Kernel page fault with the following non-sleepable locks held:
exclusive rw vm object (vm object) r = 0 (0xfffff80004837b58) locked @ x86/iommu/intel_idpgtbl.c:550
exclusive sleep mutex AHCI channel lock (AHCI channel lock) r = 0 (0xfffffe003ce28400) locked @ kern/kern_mutex.c:211
stack backtrace:
#0 0xffffffff80c85445 at witness_debugger+0x65
#1 0xffffffff80c8659a at witness_warn+0x3ea
#2 0xffffffff810fcce6 at trap_pfault+0x86
#3 0xffffffff810cdc18 at calltrap+0x8
#4 0xffffffff81078e7e at iommu_gas_map+0x15e
#5 0xffffffff81077339 at iommu_bus_dmamap_load_something+0x119
#6 0xffffffff81076995 at iommu_bus_dmamap_load_buffer+0x1c5
#7 0xffffffff80c55a3e at _bus_dmamap_load_ccb+0x20e
#8 0xffffffff80c557cc at bus_dmamap_load_ccb+0x8c
#9 0xffffffff803929d9 at xpt_run_devq+0x2f9
#10 0xffffffff80395de7 at xpt_release_simq+0x67
#11 0xffffffff80c3027a at softclock_call_cc+0x15a
#12 0xffffffff80c31b96 at softclock_thread+0xc6
#13 0xffffffff80bc9850 at fork_exit+0x80
#14 0xffffffff810cec8e at fork_trampoline+0xe

https://people.freebsd.org/~pho/stress/log/log0317.txt

May 18 2022, 8:47 PM

pho added a comment to D35232: busdma_iommu: map without extra offset bytes.

panic: segment too large: ctx 0xfffff800041ca180 start 0xfef01000 end 0xfef24000 buflen1 0x23000 maxsegsz 0x22400

https://people.freebsd.org/~pho/stress/log/log0316.txt

May 18 2022, 8:09 PM

pho added a comment to D35232: busdma_iommu: map without extra offset bytes.

https://people.freebsd.org/~pho/stress/log/log0314.txt

May 18 2022, 10:20 AM

May 16 2022

pho added a comment to D35219: Comprehensive UFS/FFS superblock integrity checks made when a superblock is read.

I have uploaded a minimal test scenario, where the second mount fails with your patch:

mount-error.sh995 BDownload

May 16 2022, 1:05 PM

May 8 2022

pho committed rG13aacd0c0cb6: stress2: Added a test scenario (authored by pho).

stress2: Added a test scenario

May 8 2022, 7:58 AM

Apr 29 2022

pho committed rG014a2b1a1125: stress2: Fixed cleanup path error (authored by pho).

stress2: Fixed cleanup path error

Apr 29 2022, 8:56 AM

Apr 28 2022

pho committed rG8a5c1f58dd0e: stress2: Added a regression test (authored by pho).

stress2: Added a regression test

Apr 28 2022, 7:42 AM

Apr 22 2022

pho committed rG29acff870b5f: stress2: Added a syzkaller reproducer (authored by pho).

stress2: Added a syzkaller reproducer

Apr 22 2022, 4:21 AM

Apr 16 2022

pho committed rGeaa3e829f0e3: stress2: Added a regression test (authored by pho).

stress2: Added a regression test

Apr 16 2022, 7:16 AM

pho committed rGaf333da5063c: Added a test to the exclude list (authored by pho).

Added a test to the exclude list

Apr 16 2022, 7:16 AM

Apr 15 2022

pho added a comment to D34815: For multipage allocation, start block scan at start of free range.

D34815.104986.patch also looks good to me.

Apr 15 2022, 7:17 PM

pho added a comment to D34906: Revert rest of a5970a529c2d95271: use vrefact() when working on fp->f_vnode.

OTOH it would be useful if you provide Peter with your test program and instructions how to reproduce, so that this case does not regress more.

Apr 15 2022, 8:33 AM

Apr 14 2022

pho committed rG1346766f60ad: stress2: Permanently disable disruptive tests (authored by pho).

stress2: Permanently disable disruptive tests

Apr 14 2022, 5:00 AM

Apr 13 2022

pho committed rG2f0baec1ecb2: stress2: Fix cleanup after test run (authored by pho).

stress2: Fix cleanup after test run

Apr 13 2022, 9:09 AM

pho committed rGb06e3f990d94: stress2: Added comment (authored by pho).

stress2: Added comment

Apr 13 2022, 9:09 AM

pho committed rG4523edbeae50: stress2: Remove working tests from the exclude list (authored by pho).

stress2: Remove working tests from the exclude list

Apr 13 2022, 9:09 AM

Apr 11 2022

pho added a comment to D34815: For multipage allocation, start block scan at start of free range.

D34815.104865.patch LGTM

Apr 11 2022, 2:15 PM

Apr 10 2022

pho added a comment to D34815: For multipage allocation, start block scan at start of free range.

../../../vm/vm_phys.c:1360:6: error: unused variable 'order' [-Werror,-Wunused-variable]
        int order;
            ^
1 error generated.

Apr 10 2022, 1:30 PM

pho added a comment to D34815: For multipage allocation, start block scan at start of free range.

I got a panic with this: https://people.freebsd.org/~pho/stress/log/log0278.txt

Apr 10 2022, 9:35 AM

Apr 9 2022

pho added a comment to D34729: For multipage allocation, try assembling smaller blocks when big-enough free lists are empty.

I ran tests for 16 hours without seeing any problems with D34729.104761.patch

Apr 9 2022, 10:30 AM

Apr 6 2022

pho committed rG40b97c41bc77: stress2: Add new write(2) test. Remove sctp.sh after problem fixed (authored by pho).

stress2: Add new write(2) test. Remove sctp.sh after problem fixed

Apr 6 2022, 5:27 AM

pho committed rGb5c60bb85bf3: stress2: Added a write(2) fuzz test scenario (authored by pho).

stress2: Added a write(2) fuzz test scenario

Apr 6 2022, 5:27 AM

Apr 5 2022

pho committed rG7c1baa8ab3f5: stress2: Added a syzkaller reproducer (authored by pho).

stress2: Added a syzkaller reproducer

Apr 5 2022, 8:48 AM

Apr 3 2022

pho committed rG88b3e65fcff2: stress2: Added a test to the exclude file (authored by pho).

stress2: Added a test to the exclude file

Apr 3 2022, 9:13 AM

Apr 1 2022

pho added a comment to D34729: For multipage allocation, try assembling smaller blocks when big-enough free lists are empty.

I ran a four hour test with the contigmalloc() tests in a loop. This followed by random stress2 tests for 4 hours. No problems seen.

Apr 1 2022, 12:54 PM

Mar 31 2022

pho added a comment to D34724: Allow allocation of pages from beyond the last max order block of a range.

I'm not sure how much testing is required for this patch.
I ran the three contigmalloc(9) tests I have in a loop for four hours. I followed up with a few hours of random stress2 tests.
No problems seen.

Mar 31 2022, 7:55 PM

pho added a comment to D33947: Change free space search to avoid duplicate search.

The stress2 test suite completed with any issues.

Mar 31 2022, 5:28 AM