Re: 2.6.21-rc suspend regression: sysfs deadlock

On Thu, 15 Mar 2007, Hugh Dickins wrote: > > sysfs_access_in_other_task() left me wondering what this "other" task > was, and what kind of "access" it's trying to get - or is the calling > task the other, and it's trying to access something it wouldn't > directly have access to? For naming clas

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Thu, 15 Mar 2007, Alan Stern wrote: > > Personally I don't understand what was wrong with my name. What's weird > or unintuitive about doing something in a different task's context? The only thing wrong with sysfs_do_something_in_a_different_task_context() is the length of the name. "do", t

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Thu, 15 Mar 2007 10:27:19 -0400 (EDT), Alan Stern <[EMAIL PROTECTED]> wrote: > Fair enough. One use of "delay" is in a comment you wrote; I'll change it > as well. Fine with me. > Would people be happier with sysfs_schedule_callback() and > device_schedule_callback()? At least the function

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Thu, 15 Mar 2007, Cornelia Huck wrote: > > > The naming seems a bit unintuitive, but I don't have a good > > > alternative idea. Perhaps sysfs_work_struct, sysfs_delayed_work()? > > > > sysfs_work_struct is too generic; other parts of sysfs might also want to > > use workqueues for different p

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Thu, 15 Mar 2007, Dmitry Torokhov wrote: > > How about sysfs_schedule_work? That is what it does - schedules a work > on a sysfs object and everyone here knows what schedule_work() does. I'm ashamed to have suggested anything else: certainly gets my vote. Hugh - To unsubscribe from this list:

Re: 2.6.21-rc suspend regression: sysfs deadlock

On 3/15/07, Oliver Neukum <[EMAIL PROTECTED]> wrote: Am Donnerstag, 15. März 2007 13:31 schrieb Hugh Dickins: > Quite apart from this mysterious "other task", I don't understand > "access" either. > > Perhaps "defer" would best capture the idea of another-task and > maybe-delay? sysfs_defer_work(

Re: 2.6.21-rc suspend regression: sysfs deadlock

Am Donnerstag, 15. März 2007 13:31 schrieb Hugh Dickins: > Quite apart from this mysterious "other task", I don't understand > "access" either. > > Perhaps "defer" would best capture the idea of another-task and > maybe-delay?  sysfs_defer_work(), struct sysfs_deferred_work? But we do not wish to

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Thu, 15 Mar 2007, Cornelia Huck wrote: > On Wed, 14 Mar 2007 15:23:10 -0400 (EDT), > Alan Stern <[EMAIL PROTECTED]> wrote: > > > > sysfs_work_struct is too generic; other parts of sysfs might also want to > > use workqueues for different purposes. > > > I don't like calling it "delayed"-anythi

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Wed, 14 Mar 2007 15:23:10 -0400 (EDT), Alan Stern <[EMAIL PROTECTED]> wrote: > > > +struct other_task_struct { > > > + struct kobject *kobj; > > > + void(*func)(void *); > > > + void*data; > > > + struct work_struct work; > > > +}; > > > + >

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Wed, 14 Mar 2007, Cornelia Huck wrote: > On Wed, 14 Mar 2007 12:12:37 -0400 (EDT), > Alan Stern <[EMAIL PROTECTED]> wrote: > > > This seems more elegant (not yet tested). Cornelia, does it look okay to > > you? > > Works for me (grouping & ungrouping ctc) and looks sane. Some more > comment

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Wed, 14 Mar 2007 12:12:37 -0400 (EDT), Alan Stern <[EMAIL PROTECTED]> wrote: > This seems more elegant (not yet tested). Cornelia, does it look okay to > you? Works for me (grouping & ungrouping ctc) and looks sane. Some more comments below. > +struct other_task_struct { > + struct kob

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue, 13 Mar 2007, Linus Torvalds wrote: > Could we please make this easier to use by having some common sysfs helper > routine for this kind of "delayed_store()" functionality. > > I'm not a huge fan of delayed work at all, but if we have to have it, at > least make it one generic function r

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue, 13 Mar 2007, Hugh Dickins wrote: > On Tue, 13 Mar 2007, Alan Stern wrote: > > > > On the other hand, a quick survey of the kernel source shows that > > DEVICE_ATTR is used over 1500 times. Auditing all of them is not a job > > for the faint-of-heart! > > Indeed, and faint-hearted Hugh w

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue, 13 Mar 2007, Cornelia Huck wrote: > > Another call that deadlocked with Oliver's patch is ungroup for s390 > ccwgroup devices. It can be made to work again with a similar patch. Could we please make this easier to use by having some common sysfs helper routine for this kind of "delayed

Re: 2.6.21-rc suspend regression: sysfs deadlock

On 3/13/07, Hugh Dickins <[EMAIL PROTECTED]> wrote: On Tue, 13 Mar 2007, Alan Stern wrote: > > On the other hand, a quick survey of the kernel source shows that > DEVICE_ATTR is used over 1500 times. Auditing all of them is not a job > for the faint-of-heart! Indeed, and faint-hearted Hugh wasn

