UCSF Memory & Aging Center channel on YouTube & ‘Fight for Mike’

Even tech people in Silicon Valley need to join their powerful forces and sources when it is about aging related neurodegenerative diseases and help research and the clinic.

UCSF Memory and Aging Center channel on YouTube 

Om Malik: A Personal Note: Pause & Read via John Battelle

 

2 thoughts on “UCSF Memory & Aging Center channel on YouTube & ‘Fight for Mike’

  1. Soft-updates guarantees that the only filesystem inconsistencies on unclean shutdown are leaked blocks and inodes. To resolve this you can run a background fsck or you can ignore it until you start to run out of space. We also could’ve written a mark and sweep garbage collector but never did. Ultimately, the bgfsck is too expensive and people did not like the uncertainty of not having run fsck. To resolve these issues, I have added a small journal to softupdates. However, I only have to journal block allocation and free, and inode link count changes since softdep guarantees the rest. My journal records are each only 32bytes which is incredibly compact compared to any other journaling solution. We still get the great concurrency and ability to ignore writes which have been canceled by new operations. But now we have recovery time that is around 2 seconds per megabyte of journal in-use. That’s 32,768 blocks allocated, files created, links added, etc. per megabyte of journal.

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