From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Tiwei Bie <tiwei.bie@intel.com>
Cc: dev@dpdk.org, przemyslawx.lal@intel.com,
kuralamudhan.ramakrishnan@intel.com, ivan.coughlan@intel.com,
ray.kinsella@intel.com
Subject: Re: [dpdk-dev] [PATCH 19.02 2/2] mem: use memfd for no-huge mode
Date: Wed, 28 Nov 2018 09:11:23 +0000 [thread overview]
Message-ID: <fb918fa2-4e2f-a67e-e1b2-2ddd98a64a8b@intel.com> (raw)
In-Reply-To: <20181128045753.GA26256@debian>
On 28-Nov-18 4:57 AM, Tiwei Bie wrote:
> On Tue, Nov 13, 2018 at 05:54:48PM +0000, Anatoly Burakov wrote:
>> When running in no-huge mode, we anonymously allocate our memory.
>> While this works for regular NICs and vdev's, it's not suitable
>> for memory sharing scenarios such as virtio with vhost_user
>> backend.
>>
>> To fix this, allocate no-huge memory using memfd, and register
>> it with memalloc just like any other memseg fd. This will enable
>> using rte_memseg_get_fd() API with --no-huge EAL flag.
>>
>> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
>> ---
>> lib/librte_eal/linuxapp/eal/eal_memory.c | 46 ++++++++++++++++++++++--
>> 1 file changed, 44 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/librte_eal/linuxapp/eal/eal_memory.c b/lib/librte_eal/linuxapp/eal/eal_memory.c
>> index 48b23ce19..8feac2c56 100644
>> --- a/lib/librte_eal/linuxapp/eal/eal_memory.c
>> +++ b/lib/librte_eal/linuxapp/eal/eal_memory.c
>> @@ -25,6 +25,7 @@
>> #include <sys/time.h>
>> #include <signal.h>
>> #include <setjmp.h>
>> +#include <linux/memfd.h>
>> #ifdef RTE_EAL_NUMA_AWARE_HUGEPAGES
>> #include <numa.h>
>> #include <numaif.h>
>> @@ -1345,12 +1346,15 @@ eal_legacy_hugepage_init(void)
>> /* hugetlbfs can be disabled */
>> if (internal_config.no_hugetlbfs) {
>> struct rte_memseg_list *msl;
>> + int n_segs, cur_seg, fd, memfd, flags;
>> uint64_t page_sz;
>> - int n_segs, cur_seg;
>>
>> /* nohuge mode is legacy mode */
>> internal_config.legacy_mem = 1;
>>
>> + /* nohuge mode is single-file segments mode */
>> + internal_config.single_file_segments = 1;
>> +
>> /* create a memseg list */
>> msl = &mcfg->memsegs[0];
>>
>> @@ -1363,8 +1367,36 @@ eal_legacy_hugepage_init(void)
>> return -1;
>> }
>>
>> + /* set up parameters for anonymous mmap */
>> + fd = -1;
>> + flags = MAP_PRIVATE | MAP_ANONYMOUS;
>> +
>> + /* create a memfd and store it in the segment fd table */
>> + memfd = memfd_create("nohuge", 0);
>> + if (memfd < 0) {
>> + RTE_LOG(ERR, EAL, "Cannot create memfd: %s\n",
>> + strerror(errno));
>> + RTE_LOG(ERR, EAL, "Falling back to anonymous map\n");
>> + } else {
>> + /* we got an fd - now resize it */
>> + if (ftruncate(memfd, internal_config.memory) < 0) {
>> + RTE_LOG(ERR, EAL, "Cannot resize memfd: %s\n",
>> + strerror(errno));
>> + RTE_LOG(ERR, EAL, "Falling back to anonymous map\n");
>> + close(memfd);
>> + } else {
>> + /* creating memfd-backed file was successful.
>> + * we want changes to memfd to be visible to
>> + * other processes (such as vhost backend), so
>> + * map it as shared memory.
