From: Rafal Jaworowski <raj@semihalf.com>
To: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@ozlabs.org
Subject: Re: [PATCH v3 1/4] powerpc: Introduce local (non-broadcast) forms of tlb invalidates
Date: Thu, 04 Sep 2008 21:17:13 +0200 [thread overview]
Message-ID: <48C03439.1000301@semihalf.com> (raw)
In-Reply-To: <1220465344-16753-1-git-send-email-galak@kernel.crashing.org>
Kumar Gala wrote:
[...]
> The intent of this change is to handle SMP based invalidates via IPIs instead
> of broadcasts as the mechanism scales better for larger number of cores.
Hi Kumar,
How is the inter-IPI deadlock avoidance designed in this new approach? I don't
know the close details of low-level Book-E VM design in Linux, but am thinking
about a scenario when we have two TLB misses hitting almost immediately on two
different cores and they both want to send a TLB invalidate IPI to each other.
How do you manage this?
The reason I ask is we had similar considerations (and problems) when bringing
SMP to the dual core e500 on FreeBSD and ended up not using IPIs, at least for
now, because of such concerns (and actual problems of this kind).
Rafal
next prev parent reply other threads:[~2008-09-04 19:30 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-03 18:09 [PATCH v3 1/4] powerpc: Introduce local (non-broadcast) forms of tlb invalidates Kumar Gala
2008-09-03 18:09 ` [PATCH v3 2/4] powerpc: Fixes for CONFIG_PTE_64BIT for SMP support Kumar Gala
2008-09-03 18:09 ` [PATCH v3 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading " Kumar Gala
2008-09-03 18:09 ` [PATCH v3 4/4] powerpc/mm: Implement _PAGE_SPECIAL & pte_special() for 32-bit Kumar Gala
2008-09-04 3:15 ` Benjamin Herrenschmidt
2008-09-04 3:14 ` [PATCH v3 3/4] powerpc/fsl-booke: Fixup 64-bit PTE reading for SMP support Benjamin Herrenschmidt
2008-09-04 3:12 ` [PATCH v3 2/4] powerpc: Fixes for CONFIG_PTE_64BIT " Benjamin Herrenschmidt
2008-09-05 19:44 ` Kumar Gala
2008-09-05 22:38 ` Benjamin Herrenschmidt
2008-09-06 15:32 ` Kumar Gala
2008-09-04 19:17 ` Rafal Jaworowski [this message]
2008-09-04 21:30 ` [PATCH v3 1/4] powerpc: Introduce local (non-broadcast) forms of tlb invalidates Benjamin Herrenschmidt
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