Re: test13-pre3

From: Maciej W. Rozycki (macro@ds2.pg.gda.pl)
Date: Mon Dec 18 2000 - 07:58:59 EST

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Hi,

What is this change about?

diff -u --recursive --new-file v2.4.0-test12/linux/arch/i386/kernel/smpboot.c linux/arch/i386/kernel/smpboot.c
--- v2.4.0-test12/linux/arch/i386/kernel/smpboot.c Mon Dec 11 17:59:43 2000
+++ linux/arch/i386/kernel/smpboot.c Thu Dec 14 14:54:40 2000
@@ -694,6 +694,11 @@
                 apic_write_around(APIC_ICR, APIC_DM_STARTUP
                                         | (start_eip >> 12));

+ /*
+ * Give the other CPU some time to accept the IPI.
+ */
+ udelay(300);
+
                 Dprintk("Startup point 1.\n");

                 Dprintk("Waiting for send to finish...\n");

There is the following code is just after it, making the above change
just useless garbage:

                timeout = 0;
                do {
                        Dprintk("+");
                        udelay(100);
                        send_status = apic_read(APIC_ICR) & APIC_ICR_BUSY;
                } while (send_status && (timeout++ < 1000));

                /*
                 * Give the other CPU some time to accept the IPI.
                 */
                udelay(200);

If we need 600usecs of delay for certain systems, then why not just make
it like below?

Maciej

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@ds2.pg.gda.pl, PGP key available        +
patch-2.0.4-test13-pre3-startup_ipi-0
diff -up --recursive --new-file linux-2.4.0-test13-pre3.macro/arch/i386/kernel/smpboot.c linux-2.4.0-test13-pre3/arch/i386/kernel/smpboot.c
--- linux-2.4.0-test13-pre3.macro/arch/i386/kernel/smpboot.c	Mon Dec 18 12:14:10 2000
+++ linux-2.4.0-test13-pre3/arch/i386/kernel/smpboot.c	Mon Dec 18 12:15:49 2000
@@ -694,11 +694,6 @@ static void __init do_boot_cpu (int apic
 		apic_write_around(APIC_ICR, APIC_DM_STARTUP
 					| (start_eip >> 12));
 
-		/*
-		 * Give the other CPU some time to accept the IPI.
-		 */
-		udelay(300);
-
 		Dprintk("Startup point 1.\n");
 
 		Dprintk("Waiting for send to finish...\n");
@@ -712,7 +707,7 @@ static void __init do_boot_cpu (int apic
 		/*
 		 * Give the other CPU some time to accept the IPI.
 		 */
-		udelay(200);
+		udelay(500);
 		/*
 		 * Due to the Pentium erratum 3AP.
 		 */
-
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Next message: Martin Diehl: "[PATCH] yenta, pm - part 2"
Previous message: Holger Kiehl: "Why is LINK_MAX so low?"
In reply to: Linus Torvalds: "test13-pre3"
Next in thread: Christoph Rohland: "Re: test13-pre3"
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