linux-kernel - tick issue: tick_setup

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>] [day] [month] [year] [list]

Message-ID: <CAK9wHMR+TbN4cFLOvHPz=mVALnc4+oevVpvDrhaWdLE3yXW8XA@mail.gmail.com>
Date:	Sat, 2 Jul 2011 10:12:42 +0800
From:	chao xie <xiechao.linux@...il.com>
To:	linux-kernel@...r.kernel.org
Subject: tick issue: tick_setup_device()

hi
I am very strange about this function.
In this function, it has
/*
        * When the device is not per cpu, pin the interrupt to the
        * current cpu:
        */
       if (!cpumask_equal(newdev->cpumask, cpumask))
               irq_set_affinity(newdev->irq, cpumask);

When the clock event device has cpu_mask set to be cpumask_of(1), it
means that the device is bound to cpu1. So above code has covered it,
but why we have "!cpumask_equal(newdev->cpumask, cpumask)"?
if the "newdev->cpumask" equals "cpumask", cpumask_equal will return
1, and at this situation we will set the irq affinity because the
device is bound to the dedicated cpu.

Is there a bug, or i understand wrong about cpumask of clock_event_device?
Thanks.
--
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/