Hi Takashi,
Takashi Yano wrote:
Hi Christian,
On Fri, 11 Apr 2025 16:46:07 +0200
Christian Franke wrote:
In rare cases, '/bin/kill -f PID' hangs because kill(2) is always tried
first. With this patch, this could be prevented with '/bin/kill -f -s -
PID'.
I wonder why kill(2) hangs. Do you have any idea?
Sorry no. I observed this in early (Cygwin 3.5.4) testing of stress-ng
for ITP, but could no longer reproduce it.
Here are tests which currently (3.7.0-0.51.gd35cc82b5ec1) ignore but not
hang kill(pid, SIGKILL):
stress-ng --mprotect 1 -t 5 -v
stress-ng --priv-instr 1 -t 5 -v
stress-ng --sigchld 1 -t 5 -v
stress-ng --sigsegv 1 -t 5 -v
Run this in another window to see that child processes are left behind:
killall -v -9 stress-ng; sleep 4; taskkill /F /T /IM stress-ng.exe
For a minimal testcase regarding --priv-instr, see:
https://sourceware.org/pipermail/cygwin/2025-March/257726.html
If kill(2) hangs in some cases, shouldn't we fix that
rather than patching to kill(1)?
Of course. This feature was intended as a first step for an 'onboard'
tool for the CI tests suggested by Jon Turney. A second step could be an
--all option to replace 'taskill' or 'pskill'.
--
Regards,
Christian
