Messages in this thread | | | Date | Tue, 16 Nov 2004 20:14:35 -0800 | From | Andrew Morton <> | Subject | Re: vm-pageout-throttling.patch: hanging in throttle_vm_writeout/blk_congestion_wait |
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Hans Reiser <reiser@namesys.com> wrote: > > >>>loop-AES-2.2d)... I think (!) it caused this deadlock. > >>> > >>> > >>That's not at all surprising. See the swap_extent work Andrew did > >>for 2.5 (in mm/swapfile.c), by which swap to a swapfile now avoids > >>the filesystem altogether (except while swapon prepares the map of > >>disk blocks). By swapping to a loop device over a file, you're > >>sneaking past his work, and putting the filesystem back under swap. > >> > >> > > Does Andrew's approach prevent putting swap on a compressed file (useful > for reiser4 once the compression plugin is stable, not reiserfs)? (And > no, I don't have any idea what the performance effect of that would be > before it is tried and benchmarked....)
swapfiles bypass the filesystem completely, so if you're implementing compression at the writepage() level, swap will cheerfully ignore all that and will launch submit_bio() direct against your blockdev anyway.
encrypted swap should be done via dm-crypt. compressed swap would I guess require dm-compress. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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