Doug / smarc-fsl-linux-kernel

Download as
Browse Code ยป

Commit 0ef89d25d3e390dfa7c46772907951744a4067dc

Authored by Benjamin Herrenschmidt
Committed by Linus Torvalds
1 parent c6de002617
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

mm/hugetlb: don't crash when HPAGE_SHIFT is 0 

Some platform decide whether they support huge pages at boot time.  On
these, such as powerpc, HPAGE_SHIFT is a variable, not a constant, and is
set to 0 when there is no such support.

The patches to introduce multiple huge pages support broke that causing
the kernel to crash at boot time on machines such as POWER3 which lack
support for multiple page sizes.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Showing 1 changed file with 6 additions and 1 deletions Side-by-side Diff

... ... @@ -1283,7 +1283,12 @@
1283 1283  
1284 1284 static int __init hugetlb_init(void)
1285 1285 {
1286   - BUILD_BUG_ON(HPAGE_SHIFT == 0);
  1286 + /* Some platform decide whether they support huge pages at boot
  1287 + * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when
  1288 + * there is no such support
  1289 + */
  1290 + if (HPAGE_SHIFT == 0)
  1291 + return 0;
1287 1292  
1288 1293 if (!size_to_hstate(default_hstate_size)) {
1289 1294 default_hstate_size = HPAGE_SIZE;