linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au
Cc: linuxppc-dev@lists.ozlabs.org,
	"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: [PATCH V2] powerpc: Don't do runtime futex_cmpxchg test
Date: Mon, 26 Feb 2018 19:39:50 +0530	[thread overview]
Message-ID: <20180226140950.12111-1-aneesh.kumar@linux.vnet.ibm.com> (raw)

futex_detect_cmpxchg() does a cmpxchg_futex_value_locked on a NULL user addr to
runtime detect whether architecture implements atomic cmpxchg for futex. POWER
do implement the feature and hence we can enable the config instead of depending
on runtime detection.

We could possible enable this on everything. For now limitted to book3s_64

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/Kconfig.cputype | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index a429d859f15d..31bc2bd5dfd1 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -75,6 +75,7 @@ config PPC_BOOK3S_64
 	select ARCH_SUPPORTS_NUMA_BALANCING
 	select IRQ_WORK
 	select HAVE_KERNEL_XZ
+	select HAVE_FUTEX_CMPXCHG if FUTEX
 
 config PPC_BOOK3E_64
 	bool "Embedded processors"
-- 
2.14.3

             reply	other threads:[~2018-02-26 14:10 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-02-26 14:09 Aneesh Kumar K.V [this message]
2018-02-26 22:16 ` [PATCH V2] powerpc: Don't do runtime futex_cmpxchg test Nicholas Piggin
2018-02-27  4:00   ` Aneesh Kumar K.V
2018-02-28 10:44 ` Michael Ellerman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180226140950.12111-1-aneesh.kumar@linux.vnet.ibm.com \
    --to=aneesh.kumar@linux.vnet.ibm.com \
    --cc=benh@kernel.crashing.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mpe@ellerman.id.au \
    --cc=paulus@samba.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).