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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH] powerpc/64: interrupt return in C
Date: Sun, 08 Sep 2019 20:50:42 +1000	[thread overview]
Message-ID: <1567938684.jsvbj3jz78.astroid@bobo.none> (raw)
In-Reply-To: <20190828090606.5028-1-npiggin@gmail.com>

Nicholas Piggin's on August 28, 2019 7:06 pm:
> This is a work in progress that goes on top of the syscalls in C patch.
> It's not quite complete, 64e low level exit is not taken care of, and
> the new return is hacked into the existing interrupt handlers pretty
> quickly (e.g., full gprs handling is still ugly and could be cleaned),

In performance testing on a POWER9, page fault latency is about 1.1%
faster with interrupt returns in C which always saves NVGPRs. So I
think the plan will be to rip out all the NVGPR save optimisation from
the 64-bit code.

Thanks,
Nick

      parent reply	other threads:[~2019-09-08 10:54 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-28  9:06 [PATCH] powerpc/64: interrupt return in C Nicholas Piggin
2019-08-28  9:28 ` Christophe Leroy
2019-08-28 11:56   ` Nicholas Piggin
2019-09-08 10:50 ` Nicholas Piggin [this message]

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