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No more free serial devices #267

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x-o1d opened this issue Aug 4, 2016 · 0 comments
Open

No more free serial devices #267

x-o1d opened this issue Aug 4, 2016 · 0 comments

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@x-o1d
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x-o1d commented Aug 4, 2016

Kernel reports no more free serial devices for with minor numbers way below 512 for PL2303 serial tty interface.

Mainline discussion:
http://marc.info/?l=linux-usb&m=146844268111849&w=2
wens pushed a commit that referenced this issue Jun 8, 2017
@4ast @davem330
bpf: split bpf core interpreter
f696b8f 
split __bpf_prog_run() interpreter into stack allocation and execution parts.
The code section shrinks which helps interpreter performance in some cases.
   text	   data	    bss	    dec	    hex	filename
  26350	  10328	    624	  37302	   91b6	kernel/bpf/core.o.before
  25777	  10328	    624	  36729	   8f79	kernel/bpf/core.o.after

Very short programs got slower (due to extra function call):
Before:
test_bpf: #89 ALU64_ADD_K: 1 + 2 = 3 jited:0 7 PASS
test_bpf: #90 ALU64_ADD_K: 3 + 0 = 3 jited:0 8 PASS
test_bpf: #91 ALU64_ADD_K: 1 + 2147483646 = 2147483647 jited:0 7 PASS
test_bpf: #92 ALU64_ADD_K: 4294967294 + 2 = 4294967296 jited:0 11 PASS
test_bpf: #93 ALU64_ADD_K: 2147483646 + -2147483647 = -1 jited:0 7 PASS
After:
test_bpf: #89 ALU64_ADD_K: 1 + 2 = 3 jited:0 11 PASS
test_bpf: #90 ALU64_ADD_K: 3 + 0 = 3 jited:0 11 PASS
test_bpf: #91 ALU64_ADD_K: 1 + 2147483646 = 2147483647 jited:0 11 PASS
test_bpf: #92 ALU64_ADD_K: 4294967294 + 2 = 4294967296 jited:0 14 PASS
test_bpf: #93 ALU64_ADD_K: 2147483646 + -2147483647 = -1 jited:0 10 PASS

Longer programs got faster:
Before:
test_bpf: #266 BPF_MAXINSNS: Ctx heavy transformations jited:0 20286 20513 PASS
test_bpf: #267 BPF_MAXINSNS: Call heavy transformations jited:0 31853 31768 PASS
test_bpf: #268 BPF_MAXINSNS: Jump heavy test jited:0 9815 PASS
test_bpf: #269 BPF_MAXINSNS: Very long jump backwards jited:0 6 PASS
test_bpf: #270 BPF_MAXINSNS: Edge hopping nuthouse jited:0 13959 PASS
test_bpf: #271 BPF_MAXINSNS: Jump, gap, jump, ... jited:0 210 PASS
test_bpf: #272 BPF_MAXINSNS: ld_abs+get_processor_id jited:0 21724 PASS
test_bpf: #273 BPF_MAXINSNS: ld_abs+vlan_push/pop jited:0 19118 PASS
After:
test_bpf: #266 BPF_MAXINSNS: Ctx heavy transformations jited:0 19008 18827 PASS
test_bpf: #267 BPF_MAXINSNS: Call heavy transformations jited:0 29238 28450 PASS
test_bpf: #268 BPF_MAXINSNS: Jump heavy test jited:0 9485 PASS
test_bpf: #269 BPF_MAXINSNS: Very long jump backwards jited:0 12 PASS
test_bpf: #270 BPF_MAXINSNS: Edge hopping nuthouse jited:0 13257 PASS
test_bpf: #271 BPF_MAXINSNS: Jump, gap, jump, ... jited:0 213 PASS
test_bpf: #272 BPF_MAXINSNS: ld_abs+get_processor_id jited:0 19389 PASS
test_bpf: #273 BPF_MAXINSNS: ld_abs+vlan_push/pop jited:0 19583 PASS

For real world production programs the difference is noise.

This patch is first step towards reducing interpreter stack consumption.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
jwrdegoede pushed a commit to jwrdegoede/linux-sunxi that referenced this issue Oct 9, 2023
@borkmann @anakryiko
selftest/bpf: Add various selftests for program limits
d1a783d 
Add various tests to check maximum number of supported programs
being attached:

