RE: Regression on linux-next (next-20240625)

["Borah, Chaitanya Kumar" <chaitanya.kumar.borah@intel.com>]

> -----Original Message-----
> From: Sidhartha Kumar <sidhartha.kumar@oracle.com>
> Sent: Friday, June 28, 2024 8:24 PM
> To: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com>
> Cc: Liam.Howlett@oracle.com; akpm@linux-foundation.org; linux-
> mm@kvack.org; maple-tree@lists.infradead.org; Nikula, Jani
> <jani.nikula@intel.com>; Saarinen, Jani <jani.saarinen@intel.com>; Kurmi,
> Suresh Kumar <suresh.kumar.kurmi@intel.com>; intel-
> gfx@lists.freedesktop.org
> Subject: Re: Regression on linux-next (next-20240625)
> 
> On 6/27/24 9:45 PM, Borah, Chaitanya Kumar wrote:
> > [converted to plain text]
> > +intel-gfx
> >
> > Gentle Reminder.
> >
> 
> Hello,
> 
> This patch will be dropped from mm-unstable and will not be in linux-next
> after that. I am working on a fix to include for the next version of this series.

Thank you Siddartha, We don't see the regression anymore.

Regards

Chaitanya

> 
> Thanks,
> Sid
> 
> > From: Borah, Chaitanya Kumar
> > Sent: Wednesday, June 26, 2024 8:52 PM
> > To: sidhartha.kumar@oracle.com
> > Cc: Liam.Howlett@oracle.com; akpm@linux-foundation.org;
> > linux-mm@kvack.org; maple-tree@lists.infradead.org; Nikula, Jani
> > <jani.nikula@intel.com>; Saarinen, Jani <jani.saarinen@intel.com>;
> > Kurmi, Suresh Kumar <Suresh.Kumar.Kurmi@intel.com>
> > Subject: Regression on linux-next (next-20240625)
> >
> > Hello Sidhartha,
> >
> > Hope you are doing well. I am Chaitanya from the linux graphics team in
> Intel.
> >
> > This mail is regarding a regression we are seeing in our CI runs[1] on linux-
> next repository.
> >
> > Since the version next-20240625 [2], we are seeing the following
> > regression
> >
> > ``````````````````````````````````````````````````````````````````````
> > ``````````` <3>[    2.336948] BUG: sleeping function called from
> > invalid context at include/linux/sched/mm.h:337 <3>[    2.336974]
> > in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 95, name:
> > kdevtmpfs <3>[    2.336989] preempt_count: 1, expected: 0 <3>[
> > 2.336998] RCU nest depth: 0, expected: 0 <4>[    2.337006] 3 locks
> > held by kdevtmpfs/95:
> > <4>[    2.337015]  #0: ffff888100d2c3f0 (sb_writers){.+.+}-{0:0}, at:
> > filename_create+0x5d/0x160 <4>[    2.337041]  #1: ffff888100800840
> > (&type->i_mutex_dir_key/1){+.+.}-{3:3}, at: filename_create+0x9d/0x160
> > <4>[    2.337065]  #2: ffff888100800658 (&simple_offset_lock_class){+.+.}-
> {2:2}, at: mtree_alloc_cyclic+0x71/0xf0 <3>[    2.337089] Preemption disabled
> at:
> > <3>[    2.337091] [<0000000000000000>] 0x0 <4>[    2.337105] CPU: 13
> > UID: 0 PID: 95 Comm: kdevtmpfs Not tainted
> > 6.10.0-rc5-next-20240625-next-20240625-g0fc4bfab2cd4+ #1 <4>[
> > 2.337126] Hardware name: ASUS System Product Name/PRIME Z790-P WIFI,
> BIOS 0812 02/24/2023 <4>[    2.337141] Call Trace:
> > <4>[    2.337147]  <TASK>
> > <4>[    2.337152]  dump_stack_lvl+0xb0/0xd0 <4>[    2.337163]
> > __might_resched+0x194/0x2b0 <4>[    2.337175]
> > kmem_cache_alloc_noprof+0x20c/0x280
> > <4>[    2.337186]  ? mas_alloc_nodes+0x173/0x230 <4>[    2.337197]
> > mas_alloc_nodes+0x173/0x230 <4>[    2.337207]
> > mas_alloc_cyclic+0x27b/0x550 <4>[    2.337220]
> > mtree_alloc_cyclic+0x92/0xf0
> > ``````````````````````````````````````````````````````````````````````
> > ```````````
> > Details log can be found in [3].
> >
> > After bisecting the tree, the following patch [4] seems to be the first "bad"
> > commit
> >
> > ``````````````````````````````````````````````````````````````````````
> > ```````````````````````````````````
> >      maple_tree: remove mas_destroy() from mas_nomem()
> >
> >      Separate call to mas_destroy() from mas_nomem() so we can check
> > for no
> >      memory errors without destroying the current maple state in
> >      mas_store_gfp().  We then add calls to mas_destroy() to callers
> > of
> >      mas_nomem().
> >
> >      Link:
> > https://lkml.kernel.org/r/20240618204750.79512-6-sidhartha.kumar@oracl
> > e.com
> >      Signed-off-by: Sidhartha Kumar mailto:sidhartha.kumar@oracle.com
> >
> > ``````````````````````````````````````````````````````````````````````
> > ```````````````````````````````````
> >
> > We could not revert the patch because of merge conflicts but resetting to
> the parent of the commit seems to fix the issue.
> >
> > Could you please check why the patch causes this regression and provide a
> fix if necessary?
> >
> > Thank you.
> >
> > Regards
> >
> > Chaitanya
> >
> > [1] https://intel-gfx-ci.01.org/tree/linux-next/combined-alt.html?
> > [2]
> > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/co
> > mmit/?h=next-20240625 [3]
> > https://intel-gfx-ci.01.org/tree/linux-next/next-20240625/bat-rpls-4/b
> > oot0.txt [4]
> > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/co
> > mmit/?id=187827d2dc3749d66546696b78584ee4c54687b0