Commit a364092a412975e506415f77f0628cbdd28c3913
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82cbc11a41
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raid: make RAID autodetect default a KConfig option
RAID autodetect has the side effect of requiring synchronisation of all device drivers, which can make the boot several seconds longer (I've measured 7 on one of my laptops).... even for systems that don't have RAID setup for the root filesystem (the only FS where this matters). This patch makes the default for autodetect a config option; either way the user can always override via the kernel command line. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: NeilBrown <neilb@suse.de>
Showing 2 changed files with 23 additions and 2 deletions Side-by-side Diff
drivers/md/Kconfig
| ... | ... | @@ -30,6 +30,20 @@ |
| 30 | 30 | |
| 31 | 31 | If unsure, say N. |
| 32 | 32 | |
| 33 | +config MD_AUTODETECT | |
| 34 | + bool "Autodetect RAID arrays during kernel boot" | |
| 35 | + depends on BLK_DEV_MD | |
| 36 | + default y | |
| 37 | + ---help--- | |
| 38 | + If you say Y here, then the kernel will try to autodetect raid | |
| 39 | + arrays as part of its boot process. | |
| 40 | + | |
| 41 | + If you don't use raid and say Y, this autodetection can cause | |
| 42 | + a several-second delay in the boot time due to various | |
| 43 | + synchronisation steps that are part of this step. | |
| 44 | + | |
| 45 | + If unsure, say Y. | |
| 46 | + | |
| 33 | 47 | config MD_LINEAR |
| 34 | 48 | tristate "Linear (append) mode" |
| 35 | 49 | depends on BLK_DEV_MD |
init/do_mounts_md.c
| ... | ... | @@ -12,7 +12,12 @@ |
| 12 | 12 | * The code for that is here. |
| 13 | 13 | */ |
| 14 | 14 | |
| 15 | -static int __initdata raid_noautodetect, raid_autopart; | |
| 15 | +#ifdef CONFIG_MD_AUTODETECT | |
| 16 | +static int __initdata raid_noautodetect; | |
| 17 | +#else | |
| 18 | +static int __initdata raid_noautodetect=1; | |
| 19 | +#endif | |
| 20 | +static int __initdata raid_autopart; | |
| 16 | 21 | |
| 17 | 22 | static struct { |
| 18 | 23 | int minor; |
| ... | ... | @@ -252,6 +257,8 @@ |
| 252 | 257 | |
| 253 | 258 | if (!strncmp(str, "noautodetect", wlen)) |
| 254 | 259 | raid_noautodetect = 1; |
| 260 | + if (!strncmp(str, "autodetect", wlen)) | |
| 261 | + raid_noautodetect = 0; | |
| 255 | 262 | if (strncmp(str, "partitionable", wlen)==0) |
| 256 | 263 | raid_autopart = 1; |
| 257 | 264 | if (strncmp(str, "part", wlen)==0) |
| ... | ... | @@ -288,7 +295,7 @@ |
| 288 | 295 | create_dev("/dev/md0", MKDEV(MD_MAJOR, 0)); |
| 289 | 296 | |
| 290 | 297 | if (raid_noautodetect) |
| 291 | - printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=noautodetect)\n"); | |
| 298 | + printk(KERN_INFO "md: Skipping autodetection of RAID arrays. (raid=autodetect will force)\n"); | |
| 292 | 299 | else |
| 293 | 300 | autodetect_raid(); |
| 294 | 301 | md_setup_drive(); |