Re: [patch-rt] drivers/zram: fix zcomp_stream_get() smp_processor_id() use in preemptible code

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2017-08-31 21:32:30 [+0200], Thomas Gleixner wrote:
> > zram_lock_table() is bit_spin_lock() on !RT and spin_lock(&table->lock);
> > on RT. So this is done.
> > !RT has this running in a kmap_atomic() section so they have no
> > preemption there.
> > zcomp_stream_get() returns a per-CPU object which is protected with a
> > spinlock and only accessed locked.
> 
> So when we are inside a spinlocked section, why is this_cpu_ptr() not
> working? That does not make sense.

zram_decompress_page() invokes zcomp_stream_get() within a spin_lock
section (zram_lock_table()). This is fine.
zram_bvec_write() does not invoke zcomp_stream_get() within a spin_lock
section.

> Thanks,
> 
> 	tglx

Sebastian
--
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [RT Stable]     [Kernel Newbies]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]

  Powered by Linux