lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 19 Dec 2014 15:36:45 -0500
From:	Dave Jones <davej@...hat.com>
To:	Chris Mason <clm@...com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Mike Galbraith <umgwanakikbuti@...il.com>,
	Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Dâniel Fraga <fragabr@...il.com>,
	Sasha Levin <sasha.levin@...cle.com>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Suresh Siddha <sbsiddha@...il.com>,
	Oleg Nesterov <oleg@...hat.com>,
	Peter Anvin <hpa@...ux.intel.com>
Subject: Re: frequent lockups in 3.18rc4

On Fri, Dec 19, 2014 at 03:31:36PM -0500, Chris Mason wrote:

 > > So it's not stuck *inside* read_hpet(), and it's almost certainly not
 > > the loop over the sequence counter in ktime_get() either (it's not
 > > increasing *that* quickly). But some basically infinite __run_hrtimer
 > > thing or something?
 > 
 > Really interesting.
 > 
 > So, we're calling __run_hrtimer in a loop:
 > 
 >                 while ((node = timerqueue_getnext(&base->active))) {
 > 				...
 > 				__run_hrtimer(timer, &basenow);
 > 				...
 > 		}
 > 
 > The easy question is how often does trinity call nanosleep?

It shouldn't call it directly. (syscalls/nanosleep.c)

/*
 * SYSCALL_DEFINE2(nanosleep, struct timespec __user *, rqtp, struct timespec __user *, rmtp)
 */
#include "sanitise.h"

struct syscallentry syscall_nanosleep = {
	.name = "nanosleep",
	.num_args = 2,
	.arg1name = "rqtp",
	.arg1type = ARG_ADDRESS,
	.arg2name = "rmtp",
	.arg2type = ARG_ADDRESS,
	.flags = AVOID_SYSCALL, // Boring.  Can cause long sleeps.
};


That last line being the key one.  We used to do it, but it's well.. boring.
We could do something smarter, but given it's never triggered anything
interesting in the past, focussing runtime on the more interesting
syscalls seems to have been more fruitful.

	Dave

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists