Hi Thierry, Op 9-5-2018 om 18:30 schreef Thierry Fournier:
It seems a dead lock, but you observe a loop.Effectively it is a deadlock, it keeps looping over these few lines of code below from xref.h <http://git.haproxy.org/?p=haproxy.git;a=blob_plain;f=include/common/xref.h;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b>.. The XCHG just swaps the 2 values (both are '1') and continues on, then the local==BUSY check is true it loops and swaps 1 and 1 again, and the circle continues..
Thanks for looking into it :) Ill try and get 'simpler' reproduction with some well placed sleep() as you suggest.
Regards, PiBa-NL http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b31 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l31> while (1) { 32 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l32> 33 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l33> /* Get the local pointer to the peer. */ 34 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l34> local = HA_ATOMIC_XCHG(&xref->peer, XREF_BUSY); 35 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l35> 36 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l36> /* If the local pointer is NULL, the peer no longer exists. */ 37 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l37> if (local == NULL) { 38 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l38> xref->peer = NULL; 39 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l39> return NULL; 40 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l40> } 41 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l41> 42 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l42> /* If the local pointeru is BUSY, the peer try to acquire the 43 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l43> * lock. We retry the process. 44 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l44> */ 45 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l45> if (local == XREF_BUSY) 46 <http://git.haproxy.org/?p=haproxy.git;a=blob;f=include/common/xref.h;h=6dfa7b62758dfaebe12d25f66aaa858dc873a060;hb=29d698040d6bb56b29c036aeba05f0d52d8ce94b#l46> continue;
