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17 May 2024, 11:00:25 UTC
Revision d7c53c9e822a4fefa13a0cae76f3190bfd0d5c11 authored by Borislav Petkov on 19 August 2010, 18:10:29 UTC, committed by H. Peter Anvin on 19 August 2010, 21:47:43 UTC 
x86, hotplug: Serialize CPU hotplug to avoid bringup concurrency issues
 
When testing cpu hotplug code on 32-bit we kept hitting the "CPU%d:
Stuck ??" message due to multiple cores concurrently accessing the
cpu_callin_mask, among others.

Since these codepaths are not protected from concurrent access due to
the fact that there's no sane reason for making an already complex
code unnecessarily more complex - we hit the issue only when insanely
switching cores off- and online - serialize hotplugging cores on the
sysfs level and be done with it.

[ v2.1: fix !HOTPLUG_CPU build ]

Cc: <stable@kernel.org>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
LKML-Reference: <20100819181029.GC17171@aftab>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
1 parent 8848a91
Raw File
Tip revision: d7c53c9e822a4fefa13a0cae76f3190bfd0d5c11 authored by Borislav Petkov on 19 August 2010, 18:10:29 UTC
x86, hotplug: Serialize CPU hotplug to avoid bringup concurrency issues
Tip revision: d7c53c9
bin2c.c 
/*
 * Unloved program to convert a binary on stdin to a C include on stdout
 *
 * Jan 1999 Matt Mackall <mpm@selenic.com>
 *
 * This software may be used and distributed according to the terms
 * of the GNU General Public License, incorporated herein by reference.
 */

#include <stdio.h>

int main(int argc, char *argv[])
{
	int ch, total=0;

	if (argc > 1)
		printf("const char %s[] %s=\n",
			argv[1], argc > 2 ? argv[2] : "");

	do {
		printf("\t\"");
		while ((ch = getchar()) != EOF)
		{
			total++;
			printf("\\x%02x",ch);
			if (total % 16 == 0)
				break;
		}
		printf("\"\n");
	} while (ch != EOF);

	if (argc > 1)
		printf("\t;\n\nconst int %s_size = %d;\n", argv[1], total);

	return 0;
}
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