From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hongzhi, Song Date: Fri, 19 Jul 2019 16:13:08 +0800 Subject: [LTP] Question about kernel/syscall/signal/signal06.c In-Reply-To: <20190717094614.GA9539@rei> References: <56f854e2-9cc6-4725-3182-ff83e106ee23@windriver.com> <20190717094614.GA9539@rei> Message-ID: <7d2c4936-2e89-6285-c856-a156d3a76284@windriver.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it This case fails when boot qemux86-64 with 1/2 cores. I find [kernel 5.2-rc1: 0d714dba162] causes the failure by git bisect. If git checkout a commit before 0d714dba162, the case will pass on the same qemu configuration. --Hongzhi On 7/17/19 5:46 PM, Cyril Hrubis wrote: > Hi! >> I find signal06 fails on qemux86-64 when qemu has a small number cores, >> e.g. "qemu -smp 1/2/4/6". >> >> ERROR INFO: >> >> signal06?????? 0?? TINFO?? :?? loop = 23 >> signal06?????? 1?? TFAIL?? :?? signal06.c:87: Bug Reproduced! >> >> But if boot qemu with "-smp 16", the case has great chance to pass. >> >> >> I have two questions about this case: >> >> 1. I don't know why multi-core will affect the case. > Have you looked into the code? The test is trying to reproduce a race > condition between two threads of course the number of cores does affect > the reproducibility. > >> 2. On failure situation, what does break the "while loop" shown in below >> code. > Bug in a kernel that fails to restore fpu state. >