On Mon, 26 Jun 2023 15:32:40 +0200, Jaroslav Kysela wrote: > > On 26. 06. 23 15:15, Takashi Iwai wrote: > > On Mon, 26 Jun 2023 13:13:21 +0200, > > Takashi Iwai wrote: > >> > >> On Mon, 26 Jun 2023 13:09:00 +0200, > >> Jaroslav Kysela wrote: > >>> > >>> On 26. 06. 23 13:02, Takashi Iwai wrote: > >>>> On Mon, 26 Jun 2023 09:56:47 +0200, > >>>> Jaroslav Kysela wrote: > >>>>> > >>>>> On 26. 06. 23 9:33, Takashi Iwai wrote: > >>>>>> On Mon, 26 Jun 2023 09:31:18 +0200, > >>>>>> Tuo Li wrote: > >>>>>>> > >>>>>>> > >>>>>>> Hello, > >>>>>>> > >>>>>>> Thank you for your reply! > >>>>>> > >>>>>> FWIW, the simplest fix would be something like below, just extending > >>>>>> the mutex coverage. But it'll serialize the all calls, so it might > >>>>>> influence on the performance, while it's the safest way. > >>>>> > >>>>> It may be better to update total_pcm_alloc_bytes before > >>>>> snd_dma_alloc_dir_pages() call and decrease this value when allocation > >>>>> fails to allow parallel allocations. Then the mutex can be held only > >>>>> for the total_pcm_alloc_bytes variable update. > >>>> > >>>> Yes, it'd work. But a tricky part is that the actual allocation size > >>>> can be bigger, and we need to correct the total_pcm_alloc_bytes after > >>>> the allocation result. So the end result would be a patch like below, > >>>> which is a bit more complex than the previous simpler approach. But > >>>> it might be OK. > >>> > >>> The patch looks good, but it may be better to move the "post" variable > >>> updates to an inline function (mutex lock - update - mutex unlock) for > >>> a better readability. > >> > >> Sounds like a good idea. Let me cook later. > > > > ... and here it is. > > > > If that looks OK, I'll submit a proper fix patch. > > > > > > thanks, > > > > Takashi > > > > --- a/sound/core/pcm_memory.c > > +++ b/sound/core/pcm_memory.c > > @@ -31,15 +31,41 @@ static unsigned long max_alloc_per_card = 32UL * 1024UL * 1024UL; > > module_param(max_alloc_per_card, ulong, 0644); > > MODULE_PARM_DESC(max_alloc_per_card, "Max total allocation bytes per card."); > > +static void __update_allocated_size(struct snd_card *card, > > ssize_t bytes) > > Missing inline ? May be also used for > > > +static void update_allocated_size(struct snd_card *card, ssize_t bytes) > > +static void decrease_allocated_size(struct snd_card *card, size_t bytes) I left the optimizations to compilers. Usually they do inline if it makes sense, and it's often a more sensible choice. thanks, Takashi
