Your message dated Fri, 02 Jul 2021 16:03:32 +0000 with message-id <[email protected]> and subject line Bug#990573: fixed in pmdk 1.10-2 has caused the Debian Bug report #990573, regarding libpmem1: insufficient flushing on ARMv8.2+ to be marked as done.
This means that you claim that the problem has been dealt with. If this is not the case it is now your responsibility to reopen the Bug report if necessary, and/or fix the problem forthwith. (NB: If you are a system administrator and have no idea what this message is talking about, this may indicate a serious mail system misconfiguration somewhere. Please contact [email protected] immediately.) -- 990573: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=990573 Debian Bug Tracking System Contact [email protected] with problems
--- Begin Message ---Package: libpmem1 Version: 1.10-1 Severity: grave Justification: causes data loss [a fix is coming, filing this bug so the Release Team knows why] Hi! Support for arm64 in PMDK is deeply experimental. As far as I know, it has never been tested on real hardware nor had been reviewed by someone with adequate knowledge about ARM. Yet, enabling arm64 in our packages has been requested multiple times, and bullseye / buster-backports do include arm64 builds. This was done with porting in mind, yet it looks like pmem-capable ARM hardware is coming soon, and will be used in production not long after. This makes inadequate support for new ARM chips unfortunate to say the least. In ARMv8.0 and ARMv8.1, the only flushes available were CVAI (to make icache = dcache, irrelevant for pmem), and CVAC ("flush to coherency"). The latter was the deepest flush available, and implementors simply had no other option than to have this instruction request the memory controller to send its data to actual memory chips. This changed in ARMv8.2, where a new instruction CVAP ("flush to persistency") has been added, and CVAC was defined to require coherency only between "agents" (such as CPU cores, GPU, etc) but not memory. Yet PMDK knew only about CVAC -- despite asking around, no one of us could get hold of an ARMv8.2 machine to implement detection/etc. Such support is obviously not a priority for Intel nor IBM. Only recently, I managed to get access to such a box, and implemented flushes via CVAP. Without them, an unexpected power loss may result in recent writes being lost. This is even worse than with disks -- a typical filesystem will flush every 5 seconds or so, while there's no time-based mechanism to flush CPU caches. If a machine finished its task and became quiescent, it's possible the kernel and daemons won't actively touch more than 16-64MB of L3 cache for hours or days. The new flushes have been merged upstream in 1.11, I'm about to cherry-pick to 1.10 for Bullseye. Meow! -- System Information: Debian Release: 11.0 APT prefers unstable-debug APT policy: (500, 'unstable-debug'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 5.13.0-00032-g2fc675a48a0e (SMP w/64 CPU threads) Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en Shell: /bin/sh linked to /bin/dash Init: sysvinit (via /sbin/init) Versions of packages libpmem1 depends on: ii libc6 2.31-12 ii libdaxctl1 71.1-1 ii libndctl6 71.1-1 libpmem1 recommends no packages. libpmem1 suggests no packages. -- no debconf information
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--- Begin Message ---Source: pmdk Source-Version: 1.10-2 Done: Adam Borowski <[email protected]> We believe that the bug you reported is fixed in the latest version of pmdk, which is due to be installed in the Debian FTP archive. A summary of the changes between this version and the previous one is attached. Thank you for reporting the bug, which will now be closed. If you have further comments please address them to [email protected], and the maintainer will reopen the bug report if appropriate. Debian distribution maintenance software pp. Adam Borowski <[email protected]> (supplier of updated pmdk package) (This message was generated automatically at their request; if you believe that there is a problem with it please contact the archive administrators by mailing [email protected]) -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Format: 1.8 Date: Fri, 02 Jul 2021 17:02:37 +0200 Source: pmdk Architecture: source Version: 1.10-2 Distribution: unstable Urgency: high Maintainer: Adam Borowski <[email protected]> Changed-By: Adam Borowski <[email protected]> Closes: 990573 Changes: pmdk (1.10-2) unstable; urgency=high . * Fix insufficient flushing on ARMv8.2+ (closes: #990573). Checksums-Sha1: 51b90651718942bb92cb7f7fd662851974428b7e 3841 pmdk_1.10-2.dsc a9bfccf9711ee65bdfd6bfc871b28f851a2df6f4 17316 pmdk_1.10-2.debian.tar.xz dbd0bec530bb1904adc7b7e7cd30c4a552d94abb 6741 pmdk_1.10-2_source.buildinfo Checksums-Sha256: ec245dad59c5b89993c8e6725fde9bd81e88f97f43632fb7afe048b69a1cc31f 3841 pmdk_1.10-2.dsc 0d44d6eb39f3898545d4e12f72a3ba04f70d7ae2af1f66e830806db3c5f3f608 17316 pmdk_1.10-2.debian.tar.xz d44c6a2d65ca94b28f70432c0e06d32991aef85fd9b2129321214f06b74d4acf 6741 pmdk_1.10-2_source.buildinfo Files: f0f7762b1dba8ca63135d083ffeb7013 3841 libs optional pmdk_1.10-2.dsc b754fa9577b038869630b531e8cdab57 17316 libs optional pmdk_1.10-2.debian.tar.xz ae5714d7ffbdff769f09f44f2432f962 6741 libs optional pmdk_1.10-2_source.buildinfo -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEkjZVexcMh/iCHArDweDZLphvfH4FAmDfM/8ACgkQweDZLphv fH6teRAA1ODp3hZIkXsaM0dZgp6IwKPkHMfh7V/s9drC0Gx844oIvJzn5ygSiQcQ 6QNT/FEkdIFPXUMABeD+MmuZtWMD+rdAtDYHfCda5/8EUBjx2VpLxiZsE+q18xG3 MgLxgHHqCU4n+XgG0yUk8/o8/ouIePwxVQkNefbda6c7ynu8qUpf9UtcClDGIbFy yMjtadp98uyCJ5dzkiTmEorES+niWDj0gRWYEOGRhTka0gf7lymijqika1SQMw1X TMl/8hy+u4hQnoDGzDWR3JZnK5RaZPb2+SBwyewG/DcDSdhWxT+fLJME+0OFIo8P buSjzMi7ozPbpa7iUUgyyDOHZcNnI2cR9FqRC675PX7og0b0c31f0N+qKbWpHlyh gQ0CkqrnnWIKW6mRzItC4VuOMMqp1kwbc/BgEOt+0+CS2RET9XlApZzgsKkrScmQ /kJMQlorW9llAdcFi/gepjfhZTBgFfDTMYiroQtsol892D3bYiKWRxHwtjirp8xc f4VlQY5QBabfTuhb+uYq/DMFBWI5cO2CwRUpz7g4hEvHPcY6AFGwWboYh0uON8Y8 BmOkltYiuK0eUOr97vILOAnwT+gdHopo2PG2eredxOnhlnEwONaUx/qZg71hAUkH vrncdnUmZ9z1976WuhpOriTkcXH8eUSePVCuJoPqC6/ukMlZ9KY= =snQ8 -----END PGP SIGNATURE-----
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