• Open Menu Close Menu
  • Apple
  • Shopping Bag
  • Apple
  • Mac
  • iPad
  • iPhone
  • Watch
  • TV
  • Music
  • Support
  • Search apple.com
  • Shopping Bag

Lists

Open Menu Close Menu
  • Terms and Conditions
  • Lists hosted on this site
  • Email the Postmaster
  • Tips for posting to public mailing lists
Re: APFS: mmap page fault can take up to minutes after ftruncate/F_PREALLOCATE
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: APFS: mmap page fault can take up to minutes after ftruncate/F_PREALLOCATE


  • Subject: Re: APFS: mmap page fault can take up to minutes after ftruncate/F_PREALLOCATE
  • From: Thomas Tempelmann via Filesystem-dev <email@hidden>
  • Date: Thu, 19 Dec 2019 16:15:27 +0100

Out of curiosity, I just ran the test on my 10.13.6 system:

On HFS+, the tool finishes in about 5 seconds, ending up with a 4 GB file.

However, on a freshly created APFS vol (no encryption, on same SSD as the
HFS+ volume), it runs for about an hour! But no extra wait time around 2 GB.

I guess that APFS's mmap was so slow on 10.13 that the Apple engineers
optimized this in 10.14, but still with a hiccup at 2GB. And then fixed
that as well in 10.15.

Thomas

>
 _______________________________________________
Do not post admin requests to the list. They will be ignored.
Filesystem-dev mailing list      (email@hidden)
Help/Unsubscribe/Update your Subscription:

This email sent to email@hidden

References: 
 >APFS: mmap page fault can take up to minutes after ftruncate/F_PREALLOCATE (From: Ilia K via Filesystem-dev <email@hidden>)

  • Prev by Date: Re: APFS: mmap page fault can take up to minutes after ftruncate/F_PREALLOCATE
  • Previous by thread: Re: APFS: mmap page fault can take up to minutes after ftruncate/F_PREALLOCATE
  • Index(es):
    • Date
    • Thread