Description of problem: Duron 700 desktop (ie not laptop) - upgraded from FC3, and before that previous versions of FC/ Red Hat - unnecessarily polls APM, wasting 0.2% of CPU all day, every day. Version-Release number of selected component (if applicable): 0.5.2-2 hald wakes up every so often (2 seconds? a bit less?) and reads the /proc/apm file _twice_ before going back to sleep. This is undesirable at best. Here's a system call trace of the behaviour. poll([{fd=5, events=POLLIN}, {fd=10, events=POLLIN}, {fd=11, events=POLLIN}, {fd=7, events=POLLIN}, {fd=13, events=POLLIN}, {fd=9, events=POLLIN|POLLPRI}, {fd=8, events=POLLIN}], 7, 1514) = 0 gettimeofday({1118929418, 873249}, NULL) = 0 open("//proc/apm", O_RDONLY|O_LARGEFILE) = 3 fstat64(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0 mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f1c000 read(3, "1.16ac 1.2 0x03 0x01 0xff 0x80 -"..., 1024) = 40 close(3) = 0 munmap(0xb7f1c000, 4096) = 0 open("//proc/apm", O_RDONLY|O_LARGEFILE) = 3 fstat64(3, {st_mode=S_IFREG|0444, st_size=0, ...}) = 0 mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7f1c000 read(3, "1.16ac 1.2 0x03 0x01 0xff 0x80 -"..., 1024) = 40 close(3) = 0 munmap(0xb7f1c000, 4096) = 0 gettimeofday({1118929419, 31308}, NULL) = 0 At least I should like to see this code changed to read /proc/apm only once for each repetition, but preferably I should like to be able to turn this off altogether. There's nothing for HAL to see in this APM structure on a desktop PC, just mindless repetition.
> There's nothing for HAL to see in this APM structure on a desktop > PC, just mindless repetition. If you're using APM, there's unfortunately no reliable way (we can't trust the DMI tables, sorry) to detect whether there is a battery or not so we have to do this. Suggest to use ACPI instead and then this won't happen. I've noted upstream (I'm upstream) to only read /proc/apm once per poll and perhaps poll less often (say every ten seconds instead of every two seconds) - that will be in the next release.