Re: strange message before sending mail

On 2026-08-19 18:43:34 +0100, Ian Collier via Mutt-dev wrote:
> On modern systems HZ=1000, but my testing showed a delay of up to 1.53ms
> on x86_64 and 1.08ms on arm64.

A correction on this: Under Linux, the time(7) man page says:

  The  value  of  HZ  varies  across  kernel  versions  and  hardware
  platforms.  On i386 the situation is as follows: on kernels  up  to
  and including Linux 2.4.x, HZ was 100, giving a jiffy value of 0.01
  seconds; starting with Linux 2.6.0, HZ was raised to 1000, giving a
  jiffy  of  0.001  seconds.   Since  Linux 2.6.13, the HZ value is a
  kernel configuration parameter and can be 100, 250 (the default) or
  1000, yielding a jiffies value of, respectively,  0.01,  0.004,  or
  0.001   seconds.   Since  Linux  2.6.20,  a  further  frequency  is
  available: 300, a number that divides evenly for the  common  video
  frame rates (PAL, 25 Hz; NTSC, 30 Hz).

So most Linux users would expect HZ=250 (a jiffy of 0.004 s = 4 ms).

This is my case:

qaa:~> grep '^CONFIG_HZ=' /boot/config-$(uname -r)
CONFIG_HZ=250

BTW, I can reproduce the issue with

qaa:~> /usr/bin/stat /var/tmp/mutt-qaa-1000-*
  File: /var/tmp/mutt-qaa-1000-2882-16034754240795970957
  Size: 227             Blocks: 8          IO Block: 4096   regular file
Device: 254,1   Inode: 13252683    Links: 1
Access: (0600/-rw-------)  Uid: ( 1000/  vinc17)   Gid: ( 1000/  vinc17)
Access: 2026-08-20 10:10:25.003735485 +0200
Modify: 2026-08-20 10:10:25.003700613 +0200
Change: 2026-08-20 10:10:25.003700613 +0200
 Birth: 2026-08-20 10:10:25.003367902 +0200

0.003700613 is a little less than the 0.004 s jiffy.

So I would expect the issue to occur with a frequency of about 1/250.

-- 
Vincent Lefèvre <[email protected]> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / Pascaline project (LIP, ENS-Lyon)