On Tue, Dec 7, 2010 at 12:22 PM, Mike Snitzer <snitzer@xxxxxxxxxx> wrote: > On Tue, Dec 07 2010 at Â1:10pm -0500, > Jon Nelson <jnelson@xxxxxxxxxxx> wrote: > >> I finally found some time to test this out. With 2.6.37-rc4 (openSUSE >> KOTD kernel) I easily encounter the issue. >> >> Using a virtual machine, I created a stock, minimal openSUSE 11.3 x86_64 >> install, installed all updates, installed postgresql and the 'KOTD' >> (Kernel of the Day) >> kernel, and ran the following tests (as postgres user because I'm >> lazy). >> >> 1. create a database (from bash): >> >> createdb test >> >> 2. place the following contents in a file (I used 't.sql'): >> >> begin; >> create temporary table foo as select x as a, ARRAY[x] as b FROM >> generate_series(1, 10000000 ) AS x; >> create index foo_a_idx on foo (a); >> create index foo_b_idx on foo USING GIN (b); >> rollback; >> >> 3. execute that sql: >> >> psql -f t.sql --echo-all test >> >> >> With 2.6.34.7 I can re-run [3] all day long, as many times as I want, >> without issue. >> >> With 2.6.37-rc4-13 (the currently-installed KOTD kernel) if tails >> pretty frequently. > > How does it fail? Âpostgres errors? Âkernel errors? postgresql errors. Typically, header corruption but from the limited visibility I've had into this via strace, what I see is zeroed pages where there shouldn't be. I just ran a test and got: ERROR: invalid page header in block 37483 of relation base/16384/16417 but that is not the only error one might get. >> Then I tested with the 'vanilla' kernel available here: >> >> http://download.opensuse.org/repositories/Kernel:/vanilla/standard/ >> >> The 'vanilla' kernel exhibited the same problems. >> The version I tested: Â2.6.37-rc4-219-g771f8bc-vanilla. >> >> Incidentally, quick tests of jfs, xfs, and ext3 do _not_ show the same >> problems, although I will note that I usually saw failure at least 1 >> in 3, but sometimes had to re-run the sql test 4 or 5 times before I >> saw failure. >> >> I will continue to do some testing, but I will hold off on testing the >> commits above until I receive further testing suggestions. > > OK, so to be clear: your testing is on dm-crypt + ext4? Yes. I took a virtual hard disk which shows up as /dev/sdb, used cryptsetup to format it as a LUKS volume, mounted the LUKS volume, formatted as ext4 (or whatever), mounted that, rsync'd over a blank postgresql 'data' directory, started postgresql, became the postgres user, and proceeded to create the db and run the sql. > And you're testing upstream based kernels (meaning the dm-crypt > scalability patch that has been in question is _not_ in the mix)? I am testing both the KOTD kernels and the "vanilla" kernels - neither of which has the dm-crypt patches (as far as I know). -- Jon -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