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  ./test_progs -t tc_opts
  [    1.185325] bpf_testmod: loading out-of-tree module taints kernel.
  [    1.186826] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  [    1.270123] tsc: Refined TSC clocksource calibration: 3407.988 MHz
  [    1.272428] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fc932722, max_idle_ns: 440795381586 ns
  [    1.276408] clocksource: Switched to clocksource tsc
  linux-sunxi#252     tc_opts_after:OK
  linux-sunxi#253     tc_opts_append:OK
  linux-sunxi#254     tc_opts_basic:OK
  linux-sunxi#255     tc_opts_before:OK
  linux-sunxi#256     tc_opts_chain_classic:OK
  linux-sunxi#257     tc_opts_chain_mixed:OK
  linux-sunxi#258     tc_opts_delete_empty:OK
  linux-sunxi#259     tc_opts_demixed:OK
  linux-sunxi#260     tc_opts_detach:OK
  linux-sunxi#261     tc_opts_detach_after:OK
  linux-sunxi#262     tc_opts_detach_before:OK
  linux-sunxi#263     tc_opts_dev_cleanup:OK
  linux-sunxi#264     tc_opts_invalid:OK
  linux-sunxi#265     tc_opts_max:OK              <--- (new test)
  linux-sunxi#266     tc_opts_mixed:OK
  linux-sunxi#267     tc_opts_prepend:OK
  linux-sunxi#268     tc_opts_replace:OK
  linux-sunxi#269     tc_opts_revision:OK
  Summary: 18/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230929204121.20305-2-daniel@iogearbox.net
jwrdegoede pushed a commit to jwrdegoede/linux-sunxi that referenced this issue Oct 25, 2023
@borkmann
selftests/bpf: Test bpf_mprog query API via libbpf and raw syscall
f9b0879 
Add a new test case which performs double query of the bpf_mprog through
libbpf API, but also via raw bpf(2) syscall. This is testing to gather
first the count and then in a subsequent probe the full information with
the program array without clearing passed structs in between.

  # ./vmtest.sh -- ./test_progs -t tc_opts
  [...]
  ./test_progs -t tc_opts
  [    1.398818] tsc: Refined TSC clocksource calibration: 3407.999 MHz
  [    1.400263] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fd336761, max_idle_ns: 440795243819 ns
  [    1.402734] clocksource: Switched to clocksource tsc
  [    1.426639] bpf_testmod: loading out-of-tree module taints kernel.
  [    1.428112] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  linux-sunxi#252     tc_opts_after:OK
  linux-sunxi#253     tc_opts_append:OK
  linux-sunxi#254     tc_opts_basic:OK
  linux-sunxi#255     tc_opts_before:OK
  linux-sunxi#256     tc_opts_chain_classic:OK
  linux-sunxi#257     tc_opts_chain_mixed:OK
  linux-sunxi#258     tc_opts_delete_empty:OK
  linux-sunxi#259     tc_opts_demixed:OK
  linux-sunxi#260     tc_opts_detach:OK
  linux-sunxi#261     tc_opts_detach_after:OK
  linux-sunxi#262     tc_opts_detach_before:OK
  linux-sunxi#263     tc_opts_dev_cleanup:OK
  linux-sunxi#264     tc_opts_invalid:OK
  linux-sunxi#265     tc_opts_max:OK
  linux-sunxi#266     tc_opts_mixed:OK
  linux-sunxi#267     tc_opts_prepend:OK
  linux-sunxi#268     tc_opts_query:OK            <--- (new test)
  linux-sunxi#269     tc_opts_replace:OK
  linux-sunxi#270     tc_opts_revision:OK
  Summary: 19/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20231006220655.1653-4-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
jwrdegoede pushed a commit to jwrdegoede/linux-sunxi that referenced this issue Oct 25, 2023
@borkmann
selftests/bpf: Test query on empty mprog and pass revision into attach
685446b 
Add a new test case to query on an empty bpf_mprog and pass the revision
directly into expected_revision for attachment to assert that this does
succeed.

  ./test_progs -t tc_opts
  [    1.406778] tsc: Refined TSC clocksource calibration: 3407.990 MHz
  [    1.408863] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fcaf6eb0, max_idle_ns: 440795321766 ns
  [    1.412419] clocksource: Switched to clocksource tsc
  [    1.428671] bpf_testmod: loading out-of-tree module taints kernel.
  [    1.430260] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  linux-sunxi#252     tc_opts_after:OK
  linux-sunxi#253     tc_opts_append:OK
  linux-sunxi#254     tc_opts_basic:OK
  linux-sunxi#255     tc_opts_before:OK
  linux-sunxi#256     tc_opts_chain_classic:OK
  linux-sunxi#257     tc_opts_chain_mixed:OK
  linux-sunxi#258     tc_opts_delete_empty:OK
  linux-sunxi#259     tc_opts_demixed:OK
  linux-sunxi#260     tc_opts_detach:OK
  linux-sunxi#261     tc_opts_detach_after:OK
  linux-sunxi#262     tc_opts_detach_before:OK
  linux-sunxi#263     tc_opts_dev_cleanup:OK
  linux-sunxi#264     tc_opts_invalid:OK
  linux-sunxi#265     tc_opts_max:OK
  linux-sunxi#266     tc_opts_mixed:OK
  linux-sunxi#267     tc_opts_prepend:OK
  linux-sunxi#268     tc_opts_query:OK
  linux-sunxi#269     tc_opts_query_attach:OK     <--- (new test)
  linux-sunxi#270     tc_opts_replace:OK
  linux-sunxi#271     tc_opts_revision:OK
  Summary: 20/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20231006220655.1653-6-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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