Revision 9b4fe5fb0bdd8f31f24cbfe77e38ec8155c250c5 authored by Neil Horman on 12 July 2013, 17:35:33 UTC, committed by David S. Miller on 12 July 2013, 23:28:02 UTC
this bug: https://bugzilla.redhat.com/show_bug.cgi?id=951695 Reported a dma debug backtrace: WARNING: at lib/dma-debug.c:937 check_unmap+0x47d/0x930() Hardware name: To Be Filled By O.E.M. via-rhine 0000:00:12.0: DMA-API: device driver failed to check map error[device address=0x0000000075a837b2] [size=90 bytes] [mapped as single] Modules linked in: ip6_tables gspca_spca561 gspca_main videodev media snd_hda_codec_realtek snd_hda_intel i2c_viapro snd_hda_codec snd_hwdep snd_seq ppdev mperf via_rhine coretemp snd_pcm mii microcode snd_page_alloc snd_timer snd_mpu401 snd_mpu401_uart snd_rawmidi snd_seq_device snd soundcore parport_pc parport shpchp ata_generic pata_acpi radeon i2c_algo_bit drm_kms_helper ttm drm pata_via sata_via i2c_core uinput Pid: 295, comm: systemd-journal Not tainted 3.9.0-0.rc6.git2.1.fc20.x86_64 #1 Call Trace: <IRQ> [<ffffffff81068dd0>] warn_slowpath_common+0x70/0xa0 [<ffffffff81068e4c>] warn_slowpath_fmt+0x4c/0x50 [<ffffffff8137ec6d>] check_unmap+0x47d/0x930 [<ffffffff810ace9f>] ? local_clock+0x5f/0x70 [<ffffffff8137f17f>] debug_dma_unmap_page+0x5f/0x70 [<ffffffffa0225edc>] ? rhine_ack_events.isra.14+0x3c/0x50 [via_rhine] [<ffffffffa02275f8>] rhine_napipoll+0x1d8/0xd80 [via_rhine] [<ffffffff815d3d51>] ? net_rx_action+0xa1/0x380 [<ffffffff815d3e22>] net_rx_action+0x172/0x380 [<ffffffff8107345f>] __do_softirq+0xff/0x400 [<ffffffff81073925>] irq_exit+0xb5/0xc0 [<ffffffff81724cd6>] do_IRQ+0x56/0xc0 [<ffffffff81719ff2>] common_interrupt+0x72/0x72 <EOI> [<ffffffff8170ff57>] ? __slab_alloc+0x4c2/0x526 [<ffffffff811992e0>] ? mmap_region+0x2b0/0x5a0 [<ffffffff810d5807>] ? __lock_is_held+0x57/0x80 [<ffffffff811992e0>] ? mmap_region+0x2b0/0x5a0 [<ffffffff811bf1bf>] kmem_cache_alloc+0x2df/0x360 [<ffffffff811992e0>] mmap_region+0x2b0/0x5a0 [<ffffffff811998e6>] do_mmap_pgoff+0x316/0x3d0 [<ffffffff81183ca0>] vm_mmap_pgoff+0x90/0xc0 [<ffffffff81197d6c>] sys_mmap_pgoff+0x4c/0x190 [<ffffffff81367d7e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff8101eb42>] sys_mmap+0x22/0x30 [<ffffffff81722fd9>] system_call_fastpath+0x16/0x1b Usual problem with the usual fix, add the appropriate calls to dma_mapping_error where appropriate Untested, as I don't have hardware, but its pretty straightforward Signed-off-by: Neil Horman <nhorman@tuxdriver.com> CC: David S. Miller <davem@davemloft.net> CC: Roger Luethi <rl@hellgate.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
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basic_profiling.txt
These instructions are deliberately very basic. If you want something clever,
go read the real docs ;-) Please don't add more stuff, but feel free to
correct my mistakes ;-) (mbligh@aracnet.com)
Thanks to John Levon, Dave Hansen, et al. for help writing this.
<test> is the thing you're trying to measure.
Make sure you have the correct System.map / vmlinux referenced!
It is probably easiest to use "make install" for linux and hack
/sbin/installkernel to copy vmlinux to /boot, in addition to vmlinuz,
config, System.map, which are usually installed by default.
Readprofile
-----------
A recent readprofile command is needed for 2.6, such as found in util-linux
2.12a, which can be downloaded from:
http://www.kernel.org/pub/linux/utils/util-linux/
Most distributions will ship it already.
Add "profile=2" to the kernel command line.
clear readprofile -r
<test>
dump output readprofile -m /boot/System.map > captured_profile
Oprofile
--------
Get the source (see Changes for required version) from
http://oprofile.sourceforge.net/ and add "idle=poll" to the kernel command
line.
Configure with CONFIG_PROFILING=y and CONFIG_OPROFILE=y & reboot on new kernel
./configure --with-kernel-support
make install
For superior results, be sure to enable the local APIC. If opreport sees
a 0Hz CPU, APIC was not on. Be aware that idle=poll may mean a performance
penalty.
One time setup:
opcontrol --setup --vmlinux=/boot/vmlinux
clear opcontrol --reset
start opcontrol --start
<test>
stop opcontrol --stop
dump output opreport > output_file
To only report on the kernel, run opreport -l /boot/vmlinux > output_file
A reset is needed to clear old statistics, which survive a reboot.
Computing file changes ...
