[PATCH] Support for hugetlb backed shared memory

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/HOWTO b/HOWTO
index a5caea3db7a6201d74311b50a5d5d56bbbb77311..6ac744cd3d436124f8474ff135c7a842fb92136b 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -357,6 +357,8 @@ mem=str             Fio can use various types of memory as the io unit buffer.
                        shm     Use shared memory as the buffers. Allocated
                                through shmget(2).
 
+                       shmhuge Same as shm, but use huge pages as backing.
+
                        mmap    Use anonymous memory maps as the buffers.
                                Allocated through mmap(2).
 

diff --git a/fio.c b/fio.c
index 3ffe1e17a601eebc54debbb1f51580a969b56bc1..87136141b0e34770851dbab53a942d9774eb6f48 100644 (file)
--- a/fio.c
+++ b/fio.c
@@ -507,7 +507,12 @@ static int init_io_u(struct thread_data *td)
                max_units = td->iodepth;
 
        max_bs = max(td->max_bs[DDIR_READ], td->max_bs[DDIR_WRITE]);
-       td->orig_buffer_size = max_bs * max_units + MASK;
+       td->orig_buffer_size = max_bs * max_units;
+
+       if (td->mem_type == MEM_SHMHUGE)
+               td->orig_buffer_size = (td->orig_buffer_size + FIO_HUGE_PAGE - 1) & ~FIO_HUGE_PAGE;
+       else
+               td->orig_buffer_size += MASK;
 
        if (allocate_io_mem(td))
                return 1;

diff --git a/fio.h b/fio.h
index f0b4e6a1d72630c64f4768fe99da6b64527ef730..c4facfbe995b2f0ed20e88353fb645a528721ec9 100644 (file)
--- a/fio.h
+++ b/fio.h
@@ -123,6 +123,7 @@ struct group_run_stats {
 enum fio_memtype {
        MEM_MALLOC = 0, /* ordinary malloc */
        MEM_SHM,        /* use shared memory segments */
+       MEM_SHMHUGE,    /* use shared memory segments with huge pages */
        MEM_MMAP,       /* use anonynomous mmap */
 };
 

diff --git a/init.c b/init.c
index ae960302f70a5695b08854198776a6553f1a609b..bfe698106b3bf02fe529990c19aa204267ef273b 100644 (file)
--- a/init.c
+++ b/init.c
@@ -833,9 +833,17 @@ static int str_mem_cb(void *data, const char *mem)
        } else if (!strncmp(mem, "mmap", 4)) {
                td->mem_type = MEM_MMAP;
                return 0;
+       } else if (!strncmp(mem, "shmhuge", 7)) {
+#ifdef FIO_HAVE_HUGETLB
+               td->mem_type = MEM_SHMHUGE;
+               return 0;
+#else
+               log_err("fio: shmhuge not available\n");
+               return 1;
+#endif
        }
 
-       log_err("fio: mem type: malloc, shm, mmap\n");
+       log_err("fio: mem type: malloc, shm, mmap, shmhuge\n");
        return 1;
 }
 

diff --git a/memory.c b/memory.c
index 39dc250c52ba052800eeea1ed9815282b427a006..a7bf82a88fbafd276be899e769e29348c1682757 100644 (file)
--- a/memory.c
+++ b/memory.c
@@ -61,8 +61,13 @@ int allocate_io_mem(struct thread_data *td)
 {
        if (td->mem_type == MEM_MALLOC)
                td->orig_buffer = malloc(td->orig_buffer_size);
-       else if (td->mem_type == MEM_SHM) {
-               td->shm_id = shmget(IPC_PRIVATE, td->orig_buffer_size, IPC_CREAT | 0600);
+       else if (td->mem_type == MEM_SHM || td->mem_type == MEM_SHMHUGE) {
+               int flags = IPC_CREAT | SHM_R | SHM_W;
+
+               if (td->mem_type == MEM_SHMHUGE)
+                       flags |= SHM_HUGETLB;
+
+               td->shm_id = shmget(IPC_PRIVATE, td->orig_buffer_size, flags);
                if (td->shm_id < 0) {
                        td_verror(td, errno);
                        perror("shmget");

diff --git a/os-linux.h b/os-linux.h
index 752d17e1e84db3af75726560574aaa20b712a8e1..e456ebcaea22204ffbcbf562377e8f6b6312d16c 100644 (file)
--- a/os-linux.h
+++ b/os-linux.h
@@ -18,6 +18,7 @@
 #define FIO_HAVE_SPLICE
 #define FIO_HAVE_IOSCHED_SWITCH
 #define FIO_HAVE_ODIRECT
+#define FIO_HAVE_HUGETLB
 
 #define OS_MAP_ANON            (MAP_ANONYMOUS)
 

diff --git a/os.h b/os.h
index b44d34c6b5ef07dea4c5c7fe2c05be09c5abbe9e..b5f43e593e6251efb179dc2dd22ca1ecdb59e3e3 100644 (file)
--- a/os.h
+++ b/os.h
@@ -47,4 +47,11 @@
 #define OS_O_DIRECT                    O_DIRECT
 #endif
 
+#ifndef FIO_HAVE_HUGETLB
+#define SHM_HUGETLB                    0
+#define FIO_HUGE_PAGE                  0
+#else
+#define FIO_HUGE_PAGE                  (2048 * 1024)
+#endif
+
 #endif