From: Daniel J Blueman <daniel@numascale.com>
To: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Bjorn Helgaas <bhelgaas@google.com>
Cc: Daniel J Blueman <daniel@numascale.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org, Steffen Persvold <sp@numascale.com>
Subject: [PATCH v4 2/4] Numachip: Elide self-IPI ICR polling
Date: Tue, 4 Nov 2014 16:29:42 +0800 [thread overview]
Message-ID: <1415089784-28779-2-git-send-email-daniel@numascale.com> (raw)
In-Reply-To: <1415089784-28779-1-git-send-email-daniel@numascale.com>
The default self-IPI path polls the ICR to delay sending the IPI until
there is no IPI in progress. This is redundant on x86-86 APICs, since
IPIs are queued. See the AMD64 Architecture Programmer's Manual, vol 2,
p525.
Signed-off-by: Daniel J Blueman <daniel@numascale.com>
---
apic_numachip.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index 81d70ba..bd083c0 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -145,7 +145,7 @@ static void numachip_send_IPI_all(int vector)
static void numachip_send_IPI_self(int vector)
{
- __default_send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
+ apic_write(APIC_SELF_IPI, vector);
}
static int __init numachip_probe(void)
--
1.9.1
next prev parent reply other threads:[~2014-11-04 8:31 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-04 8:29 [PATCH v4 1/4] Numachip: Fix 16-bit APIC ID truncation Daniel J Blueman
2014-11-04 8:29 ` Daniel J Blueman [this message]
2014-11-04 8:29 ` [PATCH v4 3/4] Numachip: APIC driver cleanups Daniel J Blueman
2014-11-04 8:29 ` [PATCH v4 4/4] Use 2GB memory block size on large-memory x86-64 systems Daniel J Blueman
2015-08-21 18:19 ` Luck, Tony
2015-08-21 18:38 ` Yinghai Lu
2015-08-21 20:27 ` Luck, Tony
2015-08-21 20:50 ` Yinghai Lu
2015-08-21 23:54 ` Tony Luck
2015-08-24 17:46 ` Yinghai Lu
2015-08-24 20:41 ` Tony Luck
2015-08-24 21:25 ` Yinghai Lu
2015-08-24 22:39 ` Tony Luck
2015-08-24 23:41 ` Yinghai Lu
2015-08-24 23:59 ` Yinghai Lu
[not found] ` <CA+8MBbKur4SLh-7EKhU16_ra7gbvnOARg-ZWScJWH9q1hKufZQ@mail.gmail.com>
2015-08-25 19:01 ` Yinghai Lu
2015-08-25 22:06 ` Tony Luck
2015-08-26 4:17 ` Ingo Molnar
2015-08-26 5:42 ` Yinghai Lu
2015-08-26 20:49 ` Andrew Morton
2015-08-26 21:15 ` Yinghai Lu
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