/* * hugepage-shm: * * Example of using huge page memory in a user application using Sys V shared * memory system calls. In this example the app is requesting 256MB of * memory that is backed by huge pages. The application uses the flag * SHM_HUGETLB in the shmget system call to inform the kernel that it is * requesting huge pages. * * For the ia64 architecture, the Linux kernel reserves Region number 4 for * huge pages. That means that if one requires a fixed address, a huge page * aligned address starting with 0x800000... will be required. If a fixed * address is not required, the kernel will select an address in the proper * range. * Other architectures, such as ppc64, i386 or x86_64 are not so constrained. * * Note: The default shared memory limit is quite low on many kernels, * you may need to increase it via: * * echo 268435456 > /proc/sys/kernel/shmmax * * This will increase the maximum size per shared memory segment to 256MB. * The other limit that you will hit eventually is shmall which is the * total amount of shared memory in pages. To set it to 16GB on a system * with a 4kB pagesize do: * * echo 4194304 > /proc/sys/kernel/shmall */ #include #include #include #include #include #include #ifndef SHM_HUGETLB #define SHM_HUGETLB 04000 #endif #define LENGTH (256UL*1024*1024) #define dprintf(x) printf(x) /* Only ia64 requires this */ #ifdef __ia64__ #define ADDR (void *)(0x8000000000000000UL) #define SHMAT_FLAGS (SHM_RND) #else #define ADDR (void *)(0x0UL) #define SHMAT_FLAGS (0) #endif int main(void) { int shmid; unsigned long i; char *shmaddr; shmid = shmget(2, LENGTH, SHM_HUGETLB | IPC_CREAT | SHM_R | SHM_W); if (shmid < 0) { perror("shmget"); exit(1); } printf("shmid: 0x%x\n", shmid); shmaddr = shmat(shmid, ADDR, SHMAT_FLAGS); if (shmaddr == (char *)-1) { perror("Shared memory attach failure"); shmctl(shmid, IPC_RMID, NULL); exit(2); } printf("shmaddr: %p\n", shmaddr); dprintf("Starting the writes:\n"); for (i = 0; i < LENGTH; i++) { shmaddr[i] = (char)(i); if (!(i % (1024 * 1024))) dprintf("."); } dprintf("\n"); dprintf("Starting the Check..."); for (i = 0; i < LENGTH; i++) if (shmaddr[i] != (char)i) { printf("\nIndex %lu mismatched\n", i); exit(3); } dprintf("Done.\n"); if (shmdt((const void *)shmaddr) != 0) { perror("Detach failure"); shmctl(shmid, IPC_RMID, NULL); exit(4); } shmctl(shmid, IPC_RMID, NULL); return 0; } class='txt' type='search' size='10' name='q' value=''/>
path: root/sound/soc/codecs/wm8997.c
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authorJerome Brunet <jbrunet@baylibre.com>2017-01-20 08:20:24 -0800
committerArnd Bergmann <arnd@arndb.de>2017-01-27 16:46:42 +0100
commitfeb3cbea0946c67060e2d5bcb7499b0a6f6700fe (patch)
tree4789978854a7fd97de08f4b77f220bcd9278417b /sound/soc/codecs/wm8997.c
parent7a308bb3016f57e5be11a677d15b821536419d36 (diff)
ARM64: dts: meson-gxbb-odroidc2: fix GbE tx link breakage
OdroidC2 GbE link breaks under heavy tx transfer. This happens even if the MAC does not enable Energy Efficient Ethernet (No Low Power state Idle on the Tx path). The problem seems to come from the phy Rx path, entering the LPI state. Disabling EEE advertisement on the phy prevent this feature to be negociated with the link partner and solve the issue. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Signed-off-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'sound/soc/codecs/wm8997.c')