This patch replaces pause instruction with SwitchToThread() call in wait loop in lock() to increase the chance to unlock in other threads.
Addresses: https://cygwin.com/pipermail/cygwin/2024-November/256744.html Fixes: 61522196c715 ("* Merge in cygwin-64bit-branch.") Reported-by: Christian Franke <christian.fra...@t-online.de> Reviewed-by: Signed-off-by: Takashi Yano <takashi.y...@nifty.ne.jp> --- winsup/cygwin/scripts/gendef | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/winsup/cygwin/scripts/gendef b/winsup/cygwin/scripts/gendef index 720325fdd..d1bcc5318 100755 --- a/winsup/cygwin/scripts/gendef +++ b/winsup/cygwin/scripts/gendef @@ -115,6 +115,8 @@ EOF .include "tlsoffsets" .text + .global SwitchToThread + .seh_proc _sigfe_maybe _sigfe_maybe: # stack is aligned on entry! .seh_endprologue @@ -334,7 +336,7 @@ _ZN7_cygtls4lockEv: xchgl %r11d,_cygtls.stacklock_p(%r12) # try to acquire lock testl %r11d,%r11d jz 2f - pause + call SwitchToThread jmp 1b 2: popq %r12 ret -- 2.45.1
