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vcl: store libc_epfd in vls instead of vcl

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ldp stores the libc epfds it uses in conjunction with vcl epfds in vcl
attributes. Apart from being an ldp, as opposed to vcl, specific
attribute, the epfd is retrieved on session close with vls locks that
could be acquired from multiple threads.

Avoid grabbing locks when retrieving the attribute.

Type: improvement

Signed-off-by: Florin Coras <fcoras@cisco.com>
Change-Id: I5fc52d72667a7693b1557d209c3890a968422f1e
This commit is contained in:
Florin Coras 2024-11-26 00:29:24 -08:00 committed by Dave Barach
parent 3628353e09
commit 978d48b765
6 changed files with 59 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
src/vcl/ldp.c
View File

@ -327,19 +327,17 @@ close (int fd)
vlsh = ldp_fd_to_vlsh (fd);
if (vlsh != VLS_INVALID_HANDLE)
{
epfd = vls_attr (vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
epfd = vls_get_libc_epfd (vlsh);
if (epfd > 0)
{
ldp_worker_ctx_t *ldpw = ldp_worker_get_current ();
u32 size = sizeof (epfd);
LDBG (0, "fd %d: calling libc_close: epfd %u", fd, epfd);
libc_close (epfd);
ldpw->mq_epfd_added = 0;
epfd = 0;
(void) vls_attr (vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &epfd, &size);
vls_set_libc_epfd (vlsh, 0);
}
else if (PREDICT_FALSE (epfd < 0))
{
@ -2460,9 +2458,8 @@ epoll_ctl (int epfd, int op, int fd, struct epoll_event *event)
else
{
int libc_epfd;
u32 size = sizeof (epfd);
libc_epfd = vls_attr (vep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
libc_epfd = vls_get_libc_epfd (vep_vlsh);
if (!libc_epfd)
{
LDBG (1, "epfd %d, vep_vlsh %d calling libc_epoll_create1: "
@ -2475,8 +2472,7 @@ epoll_ctl (int epfd, int op, int fd, struct epoll_event *event)
goto done;
}
rv = vls_attr (vep_vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &libc_epfd,
&size);
rv = vls_set_libc_epfd (vep_vlsh, libc_epfd);
if (rv < 0)
{
errno = -rv;
@ -2538,7 +2534,7 @@ ldp_epoll_pwait (int epfd, struct epoll_event *events, int maxevents,
time_to_wait = ((timeout >= 0) ? (double) timeout / 1000 : 0);
max_time = clib_time_now (&ldpw->clib_time) + time_to_wait;
libc_epfd = vls_attr (ep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
libc_epfd = vls_get_libc_epfd (ep_vlsh);
if (PREDICT_FALSE (libc_epfd < 0))
{
errno = -libc_epfd;
@ -2616,11 +2612,9 @@ ldp_epoll_pwait_eventfd (int epfd, struct epoll_event *events,
return -1;
}
libc_epfd = vls_attr (ep_vlsh, VPPCOM_ATTR_GET_LIBC_EPFD, 0, 0);
libc_epfd = vls_get_libc_epfd (ep_vlsh);
if (PREDICT_FALSE (!libc_epfd))
{
u32 size = sizeof (epfd);
LDBG (1, "epfd %d, vep_vlsh %d calling libc_epoll_create1: "
"EPOLL_CLOEXEC", epfd, ep_vlsh);
libc_epfd = libc_epoll_create1 (EPOLL_CLOEXEC);
@ -2630,7 +2624,7 @@ ldp_epoll_pwait_eventfd (int epfd, struct epoll_event *events,
goto done;
}
rv = vls_attr (ep_vlsh, VPPCOM_ATTR_SET_LIBC_EPFD, &libc_epfd, &size);
rv = vls_set_libc_epfd (ep_vlsh, libc_epfd);
if (rv < 0)
{
errno = -rv;

