READFILE System Call Rebased For More Efficient Reading Of Small Files

Written by Michael Larabel in Linux Storage on 3 April 2021 at 08:34 AM EDT. 51 Comments
The past year there has been work led by Greg Kroah-Hartman on a "READFILE" system call for efficiently reading small files such as for data exposed via sysfs. While not yet mainlined, this week the patches for this new system call were re-based giving us hope that perhaps we'll see it with Linux 5.13.

The READFILE system call aims to make it very efficient to read small files straight into a buffer with a single system call rather than the traditional open/read/close approach with multiple system calls.

This system call didn't see much activity at first but then later in the year the prospects of it getting picked up for mainline were renewed with finding a potential user of this new system call.

Now a few weeks out from the Linux 5.13 merge window, Greg Kroah-Hartman happened to re-based the patches against the latest Linux Git upstream state.

As of this morning Greg's driver-core.git readfile branch has seen the READFILE system call patches re-based against Linux 5.12.

We'll see if it goes for mainline this time around. Again, the main use-case of this system call would be for frequently reading small files for efficiently. The readfile documentation can be found via the man page commit.
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