On 12/09/15 at 10:38am, Herbert Xu wrote:
> On Wed, Dec 09, 2015 at 03:36:32AM +0100, Thomas Graf wrote:
> >
> > Without knowing your exact implementation plans: introducing an
> > additional reference indirection for every lookup will have a
> > huge performance penalty as well.
> >
> > Is your
On Wed, Dec 09, 2015 at 03:36:32AM +0100, Thomas Graf wrote:
>
> Without knowing your exact implementation plans: introducing an
> additional reference indirection for every lookup will have a
> huge performance penalty as well.
>
> Is your plan to only introduce the master table after an
> alloc
On 12/09/15 at 10:24am, Herbert Xu wrote:
> On Wed, Dec 09, 2015 at 03:18:26AM +0100, Thomas Graf wrote:
> >
> > Assuming that we only encounter this scenario with very large
> > table sizes, it might be OK to assume that deferring the actual
> > resize via the worker thread while continuing to in
On Wed, Dec 09, 2015 at 03:18:26AM +0100, Thomas Graf wrote:
>
> Assuming that we only encounter this scenario with very large
> table sizes, it might be OK to assume that deferring the actual
> resize via the worker thread while continuing to insert above
> 100% utilization in atomic context is s
On 12/05/15 at 03:06pm, Herbert Xu wrote:
> Unless we can make __vmalloc work with BH disabled, I guess we'll
> have to go back to multi-level lookups unless someone has a better
> suggestion.
Assuming that we only encounter this scenario with very large
table sizes, it might be OK to assume that
From: Thomas Graf
Date: Mon, 7 Dec 2015 16:35:24 +0100
> Did you look into what __vmalloc prevents to work with BH disabled?
You can't issue the cross-cpu TLB flushes from atomic contexts.
It's the kernel page table updates that create the restriction.
--
To unsubscribe from this list: send the
On 12/05/15 at 03:06pm, Herbert Xu wrote:
> On Fri, Dec 04, 2015 at 07:15:55PM +0100, Phil Sutter wrote:
> >
> > > Only one should really do this, while others are waiting.
> >
> > Sure, that was my previous understanding of how this thing works.
>
> Yes that's clearly how it should be. Unfortun
From: Herbert Xu
Date: Sat, 5 Dec 2015 15:03:54 +0800
> Sorry Dave but you'll have to revert this because I've been able
> to trigger the following crash with the patch:
>
> Testing concurrent rhashtable access from 50 threads
> [ cut here ]
> kernel BUG at ../mm/vmalloc.
On Fri, Dec 04, 2015 at 07:15:55PM +0100, Phil Sutter wrote:
>
> > Only one should really do this, while others are waiting.
>
> Sure, that was my previous understanding of how this thing works.
Yes that's clearly how it should be. Unfortunately while adding
the locking to do this, I found out t
On Fri, Dec 04, 2015 at 04:53:34PM -0500, David Miller wrote:
> From: Herbert Xu
> Date: Fri, 4 Dec 2015 22:39:56 +0800
>
> > When an rhashtable user pounds rhashtable hard with back-to-back
> > insertions we may end up growing the table in GFP_ATOMIC context.
> > Unfortunately when the table rea
From: Herbert Xu
Date: Fri, 4 Dec 2015 22:39:56 +0800
> When an rhashtable user pounds rhashtable hard with back-to-back
> insertions we may end up growing the table in GFP_ATOMIC context.
> Unfortunately when the table reaches a certain size this often
> fails because we don't have enough physic
On Fri, Dec 04, 2015 at 09:45:20AM -0800, Eric Dumazet wrote:
> On Fri, 2015-12-04 at 18:01 +0100, Phil Sutter wrote:
> > On Fri, Dec 04, 2015 at 10:39:56PM +0800, Herbert Xu wrote:
> > > On Thu, Dec 03, 2015 at 08:08:39AM -0800, Eric Dumazet wrote:
> > > >
> > > > Anyway, __vmalloc() can be used w
On Fri, 2015-12-04 at 18:01 +0100, Phil Sutter wrote:
> On Fri, Dec 04, 2015 at 10:39:56PM +0800, Herbert Xu wrote:
> > On Thu, Dec 03, 2015 at 08:08:39AM -0800, Eric Dumazet wrote:
> > >
> > > Anyway, __vmalloc() can be used with GFP_ATOMIC, have you tried this ?
> >
> > OK I've tried it and I no
On Fri, Dec 04, 2015 at 10:39:56PM +0800, Herbert Xu wrote:
> On Thu, Dec 03, 2015 at 08:08:39AM -0800, Eric Dumazet wrote:
> >
> > Anyway, __vmalloc() can be used with GFP_ATOMIC, have you tried this ?
>
> OK I've tried it and I no longer get any ENOMEM errors!
I can't confirm this, sadly. Using
On Thu, Dec 03, 2015 at 08:08:39AM -0800, Eric Dumazet wrote:
>
> Anyway, __vmalloc() can be used with GFP_ATOMIC, have you tried this ?
OK I've tried it and I no longer get any ENOMEM errors!
---8<---
When an rhashtable user pounds rhashtable hard with back-to-back
insertions we may end up growi
15 matches
Mail list logo
