Messages in this thread | | | Date | Fri, 1 Sep 2017 09:47:56 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [patch-rt] drivers/zram: fix zcomp_stream_get() smp_processor_id() use in preemptible code |
| |
On Fri, 1 Sep 2017, Sebastian Andrzej Siewior wrote:
> 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.
Fair enough.
| |