Re: [linux-pm] Resume from Memory very slow on 2.6.37+

Rafael J. Wysocki
2011-01-19T01:39:23Z

On Wednesday, January 19, 2011, Jeff Chua wrote:
> On Wed, Jan 19, 2011 at 4:20 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > Please apply the appended patch (without the previous one) and post a dmesg
> > log containing a suspend-resume cycle with the delay. I wonder where exactly
> > the delay occurs.
> > + pr_info("%s: synchronize_rcu()\n", __func__);
> > synchronize_rcu();
> > + pr_info("%s: iounmap(%p), physaddr: %llx, size: %u\n", __func__,
> > + map->virt, map->phys, map->size);
>
> Rafael,
>
> The 30 seconds is due to this ...
>
> PM: Syncing filesystems ... done.
> Freezing user space processes ... _memory: synchronize_rcu()
> acpi_os_unmap_memory: iounmap(ffffc90001c22000), physaddr: bb398000, size: 4096
> acpi_os_unmap_memory: synchronize_rcu()
> acpi_os_unmap_memory: iounmap(ffffc90001c26000), physaddr: bb399000, size: 4096
> acpi_os_unmap_memory: synchronize_rcu()
> acpi_os_unmap_memory: iounmap(ffffc90001c2a000), physaddr: bb39a000, size: 4096
> acpi_os_unmap_memory: synchronize_rcu()
> acpi_os_unmap_memory: iounmap(ffffc90001c2e000), physaddr: bb39b000, size: 4096
> <repeat till ...>
> acpi_os_unmap_memory: iounmap(ffffc90003538000), physaddr: bb79d000, size: 4096
> acpi_os_unmap_memory: synchronize_rcu()
> acpi_os_unmap_memory: iounmap(ffffc9000353c000), physaddr: bb79e000, size: 4096
> Restarting tasks ... done.
>
> After this, I see my X windows.

Are you able to say whether the synchronize_rcu() or the iounmap() calls block?

Rafael