From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>,
Michael Neuling <mikey@neuling.org>,
Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Subject: [PATCH v3 2/3] powerpc/64s/idle: avoid POWER9 DD1 and DD2.0 ERAT workaround on DD2.1
Date: Fri, 3 Nov 2017 15:13:20 +1100 [thread overview]
Message-ID: <20171103041321.5113-3-npiggin@gmail.com> (raw)
In-Reply-To: <20171103041321.5113-1-npiggin@gmail.com>
DD2.1 does not have to flush the ERAT after a state-loss idle.
Performance testing was done on a DD2.1 using only the stop0 idle state
(the shallowest state which supports state loss), using context_switch
selftest configured to ping-poing between two threads on the same core
and two different cores.
Performance improvement for same core is 7.0%, different cores is 14.8%.
Reviewed-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
arch/powerpc/kernel/idle_book3s.S | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 175d49f468af..d77766814090 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -542,7 +542,9 @@ pnv_restore_hyp_resource_arch300:
* then clear bit 60 in MMCRA to ensure the PMU starts running.
*/
blt cr3,1f
+BEGIN_FTR_SECTION
PPC_INVALIDATE_ERAT
+END_FTR_SECTION_IFSET(CPU_FTR_POWER9_DD1 | CPU_FTR_POWER9_DD20)
ld r1,PACAR1(r13)
mfspr r4,SPRN_MMCRA
ori r4,r4,(1 << (63-60))
--
2.15.0
next prev parent reply other threads:[~2017-11-03 4:13 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-03 4:13 [PATCH v3 0/3] Add POWER9 DD2.0 feature, remove idle workarounds in DD2.1 Nicholas Piggin
2017-11-03 4:13 ` [PATCH v3 1/3] powerpc: add POWER9_DD20 feature Nicholas Piggin
2017-11-07 23:30 ` [v3,1/3] " Michael Ellerman
2017-11-03 4:13 ` Nicholas Piggin [this message]
2017-11-03 4:13 ` [PATCH v3 3/3] powerpc/64s/idle: avoid POWER9 DD1 and DD2.0 PMU workaround on DD2.1 Nicholas Piggin
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=20171103041321.5113-3-npiggin@gmail.com \
--to=npiggin@gmail.com \
--cc=linuxppc-dev@lists.ozlabs.org \
--cc=mikey@neuling.org \
--cc=svaidy@linux.vnet.ibm.com \
/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).