Did a reply instead of reply-all. Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com> writes:
> Christophe LEROY <christophe.le...@c-s.fr> writes: > >> Le 17/01/2018 à 04:19, Aneesh Kumar K.V a écrit : >>> >>> >>> On 01/16/2018 10:18 PM, Christophe LEROY wrote: >>>> >>>> >>>> Le 16/01/2018 à 17:03, Aneesh Kumar K.V a écrit : >>>>> Christophe Leroy <christophe.le...@c-s.fr> writes: >>>>> >>>>>> An application running with libhugetlbfs fails to allocate >>>>>> additional pages to HEAP due to the hugemap being done >>>>>> inconditionally as topdown mapping: >>>>>> >>>>>> mmap(0x10080000, 1572864, PROT_READ|PROT_WRITE, >>>>>> MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0) = 0x73e80000 >>>>>> [...] >>>>>> mmap(0x74000000, 1048576, PROT_READ|PROT_WRITE, >>>>>> MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0x180000) = 0x73d80000 >>>>>> munmap(0x73d80000, 1048576) = 0 >>>>>> [...] >>>>>> mmap(0x74000000, 1572864, PROT_READ|PROT_WRITE, >>>>>> MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0x180000) = 0x73d00000 >>>>>> munmap(0x73d00000, 1572864) = 0 >>>>>> [...] >>>>>> mmap(0x74000000, 1572864, PROT_READ|PROT_WRITE, >>>>>> MAP_PRIVATE|MAP_ANONYMOUS|0x40000, -1, 0x180000) = 0x73d00000 >>>>>> munmap(0x73d00000, 1572864) = 0 >>>>>> [...] >>>>>> >>>>> >>>>> Can you explain the failure details above. I am not sure I understand >>>>> what to read from the above output. >>>> >>>> libhugetlbfs first requests an area of size 1.5Mbytes, at address >>>> 0x10080000 >>>> mmap() returns an area at address 0x73e80000 >>>> >>>> Then libhugetlbfs requests an additional area on top of that, ie at >>>> address 0x74000000, to expand the heap. >>>> But mmap() returns an area at address 0x73d80000, ie under the >>>> previous area. >>>> >>> >>> >>> Can you share the test details?. Why does it not fail on book3s64? We >>> use topdown search with book3s64. >> >> I don't know about book3s64, I only have 8xx. >> >> Here is my test app: >> > > The test ran fine on ppc64. > > kvaneesh@ltctulc6a-p1:[~]$ HUGETLB_MORECORE=yes ./a.out > 10000000-10010000 r-xp 00000000 fc:00 9044312 > /home/kvaneesh/a.out > 10010000-10020000 r--p 00000000 fc:00 9044312 > /home/kvaneesh/a.out > 10020000-10030000 rw-p 00010000 fc:00 9044312 > /home/kvaneesh/a.out > 7ffff7d60000-7ffff7f10000 r-xp 00000000 fc:00 9250090 > /lib/powerpc64le-linux-gnu/libc-2.23.so > 7ffff7f10000-7ffff7f20000 r--p 001a0000 fc:00 9250090 > /lib/powerpc64le-linux-gnu/libc-2.23.so > 7ffff7f20000-7ffff7f30000 rw-p 001b0000 fc:00 9250090 > /lib/powerpc64le-linux-gnu/libc-2.23.so > 7ffff7f40000-7ffff7f60000 r-xp 00000000 fc:00 10754812 > /usr/lib/libhugetlbfs.so.0 > 7ffff7f60000-7ffff7f70000 r--p 00010000 fc:00 10754812 > /usr/lib/libhugetlbfs.so.0 > 7ffff7f70000-7ffff7f80000 rw-p 00020000 fc:00 10754812 > /usr/lib/libhugetlbfs.so.0 > 7ffff7f80000-7ffff7fa0000 r-xp 00000000 00:00 0 > [vdso] > 7ffff7fa0000-7ffff7fe0000 r-xp 00000000 fc:00 9250107 > /lib/powerpc64le-linux-gnu/ld-2.23.so > 7ffff7fe0000-7ffff7ff0000 r--p 00030000 fc:00 9250107 > /lib/powerpc64le-linux-gnu/ld-2.23.so > 7ffff7ff0000-7ffff8000000 rw-p 00040000 fc:00 9250107 > /lib/powerpc64le-linux-gnu/ld-2.23.so > 7ffffffd0000-800000000000 rw-p 00000000 00:00 0 > [stack] > > > Allocated 1Mbytes at 0x10000000010 > > > Allocated 1Mbytes at 0x10002000020 > > > Allocated 1Mbytes at 0x10004000030 > > 10000000-10010000 r-xp 00000000 fc:00 9044312 > /home/kvaneesh/a.out > 10010000-10020000 r--p 00000000 fc:00 9044312 > /home/kvaneesh/a.out > 10020000-10030000 rw-p 00010000 fc:00 9044312 > /home/kvaneesh/a.out > 10000000000-10003000000 rw-p 00000000 00:0d 1041435 > /anon_hugepage (deleted) > 10003000000-10005000000 rw-p 03000000 00:0d 1041436 > /anon_hugepage (deleted) > 10005000000-10007000000 rw-p 05000000 00:0d 1041437 > /anon_hugepage (deleted) > 7ffff7d60000-7ffff7f10000 r-xp 00000000 fc:00 9250090 > /lib/powerpc64le-linux-gnu/libc-2.23.so > 7ffff7f10000-7ffff7f20000 r--p 001a0000 fc:00 9250090 > /lib/powerpc64le-linux-gnu/libc-2.23.so > 7ffff7f20000-7ffff7f30000 rw-p 001b0000 fc:00 9250090 > /lib/powerpc64le-linux-gnu/libc-2.23.so > 7ffff7f40000-7ffff7f60000 r-xp 00000000 fc:00 10754812 > /usr/lib/libhugetlbfs.so.0 > 7ffff7f60000-7ffff7f70000 r--p 00010000 fc:00 10754812 > /usr/lib/libhugetlbfs.so.0 > 7ffff7f70000-7ffff7f80000 rw-p 00020000 fc:00 10754812 > /usr/lib/libhugetlbfs.so.0 > 7ffff7f80000-7ffff7fa0000 r-xp 00000000 00:00 0 > [vdso] > 7ffff7fa0000-7ffff7fe0000 r-xp 00000000 fc:00 9250107 > /lib/powerpc64le-linux-gnu/ld-2.23.so > 7ffff7fe0000-7ffff7ff0000 r--p 00030000 fc:00 9250107 > /lib/powerpc64le-linux-gnu/ld-2.23.so > 7ffff7ff0000-7ffff8000000 rw-p 00040000 fc:00 9250107 > /lib/powerpc64le-linux-gnu/ld-2.23.so > 7ffffffd0000-800000000000 rw-p 00000000 00:00 0 > [stack] > > > > So i am definitely missing something. I understand that generic hugetlb > get unmapped area always search bottom up and 8xx used to depend on that > callback. But on ppc64 slice based get unmapped area always did topdown > and I am not sure whether we should change that. More over I don't think > MAP_GROWSDOWN is the right flag for selecting topdown/bottom up search. > > > Is it that libhugetlbfs does something specific for 32 bit? Other option > is to add huget_get_unmapped_area for 8xx that does bottom up search? > > If you are on ppc64 irc on freenode we can discuss this there. > -aneesh
