XP Task Manger - "VM Size" - VM here referring to the virtual 
memory.)

After that, I could do a couple of more folder visits and then Emacs 
crashed in the middle of a folder visit.  Come to think of it, almost 
all the Emacs crashes I have experienced over the last year or so were 
probably related to the memory leak problem.  They all happened when I 
was visiting a folder.

Recalling from my memory, these kind of crashes have started happening 
with Emacs 22.3.  There were no such crashes before then.  I stuck to 
Emacs 22.2 for a long time, hoping that whatever was causing the crashes 
would get fixed in due course.  But with every new release, the same 
kind of crashes appeared.

Here is a crash report from yesterday produced by DrMinGW. 
Unfortunately, I was in the middle of a Lisp debugger session and the 
crash happened while the debugger was trying print a large data 
structure.  But this does look like a memory problem to my untrained eye.

Cheers,
Uday


---------------


emacs.exe caused an Access Violation at location 77c47412 in module 
msvcrt.dll Writing to location 18874000.

Registers:
eax=00829240 ebx=02bb2802 ecx=00000000 edx=00000001 esi=008292bf 
edi=18874000
eip=77c47412 esp=00829290 ebp=00829298 iopl=0         nv up ei ng nz ac 
pe cy
cs=001b  ss=0023  ds=0023  es=0023  fs=003b  gs=0000 
efl=00000293

Call stack:
77C47412  msvcrt.dll:77C47412  memmove
0110AD0F  emacs.exe:0110AD0F  printchar  print.c:323

0110FC03  emacs.exe:0110FC03  print_object  print.c:1645

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0111148E  emacs.exe:0111148E  print_object  print.c:2215

0111148E  emacs.exe:0111148E  print_object  print.c:2215

011105A3  emacs.exe:011105A3  print_object  print.c:1921

0110EAE2  emacs.exe:0110EAE2  print  print.c:1305

0110CF92  emacs.exe:0110CF92  Fprin1  print.c:751

01022B04  emacs.exe:01022B04  Ffuncall  eval.c:3034

01114C11  emacs.exe:01114C11  Fbyte_code  bytecode.c:680

010232C3  emacs.exe:010232C3  funcall_lambda  eval.c:3220

01022D03  emacs.exe:01022D03  Ffuncall  eval.c:3077

01114C11  emacs.exe:01114C11  Fbyte_code  bytecode.c:680

01021B46  emacs.exe:01021B46  Feval  eval.c:2356

0101ED68  emacs.exe:0101ED68  Fprogn  eval.c:415

01102A41  emacs.exe:01102A41  Fsave_window_excursion  window.c:6575

0111579A  emacs.exe:0111579A  Fbyte_code  bytecode.c:841

010232C3  emacs.exe:010232C3  funcall_lambda  eval.c:3220

01022D03  emacs.exe:01022D03  Ffuncall  eval.c:3077

010221D6  emacs.exe:010221D6  Fapply  eval.c:2506

010225FD  emacs.exe:010225FD  apply1  eval.c:2780

0101EB72  emacs.exe:0101EB72  call_debugger  eval.c:272

01022E12  emacs.exe:01022E12  Ffuncall  eval.c:3102

01114C11  emacs.exe:01114C11  Fbyte_code  bytecode.c:680

01021B46  emacs.exe:01021B46  Feval  eval.c:2356

01020165  emacs.exe:01020165  internal_catch  eval.c:1228

0111580E  emacs.exe:0111580E  Fbyte_code  bytecode.c:855

010232C3  emacs.exe:010232C3  funcall_lambda  eval.c:3220

01022D03  emacs.exe:01022D03  Ffuncall  eval.c:3077

010221D6  emacs.exe:010221D6  Fapply  eval.c:2506

010225FD  emacs.exe:010225FD  apply1  eval.c:2780

01117B84  emacs.exe:01117B84  Fcall_interactively  callint.c:396

01022B2E  emacs.exe:01022B2E  Ffuncall  eval.c:3037

010226CC  emacs.exe:010226CC  call3  eval.c:2857

01014D52  emacs.exe:01014D52  Fcommand_execute  keyboard.c:10562

010150C3  emacs.exe:010150C3  Fexecute_extended_command  keyboard.c:10675

01022AE3  emacs.exe:01022AE3  Ffuncall  eval.c:3031

0111932A  emacs.exe:0111932A  Fcall_interactively  callint.c:869

01022B2E  emacs.exe:01022B2E  Ffuncall  eval.c:3037

010226CC  emacs.exe:010226CC  call3  eval.c:2857

01014D52  emacs.exe:01014D52  Fcommand_execute  keyboard.c:10562

010076E0  emacs.exe:010076E0  command_loop_1  keyboard.c:1914

01020614  emacs.exe:01020614  internal_condition_case  eval.c:1492

01005FE3  emacs.exe:01005FE3  command_loop_2  keyboard.c:1362

01020165  emacs.exe:01020165  internal_catch  eval.c:1228

01005F9C  emacs.exe:01005F9C  command_loop  keyboard.c:1342

0100588E  emacs.exe:0100588E  recursive_edit_1  keyboard.c:956

010059F7  emacs.exe:010059F7  Frecursive_edit  keyboard.c:1019

010028F5  emacs.exe:010028F5  main  emacs.c:1835

010010DB  emacs.exe:010010DB
01001178  emacs.exe:01001178
010036D0  emacs.exe:010036D0  _start  unexw32.c:131

7C817077  kernel32.dll:7C817077  RegisterWaitForInputIdle