Bug 203647
| Summary: | Locking API testsuite fails "mixed read-lock/lock-write ABBA" rlock on kernels >=4.14.x | ||
|---|---|---|---|
| Product: | Platform Specific/Hardware | Reporter: | Erhard F. (erhard_f) |
| Component: | PPC-64 | Assignee: | platform_ppc-64 |
| Status: | RESOLVED DOCUMENTED | ||
| Severity: | normal | CC: | matorola, michael |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 5.1.3 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
dmesg (5.1.3, G5 11,2)
dmesg (5.0.17, G5 11,2) dmesg (4.19.44, G5 11,2) dmesg (4.14.120, G5 11,2) dmesg (4.9.177, G5 11,2) kernel .config (5.1.3, G5 11,2) |
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Created attachment 282833 [details]
dmesg (5.0.17, G5 11,2)
Created attachment 282835 [details]
dmesg (4.19.44, G5 11,2)
Created attachment 282837 [details]
dmesg (4.14.120, G5 11,2)
Created attachment 282839 [details]
dmesg (4.9.177, G5 11,2)
Created attachment 282841 [details]
kernel .config (5.1.3, G5 11,2)
This appears to be working as expected, which I admit is a little confusing. The key thing is that at the end you see, eg: [ 0.179788] Good, all 261 testcases passed! | See the commit that added the test: https://git.kernel.org/torvalds/c/e91498589746 locking/lockdep/selftests: Add mixed read-write ABBA tests Currently lockdep has limited support for recursive readers, add a few mixed read-write ABBA selftests to show the extend of these limitations. And in the code: print_testname("mixed read-lock/lock-write ABBA"); pr_cont(" |"); dotest(rlock_ABBA1, FAILURE, LOCKTYPE_RWLOCK); #ifdef CONFIG_PROVE_LOCKING /* * Lockdep does indeed fail here, but there's nothing we can do about * that now. Don't kill lockdep for it. */ unexpected_testcase_failures--; #endif it's the same for sparc64: ` [ 0.000020] PROMLIB: Sun IEEE Boot Prom 'OBP 4.38.12 2018/03/28 14:54' [ 0.000032] PROMLIB: Root node compatible: sun4v [ 0.000080] Linux version 5.2.0-10808-g9637d517347e (mator@ttip) (gcc version 8.3.0 (Debian 8.3.0-7)) #1080 SMP Tue Jul 16 10:46:19 MSK 2019 [ 0.000386] printk: bootconsole [earlyprom0] enabled [ 0.000441] ARCH: SUN4V ... [ 0.451068] memory used by lock dependency info: 3855 kB [ 0.451104] per task-struct memory footprint: 1920 bytes [ 0.451140] ------------------------ [ 0.451167] | Locking API testsuite: [ 0.451194] ---------------------------------------------------------------------------- [ 0.451244] | spin |wlock |rlock |mutex | wsem | rsem | [ 0.451294] -------------------------------------------------------------------------- [ 0.451350] A-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.454281] A-B-B-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.457443] A-B-B-C-C-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.460744] A-B-C-A-B-C deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.464032] A-B-B-C-C-D-D-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.467545] A-B-C-D-B-D-D-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.471009] A-B-C-D-B-C-D-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.474475] double unlock: ok | ok | ok | ok | ok | ok | ok | [ 0.477425] initialize held: ok | ok | ok | ok | ok | ok | ok | [ 0.480301] -------------------------------------------------------------------------- [ 0.480352] recursive read-lock: | ok | | ok | [ 0.481247] recursive read-lock #2: | ok | | ok | [ 0.482120] mixed read-write-lock: | ok | | ok | [ 0.482998] mixed write-read-lock: | ok | | ok | [ 0.483878] mixed read-lock/lock-write ABBA: |FAILED| | ok | [ 0.484755] mixed read-lock/lock-read ABBA: | ok | | ok | [ 0.485676] mixed write-lock/lock-write ABBA: | ok | | ok | [ 0.486597] -------------------------------------------------------------------------- ` |
Created attachment 282831 [details] dmesg (5.1.3, G5 11,2) Probably this test fails on ppc64 since it is around. Kernel 4.9.x passes all tests, since it does not seem to contain "mixed read-lock/lock-write ABBA". Machine is a PowerMac G5 11,2 running Gentoo Linux ppc64, Big Endian, 4 KiB pagesize. [ 0.002051] ------------------------ [ 0.002065] | Locking API testsuite: [ 0.002079] ---------------------------------------------------------------------------- [ 0.002111] | spin |wlock |rlock |mutex | wsem | rsem | [ 0.002142] -------------------------------------------------------------------------- [ 0.002179] A-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.007366] A-B-B-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.012471] A-B-B-C-C-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.017598] A-B-C-A-B-C deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.022740] A-B-B-C-C-D-D-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.027912] A-B-C-D-B-D-D-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.033083] A-B-C-D-B-C-D-A deadlock: ok | ok | ok | ok | ok | ok | ok | [ 0.038269] double unlock: ok | ok | ok | ok | ok | ok | ok | [ 0.043319] initialize held: ok | ok | ok | ok | ok | ok | ok | [ 0.048379] -------------------------------------------------------------------------- [ 0.048411] recursive read-lock: | ok | | ok | [ 0.049894] recursive read-lock #2: | ok | | ok | [ 0.051375] mixed read-write-lock: | ok | | ok | [ 0.052859] mixed write-read-lock: | ok | | ok | [ 0.054333] mixed read-lock/lock-write ABBA: |FAILED| | ok | [ 0.055802] mixed read-lock/lock-read ABBA: | ok | | ok | [ 0.057290] mixed write-lock/lock-write ABBA: | ok | | ok | [ 0.058771] --------------------------------------------------------------------------