Re: [PATCH 2/2] fs, elf: drop MAP_FIXED usage from elf_map

[Michal Hocko]

On Tue 29-05-18 15:21:14, Mike Kravetz wrote:
> Just a quick heads up.  I noticed a change in libhugetlbfs testing starting
> with v4.17-rc1.
> 
> V4.16 libhugetlbfs test results
> ********** TEST SUMMARY
> *                      2M            
> *                      32-bit 64-bit 
> *     Total testcases:   110    113   
> *             Skipped:     0      0   
> *                PASS:   105    111   
> *                FAIL:     0      0   
> *    Killed by signal:     4      1   
> *   Bad configuration:     1      1   
> *       Expected FAIL:     0      0   
> *     Unexpected PASS:     0      0   
> *    Test not present:     0      0   
> * Strange test result:     0      0   
> **********
> 
> v4.17-rc1 (and later) libhugetlbfs test results
> ********** TEST SUMMARY
> *                      2M            
> *                      32-bit 64-bit 
> *     Total testcases:   110    113   
> *             Skipped:     0      0   
> *                PASS:    98    111   
> *                FAIL:     0      0   
> *    Killed by signal:    11      1   
> *   Bad configuration:     1      1   
> *       Expected FAIL:     0      0   
> *     Unexpected PASS:     0      0   
> *    Test not present:     0      0   
> * Strange test result:     0      0   
> **********
> 
> I traced the 7 additional (32-bit) killed by signal results to this
> commit 4ed28639519c fs, elf: drop MAP_FIXED usage from elf_map.
> 
> libhugetlbfs does unusual things and even provides custom linker scripts.
> So, in hindsight this change in behavior does not seem too unexpected.  I
> JUST discovered this while running libhugetlbfs tests for an unrelated
> issue/change and, will do some analysis to see exactly what is happening.

I am definitely interested about further details. Are there any messages
in the kernel log?

-- 
Michal Hocko
SUSE Labs