From: Roy Shterman <roy.shterman@vastdata.com>
To: anatoly.burakov@intel.com
Cc: dev@dpdk.org, yuval@vastdata.com, aviv.bendavid@vastdata.com,
Roy Shterman <roy.shterman@vastdata.com>
Subject: [dpdk-dev] [PATCH] mem: fix free segment when using huge-unlink option
Date: Mon, 22 Feb 2021 12:41:31 +0200 [thread overview]
Message-ID: <20210222104131.11979-1-roy.shterman@vastdata.com> (raw)
When using huge_unlink we unlink the segment right
after allocation. Although we unlink the file we keep
the fd in fd_list so file still exist just the path deleted.
When freeing the hugepage we need to close the fd and assign
it with (-1) in fd_list for the page to be released.
The current flow fails rte_malloc in the following flow when working
with --huge-unlink option:
1. alloc_seg() for segment A -
We allocate segment, unlink the path to the segment
and keep the file descriptor in fd_list.
2. free_seg() for segment A -
We clear the segment metadata and return - without closing fd
or assigning (-1) in fd list.
3. alloc_seg() for segment A again -
We find segment A as available, try to allocate it,
find the old fd in fd_list try to unlink it
as part of alloc_seg() but failed because path doesn't exist.
The impact of such error is falsly failing rte_malloc()
although we have hugepages available.
Fixes: d435aad37da7 ("mem: support --huge-unlink mode")
Signed-off-by: Roy Shterman <roy.shterman@vastdata.com>
---
lib/librte_eal/linux/eal_memalloc.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
diff --git a/lib/librte_eal/linux/eal_memalloc.c b/lib/librte_eal/linux/eal_memalloc.c
index 6dc1b2bae..c590d6043 100644
--- a/lib/librte_eal/linux/eal_memalloc.c
+++ b/lib/librte_eal/linux/eal_memalloc.c
@@ -709,7 +709,6 @@ free_seg(struct rte_memseg *ms, struct hugepage_info *hi,
uint64_t map_offset;
char path[PATH_MAX];
int fd, ret = 0;
- bool exit_early;
const struct internal_config *internal_conf =
eal_get_internal_configuration();
@@ -725,17 +724,8 @@ free_seg(struct rte_memseg *ms, struct hugepage_info *hi,
eal_mem_set_dump(ms->addr, ms->len, false);
- exit_early = false;
-
/* if we're using anonymous hugepages, nothing to be done */
- if (internal_conf->in_memory && !memfd_create_supported)
- exit_early = true;
-
- /* if we've already unlinked the page, nothing needs to be done */
- if (!internal_conf->in_memory && internal_conf->hugepage_unlink)
- exit_early = true;
-
- if (exit_early) {
+ if (internal_conf->in_memory && !memfd_create_supported) {
memset(ms, 0, sizeof(*ms));
return 0;
}
@@ -761,7 +751,7 @@ free_seg(struct rte_memseg *ms, struct hugepage_info *hi,
/* if we're able to take out a write lock, we're the last one
* holding onto this page.
*/
- if (!internal_conf->in_memory) {
+ if (!internal_conf->in_memory && !internal_conf->hugepage_unlink) {
ret = lock(fd, LOCK_EX);
if (ret >= 0) {
/* no one else is using this page */
--
2.24.1
next reply other threads:[~2021-02-23 8:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-22 10:41 Roy Shterman [this message]
2021-02-22 15:53 ` Burakov, Anatoly
2021-02-28 13:21 ` Roy Shterman
2021-03-01 10:44 ` Burakov, Anatoly
2021-03-25 13:34 ` [dpdk-dev] [dpdk-stable] " David Marchand
2021-04-01 11:07 ` [dpdk-dev] " Burakov, Anatoly
2021-04-07 9:09 ` David Marchand
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