From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4B8C29E1.7070404@domain.hid> Date: Mon, 01 Mar 2010 21:56:01 +0100 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <4B86EDC2.7010905@domain.hid> <4B86FCBB.10203@domain.hid> <4B86FFA0.3000403@domain.hid> <4B870134.2040802@domain.hid> <4B87FC70.90903@domain.hid> <4B8C2490.1040604@domain.hid> <4B8C25B9.8090705@domain.hid> <4B8C26F7.3020306@domain.hid> <4B8C2797.2000501@domain.hid> In-Reply-To: <4B8C2797.2000501@domain.hid> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] mlockall error after calling mlockall() List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: "xenomai@xenomai.org" Jan Kiszka wrote: > Jan Kiszka wrote: >> Gilles Chanteperdrix wrote: >>> Jan Kiszka wrote: >>>> Charlton, John wrote: >>>>> I added some printk output to the cond.c file in xenomai-2.5.1 and it shows that xnsync_sleep_on returned -ETIMEDOUT as it should: >>>>> Xenomai: registered exported object M1-1908 (mutexes) >>>>> Xenomai: registered exported object C1-1908 (condvars) >>>>> xnsynch_sleep_on returned: -110 >>>>> xnsynch_sleep_on returned: -110 >>>>> xnsynch_sleep_on returned: -110 >>>>> xnsynch_sleep_on returned: -110 >>>>> xnsynch_sleep_on returned: -110 >>>>> xnsynch_sleep_on returned: -110 >>>>> xnsynch_sleep_on returned: -4 >>>>> Xenomai: native: cleaning up cond "C1-1908" (ret=0). >>>>> Xenomai: unregistered exported object C1-1908 (condvars) >>>>> Xenomai: native: cleaning up mutex "M1-1908" (ret=0). >>>>> Xenomai: unregistered exported object M1-1908 (mutexes) >>>>> Xenomai: POSIX: destroyed thread df5a0800 >>>>> >>>>> I put the printk on line cond.c:433 after err is set in rt_cond_wait_prologue(): >>>>> >>>>> info = xnsynch_sleep_on(&cond->synch_base, >>>>> timeout, timeout_mode); >>>>> if (info & XNRMID) >>>>> err = -EIDRM; /* Condvar deleted while pending. */ >>>>> else if (info & XNTIMEO) { >>>>> err = -ETIMEDOUT; /* Timeout. */ >>>>> } >>>>> else if (info & XNBREAK) { >>>>> err = -EINTR; /* Unblocked. */ >>>>> } >>>>> printk(KERN_DEBUG "xnsynch_sleep_on returned: %d\n", err); >>>>> >>>>> I put a printk in rt_cond_wait_inner() which is called directly by rt_cond_wait() from user mode but did not see the output in the dmesg output for that one. >>>> One of our problems is the prologue/epilogue split up (both in kernel >>>> and user space): the epilogue can eat the error code or the prologue, >>>> including the -ETIMEDOUT. >>> Ah. My fault. Looks user-space is Ok though. Only kernel-space has a >>> problem. >>> >> Both are affected. >> >> Could you help me with what issues >> 97323b3287b5ee8cad99a7fa67cd050bc51f76c4 should fix? > > Ah, restart after RT-signals! So far we blocked on the concluding > rt_mutex_lock without breaking out to user space, now we have to loop > over -EINTR to allow signals, right? Yes, it is needed even for handling linux signals (getting gdb working for instance). However, since we do not want rt_cond_wait to result into two syscalls all the time, we handle everything in the first syscall if possible. Try this: diff --git a/ksrc/skins/native/syscall.c b/ksrc/skins/native/syscall.c index 40e5cfd..d4e885c 100644 --- a/ksrc/skins/native/syscall.c +++ b/ksrc/skins/native/syscall.c @@ -1869,9 +1869,12 @@ static int __rt_cond_wait_prologue(struct pt_regs *regs) err = rt_cond_wait_prologue(cond, mutex, &lockcnt, timeout_mode, timeout); - if (err == 0 || err == -ETIMEDOUT) - err = rt_cond_wait_epilogue(mutex, lockcnt); - + if (err == 0 || err == -ETIMEDOUT) { + int loc_err = rt_cond_wait_epilogue(mutex, lockcnt); + if (loc_err < 0) + err = loc_err; + } + if (err == -EINTR && __xn_reg_arg3(regs) && __xn_safe_copy_to_user((void __user *)__xn_reg_arg3(regs), &lockcnt, sizeof(lockcnt))) > > Jan > -- Gilles.