Bug 143472
| Summary: | hugetlb mmap failed in compatibility mode in em64t | ||||||||||
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| Product: | Red Hat Enterprise Linux 4 | Reporter: | Racing Guo <racing.guo> | ||||||||
| Component: | kernel | Assignee: | Jason Baron <jbaron> | ||||||||
| Status: | CLOSED ERRATA | QA Contact: | |||||||||
| Severity: | medium | Docs Contact: | |||||||||
| Priority: | medium | ||||||||||
| Version: | 4.0 | CC: | davej, jbaron, kenneth.w.chen, knoel, racing.guo, yanmin.zhang | ||||||||
| Target Milestone: | --- | ||||||||||
| Target Release: | --- | ||||||||||
| Hardware: | x86_64 | ||||||||||
| OS: | Linux | ||||||||||
| Whiteboard: | |||||||||||
| Fixed In Version: | Doc Type: | Bug Fix | |||||||||
| Doc Text: | Story Points: | --- | |||||||||
| Clone Of: | Environment: | ||||||||||
| Last Closed: | 2005-06-08 15:13:14 UTC | Type: | --- | ||||||||
| Regression: | --- | Mount Type: | --- | ||||||||
| Documentation: | --- | CRM: | |||||||||
| Verified Versions: | Category: | --- | |||||||||
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |||||||||
| Cloudforms Team: | --- | Target Upstream Version: | |||||||||
| Embargoed: | |||||||||||
| Attachments: |
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Description
Racing Guo
2004-12-21 11:29:05 UTC
Created attachment 108937 [details]
test case to reproduce bug
so it seems like we need the following patch: --- linux-2.6.9/include/asm-x86_64/page.h.bak Wed Dec 22 15:33:35 2004 +++ linux-2.6.9/include/asm-x86_64/page.h Wed Dec 22 15:34:56 2004 @@ -24,10 +24,13 @@ #define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1)) #define LARGE_PAGE_SIZE (1UL << PMD_SHIFT) +#ifdef CONFIG_HUGETLB_PAGE #define HPAGE_SHIFT PMD_SHIFT #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT) #define HPAGE_MASK (~(HPAGE_SIZE - 1)) #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) +#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA +#endif #ifdef __KERNEL__ #ifndef __ASSEMBLY__ i'll build a test kernel with that patch This bug still exists in RHEL4-RC Has the above patch been tested? If not, i'll build a kernel for us to test. thanks. Yes. It works. But we didn't see this patch has been integrated into RHEL4-RC. If we apply the patch at comment 2, another bug will be triggered. hugetlb_get_unmapped_area_topdown in file arch/i386/mm/hugetlbpage.c might cause vma overflow out of 4GB address space of IA32 processes on x86_64. Then, the third bug will be triggered that a memory leak will happen when the IA32 process exit because kernel just releases the page table below 4GB. I will add the test case and a patch to fix these bugs. Created attachment 110234 [details] The test case to show the unmapped area overflow beyond 4GB for IA32 processes Reproduce it: 1) Apply the patch of comment 2 to kernel; 2) #mkdir /root/test/mmap/ 3) #echo "100">/proc/sys/vm/nr_hugepages 4) #mount -t hugetlbfs none /root/test/mmap 5) #gcc -o test4 -m32 test4.c 6) #./test4 7) #cat /proc/test4_pid/maps If we delete the getchar() in test4.c and use '#while true; do ./test4; done' to execute test4 looply, the memory will be used up soon. Created attachment 110235 [details] The patch to fix these bugs Pls. don't apply the patch of comment #2 before applying rhel4-rc-hugetlb_mmap_fail2.patch.diff. rhel4-rc-hugetlb_mmap_fail2.patch.diff includes the patch of comment #2. Ok. thanks. I don't see this patch posted to upstream? I guess its not upstream b/c flexmap isn't there for x86_64 This bug still exists in RHEL4 An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on the solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHSA-2005-420.html |