47
src/vcl/vcl_locked.c
View File

@ -103,6 +103,7 @@ typedef struct vcl_locked_session_
u32 shared_data_index; /**< shared data index if any */
u32 owner_vcl_wrk_index; /**< vcl wrk of the vls wrk at alloc */
uword *vcl_wrk_index_to_session_index; /**< map vcl wrk to session */
int libc_epfd; /**< epoll fd for libc epoll */
} vcl_locked_session_t;
typedef struct vls_worker_
@ -2028,6 +2029,52 @@ vls_use_real_epoll (void)
return vcl_worker_get_current ()->vcl_needs_real_epoll;
}
int
vls_set_libc_epfd (vls_handle_t ep_vlsh, int libc_epfd)
{
vcl_locked_session_t *vls;
vls_mt_detect ();
if (!(vls = vls_get_w_dlock (ep_vlsh)))
return VPPCOM_EBADFD;
if (vls_mt_session_should_migrate (vls))
{
vls = vls_mt_session_migrate (vls);
if (PREDICT_FALSE (!vls))
return VPPCOM_EBADFD;
}
vls->libc_epfd = libc_epfd;
vls_unlock (vls);
vls_mt_pool_runlock ();
return 0;
}
int
vls_get_libc_epfd (vls_handle_t ep_vlsh)
{
vcl_locked_session_t *vls;
int rv;
vls_mt_detect ();
vls_mt_pool_rlock ();
vls = vls_get (ep_vlsh);
if (!vls)
{
vls_mt_pool_runlock ();
return VPPCOM_EBADFD;
}
/* Avoid locking. In mt scenarios, one thread might be blocking waiting on
* the fd while another might be closing it. While closing, this attribute
* might be retrieved, so avoid deadlock */
rv = vls->libc_epfd;
vls_mt_pool_runlock ();
return rv;
}
void
vls_register_vcl_worker (void)
{

2
src/vcl/vcl_locked.h
View File

@ -56,6 +56,8 @@ int vls_app_create (char *app_name);
unsigned char vls_use_eventfd (void);
unsigned char vls_mt_wrk_supported (void);
int vls_use_real_epoll (void);
int vls_set_libc_epfd (vls_handle_t ep_vlsh, int libc_epfd);
int vls_get_libc_epfd (vls_handle_t ep_vlsh);
void vls_register_vcl_worker (void);
#endif /* SRC_VCL_VCL_LOCKED_H_ */

3
src/vcl/vcl_private.h
View File

@ -163,9 +163,8 @@ typedef struct vcl_session_
session_handle_t parent_handle;
u32 listener_index; /**< index of parent listener (if any) */
int n_accepted_sessions; /**< sessions accepted by this listener */
vppcom_epoll_t vep;
vppcom_epoll_t vep; /**< epoll context */
u32 attributes; /**< see @ref vppcom_session_attr_t */
int libc_epfd;
u32 vrf;
u16 gso_size;

19
src/vcl/vppcom.c
View File

@ -3893,25 +3893,6 @@ vppcom_session_attr (uint32_t session_handle, uint32_t op,
rv = VPPCOM_EINVAL;
break;
case VPPCOM_ATTR_GET_LIBC_EPFD:
rv = session->libc_epfd;
VDBG (2, "VPPCOM_ATTR_GET_LIBC_EPFD: libc_epfd %d", rv);
break;
case VPPCOM_ATTR_SET_LIBC_EPFD:
if (PREDICT_TRUE (buffer && buflen &&
(*buflen == sizeof (session->libc_epfd))))
{
session->libc_epfd = *(int *) buffer;
*buflen = sizeof (session->libc_epfd);
VDBG (2, "VPPCOM_ATTR_SET_LIBC_EPFD: libc_epfd %d, buflen %d",
session->libc_epfd, *buflen);
}
else
rv = VPPCOM_EINVAL;
break;
case VPPCOM_ATTR_GET_PROTOCOL:
if (buffer && buflen && (*buflen >= sizeof (int)))
{

4
src/vcl/vppcom.h
View File

@ -148,8 +148,8 @@ typedef enum
VPPCOM_ATTR_GET_LCL_ADDR,
VPPCOM_ATTR_SET_LCL_ADDR,
VPPCOM_ATTR_GET_PEER_ADDR,
VPPCOM_ATTR_GET_LIBC_EPFD,
VPPCOM_ATTR_SET_LIBC_EPFD,
VPPCOM_ATTR_GET_UNUSED,
VPPCOM_ATTR_SET_UNUSED,
VPPCOM_ATTR_GET_PROTOCOL,
VPPCOM_ATTR_GET_LISTEN,
VPPCOM_ATTR_GET_ERROR,