Re: Regression from 2.6.36

From: Andrew Morton
Date: Thu Apr 14 2011 - 01:26:18 EST


On Thu, 14 Apr 2011 04:10:58 +0200 Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote:

> > --- a/fs/file.c~a
> > +++ a/fs/file.c
> > @@ -39,14 +39,17 @@ int sysctl_nr_open_max = 1024 * 1024; /*
> > */
> > static DEFINE_PER_CPU(struct fdtable_defer, fdtable_defer_list);
> >
> > -static inline void *alloc_fdmem(unsigned int size)
> > +static void *alloc_fdmem(unsigned int size)
> > {
> > - void *data;
> > -
> > - data = kmalloc(size, GFP_KERNEL|__GFP_NOWARN);
> > - if (data != NULL)
> > - return data;
> > -
> > + /*
> > + * Very large allocations can stress page reclaim, so fall back to
> > + * vmalloc() if the allocation size will be considered "large" by the VM.
> > + */
> > + if (size <= (PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER) {
> > + void *data = kmalloc(size, GFP_KERNEL|__GFP_NOWARN);
> > + if (data != NULL)
> > + return data;
> > + }
> > return vmalloc(size);
> > }
> >
> > _
> >
>
> Acked-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
>
> #define PAGE_ALLOC_COSTLY_ORDER 3
>
> On x86_64, this means we try kmalloc() up to 4096 files in fdtable.

Thanks. I added the cc:stable to the changelog.

It'd be nice to get this tested if poss, to confrm that it actually
fixes things.

Also, Melpoke.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/