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue, 13 Mar 2007, Alan Stern wrote: > > On the other hand, a quick survey of the kernel source shows that > DEVICE_ATTR is used over 1500 times. Auditing all of them is not a job > for the faint-of-heart! Indeed, and faint-hearted Hugh wasn't intending to do so: but stout-hearted Alan will ne

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue, 13 Mar 2007, Hugh Dickins wrote: > On Tue, 13 Mar 2007, Alan Stern wrote: > > > > The consensus is that we would be better off keeping Oliver's original > > patch without your silly change, and instead fixing the particular method > > call that deadlocked. Can you please try out the pa

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue, 13 Mar 2007, Alan Stern wrote: > > The consensus is that we would be better off keeping Oliver's original > patch without your silly change, and instead fixing the particular method > call that deadlocked. Can you please try out the patch below with > everything else as it was before?

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue, 13 Mar 2007 11:00:21 -0400 (EDT), Alan Stern <[EMAIL PROTECTED]> wrote: > The consensus is that we would be better off keeping Oliver's original > patch without your silly change, and instead fixing the particular method > call that deadlocked. Another call that deadlocked with Oliver's

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue. 6 Mar 2007, Hugh Dickins wrote: > But suspend to RAM still hanging, unless I "chmod a-x /usr/sbin/docker" > on SuSE 10.2: docker undock tries to unregister /sys/block/sr0 and hangs: > > 60x60 D B0415080 0 10778 10771 (NOTLB) >e8227e04 0086 e80c

Re: 2.6.21-rc suspend regression: sysfs deadlock

[For the start of this thread, see .] On Wed, 7 Mar 2007, Linus Torvalds wrote: > So you just pointed to *another* data structure that apparently violates > the "you MUST use refcounting" rule. > > What is it with you people?

Fwd: Re: 2.6.21-rc suspend regression: sysfs deadlock

To let you hear the verdict. Regards Oliver -- Weitergeleitete Nachricht -- Subject: Re: 2.6.21-rc suspend regression: sysfs deadlock Date: Mittwoch, 7. März 2007 19:02 From: Linus Torvalds <[EMAIL PROTECTED]> To: Oliver Neukum <[EMAIL PROTE

Re: 2.6.21-rc suspend regression: sysfs deadlock

Am Mittwoch, 7. März 2007 19:02 schrieb Linus Torvalds: > > On Wed, 7 Mar 2007, Oliver Neukum wrote: > > > > The problem also exists with unplugging devices. Drivers get no feedback > > to tell them when it is safe to free the data structures associated with > > an attribute. > > So you just poin

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Wed, 7 Mar 2007, Oliver Neukum wrote: > > The problem also exists with unplugging devices. Drivers get no feedback > to tell them when it is safe to free the data structures associated with > an attribute. So you just pointed to *another* data structure that apparently violates the "you MUST

Re: 2.6.21-rc suspend regression: sysfs deadlock

Am Mittwoch, 7. März 2007 17:52 schrieb Linus Torvalds: > > On Wed, 7 Mar 2007, Dmitry Torokhov wrote: > > > > ... with the exception that it will again make data associated with > > sysfs attributes accessible past the point of returning from > > sysfs_remove_file. And that was the point so driv

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Wed, 7 Mar 2007, Dmitry Torokhov wrote: > > ... with the exception that it will again make data associated with > sysfs attributes accessible past the point of returning from > sysfs_remove_file. And that was the point so drivers would not have to > care about handling access to extra data (s

Re: 2.6.21-rc suspend regression: sysfs deadlock

On 3/6/07, Linus Torvalds <[EMAIL PROTECTED]> wrote: - removing the buffer is now just mutex_lock(&inode->i_mutex); buffer = inode->i_private; inode->i_private = NULL; mutex_unlock(&inode->i_mutex); put_sysfs_buffer(buffer); - everybody is happy! ... wi

Re: 2.6.21-rc suspend regression: sysfs deadlock

Am Mittwoch, 7. März 2007 02:56 schrieb Linus Torvalds: > Anyway, I'm unable to revert the broken commit, since there are now other > changes that depend on it, but can somebody *please* do that? I'll apply > Hugh's silly patch in the meantime, just to avoid the lockup. As you like it. This patc

Re: 2.6.21-rc suspend regression: sysfs deadlock

On Tue, 6 Mar 2007, Hugh Dickins wrote: > > This comes from Oliver's commit 94bebf4d1b8e7719f0f3944c037a21cfd99a4af7 > Driver core: fix race in sysfs between sysfs_remove_file() and read()/write() > in 2.6.21-rc1. It looks to me like sysfs_write_file downs buffer->sem > while calling flush_writ

Re: 2.6.21-rc suspend regression: sysfs deadlock

Am Dienstag, 6. März 2007 20:20 schrieb Hugh Dickins: > This comes from Oliver's commit 94bebf4d1b8e7719f0f3944c037a21cfd99a4af7 > Driver core: fix race in sysfs between sysfs_remove_file() and read()/write() > in 2.6.21-rc1.  It looks to me like sysfs_write_file downs buffer->sem > while calling f