>> + */
>> + RTE_LOG(DEBUG, EAL, "Using memfd for anonymous memory\n");
>> + fd = memfd;
>> + flags = MAP_SHARED;
>> + }
>> + }
>> addr = mmap(NULL, internal_config.memory, PROT_READ | PROT_WRITE,
>> - MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
>> + flags, fd, 0);
>> if (addr == MAP_FAILED) {
>> RTE_LOG(ERR, EAL, "%s: mmap() failed: %s\n", __func__,
>> strerror(errno));
>> @@ -1375,6 +1407,16 @@ eal_legacy_hugepage_init(void)
>> msl->socket_id = 0;
>> msl->len = internal_config.memory;
>>
>> + /* we're in single-file segments mode, so only the segment list
>> + * fd needs to be set up.
>> + */
>> + if (fd != -1) {
>> + if (eal_memalloc_set_seg_list_fd(0, fd) < 0) {
>> + RTE_LOG(ERR, EAL, "Cannot set up segment list fd\n");
>> + /* not a serious error, proceed */
>> + }
>> + }
>
> Hi Anatoly,
>
> Thanks for the work!
>
> It seems the support for getting fd offset is missing in no-huge
> mode. I got below error in virtio-user while trying this series
> with --no-huge:
>
> update_memory_region(): Failed to get offset, ms=0x10002e000 rte_errno=19
That's weird, it should have been working. I'll look into it, thanks!
>
> Thanks
>
>> +
>> /* populate memsegs. each memseg is one page long */
>> for (cur_seg = 0; cur_seg < n_segs; cur_seg++) {
>> arr = &msl->memseg_arr;
>> --
>> 2.17.1
>
--
Thanks,
Anatoly
next prev parent reply other threads:[~2018-11-28 9:11 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-13 17:54 [dpdk-dev] [PATCH 19.02 0/2] Allow using virtio without hugepages Anatoly Burakov
2018-11-13 17:54 ` [dpdk-dev] [PATCH 19.02 1/2] memalloc: allow setting up segment list fd's Anatoly Burakov
2018-11-13 17:54 ` [dpdk-dev] [PATCH 19.02 2/2] mem: use memfd for no-huge mode Anatoly Burakov
2018-11-28 4:57 ` Tiwei Bie
2018-11-28 9:11 ` Burakov, Anatoly [this message]
2018-12-11 16:43 ` [dpdk-dev] [PATCH v2 0/5] Allow using virtio without hugepages Anatoly Burakov
2018-12-13 4:53 ` Tiwei Bie
2018-12-13 11:43 ` [dpdk-dev] [PATCH v3 0/5] Allow using virtio-user " Anatoly Burakov
2018-12-20 22:01 ` Thomas Monjalon
2018-12-13 11:43 ` [dpdk-dev] [PATCH v3 1/5] mem: fix error code for segment fd API for external segs Anatoly Burakov
2018-12-14 9:15 ` Maxime Coquelin
2018-12-13 11:43 ` [dpdk-dev] [PATCH v3 2/5] memalloc: check for memfd support in segment fd API Anatoly Burakov
2018-12-14 9:19 ` Maxime Coquelin
2018-12-13 11:43 ` [dpdk-dev] [PATCH v3 3/5] memalloc: allow setting up segment list fd's Anatoly Burakov
2018-12-14 10:03 ` Maxime Coquelin
2018-12-13 11:43 ` [dpdk-dev] [PATCH v3 4/5] mem: use memfd for no-huge mode Anatoly Burakov
2018-12-13 11:59 ` Burakov, Anatoly
2018-12-14 10:06 ` Maxime Coquelin
2018-12-13 11:43 ` [dpdk-dev] [PATCH v3 5/5] test: add segment fd API test Anatoly Burakov
2018-12-14 10:09 ` Maxime Coquelin
2018-12-11 16:43 ` [dpdk-dev] [PATCH v2 1/5] mem: fix error code for segment fd API for external segs Anatoly Burakov
2018-12-11 16:43 ` [dpdk-dev] [PATCH v2 2/5] memalloc: check for memfd support in segment fd API Anatoly Burakov
2018-12-11 16:43 ` [dpdk-dev] [PATCH v2 3/5] memalloc: allow setting up segment list fd's Anatoly Burakov
2018-12-11 16:43 ` [dpdk-dev] [PATCH v2 4/5] mem: use memfd for no-huge mode Anatoly Burakov
2018-12-13 4:59 ` Tiwei Bie
2018-12-13 11:36 ` Burakov, Anatoly
2018-12-11 16:43 ` [dpdk-dev] [PATCH v2 5/5] test: add segment fd API test Anatoly Burakov
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