Bug #75835 O_DIRECT cannot be used on tmpfs - can this be changed?
Submitted: 10 Feb 2015 7:53
Reporter: Roel Van de Paar (OCA) Email Updates:
Status: Open Impact on me:
None 
Category:MySQL Server Severity:S4 (Feature request)
Version:5.6,5.7 OS:Any
Assigned to: CPU Architecture:Any

[10 Feb 2015 7:53] Roel Van de Paar
Description:
2015-02-10T06:48:50.409394Z 0 [Warning] InnoDB: Failed to set O_DIRECT on file ./ibdata1: OPEN: Invalid argument, continuing anyway. O_DIRECT is known to result  in 'Invalid argument' on Linux on tmpfs, see MySQL Bug#26662.

http://bugs.mysql.com/bug.php?id=26662
http://bugs.mysql.com/bug.php?id=58421

How to repeat:
Try and use O_DIRECT on tmpfs

Suggested fix:
This restriction is old. Is it still necessary? Can O_DIRECT now be allowed on tmpfs? It would help with QA.