* Re: [dpdk-stable] [dpdk-dev] [PATCH] vhost: fix race condition in fdset_add [not found] ` <1fa47f8c-18a1-fbb4-1794-3324126cf9f1@redhat.com> @ 2018-12-14 10:07 ` Matthias Gatto 2018-12-14 10:08 ` Maxime Coquelin 0 siblings, 1 reply; 2+ messages in thread From: Matthias Gatto @ 2018-12-14 10:07 UTC (permalink / raw) To: maxime.coquelin; +Cc: dev, tiwei.bie, zhihong.wang, stable On Fri, Dec 14, 2018 at 10:53 AM Maxime Coquelin <maxime.coquelin@redhat.com> wrote: > > > > On 12/14/18 10:51 AM, Maxime Coquelin wrote: > > > > > > On 12/14/18 10:32 AM, Matthias Gatto wrote: > >> On Tue, Dec 11, 2018 at 7:11 PM Maxime Coquelin > >> <maxime.coquelin@redhat.com> wrote: > >>> > >>> Hi Matthias, > >>> > >>> On 12/6/18 5:00 PM, Matthias Gatto wrote: > >>>> fdset_add can call fdset_shrink_nolock which call fdset_move > >>>> concurrently to poll that is call in fdset_event_dispatch. > >>>> > >>>> This patch add a mutex to protect poll from been call at the same time > >>>> fdset_add call fdset_shrink_nolock. > >>>> > >>>> Signed-off-by: Matthias Gatto <matthias.gatto@outscale.com> > >>>> --- > >>>> lib/librte_vhost/fd_man.c | 4 ++++ > >>>> lib/librte_vhost/fd_man.h | 1 + > >>>> lib/librte_vhost/socket.c | 1 + > >>>> 3 files changed, 6 insertions(+) > >>>> > >>>> diff --git a/lib/librte_vhost/fd_man.c b/lib/librte_vhost/fd_man.c > >>>> index 38347ab..55d4856 100644 > >>>> --- a/lib/librte_vhost/fd_man.c > >>>> +++ b/lib/librte_vhost/fd_man.c > >>>> @@ -129,7 +129,9 @@ > >>>> pthread_mutex_lock(&pfdset->fd_mutex); > >>>> i = pfdset->num < MAX_FDS ? pfdset->num++ : -1; > >>>> if (i == -1) { > >>>> + pthread_mutex_lock(&pfdset->fd_pooling_mutex); > >>>> fdset_shrink_nolock(pfdset); > >>>> + pthread_mutex_unlock(&pfdset->fd_pooling_mutex); > >>>> i = pfdset->num < MAX_FDS ? pfdset->num++ : -1; > >>>> if (i == -1) { > >>>> pthread_mutex_unlock(&pfdset->fd_mutex); > >>>> @@ -246,7 +248,9 @@ > >>>> numfds = pfdset->num; > >>>> pthread_mutex_unlock(&pfdset->fd_mutex); > >>>> > >>>> + pthread_mutex_lock(&pfdset->fd_pooling_mutex); > >>>> val = poll(pfdset->rwfds, numfds, 1000 /* millisecs */); > >>>> + pthread_mutex_unlock(&pfdset->fd_pooling_mutex); > >>> > >>> Any reason we cannot use the existing fd_mutex? > >> > >> yes, using the existing fd_mutex would block fdset_add during the > >> polling in > >> fdset_event_dispatch. > >> > >> here fd_pooling_mutex block only fdset_shrink_nolock inside > >> fdset_add which happen only in very rare occasions. > > > > > > Thanks for the clarification: > > > > Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com> > > I guess we need to cc: stable, can you help with specifying which > commit it fixes? > > Thanks in advance, > Maxime > this commit 1b815b89599cdd9b54e5aa70f5b97088225b2bcc which was actually a commit I've made, sorry for that. Thanks for the review, Matthias > > Maxime ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [dpdk-stable] [dpdk-dev] [PATCH] vhost: fix race condition in fdset_add 2018-12-14 10:07 ` [dpdk-stable] [dpdk-dev] [PATCH] vhost: fix race condition in fdset_add Matthias Gatto @ 2018-12-14 10:08 ` Maxime Coquelin 0 siblings, 0 replies; 2+ messages in thread From: Maxime Coquelin @ 2018-12-14 10:08 UTC (permalink / raw) To: Matthias Gatto; +Cc: dev, tiwei.bie, zhihong.wang, stable On 12/14/18 11:07 AM, Matthias Gatto wrote: > On Fri, Dec 14, 2018 at 10:53 AM Maxime Coquelin > <maxime.coquelin@redhat.com> wrote: >> >> >> >> On 12/14/18 10:51 AM, Maxime Coquelin wrote: >>> >>> >>> On 12/14/18 10:32 AM, Matthias Gatto wrote: >>>> On Tue, Dec 11, 2018 at 7:11 PM Maxime Coquelin >>>> <maxime.coquelin@redhat.com> wrote: >>>>> >>>>> Hi Matthias, >>>>> >>>>> On 12/6/18 5:00 PM, Matthias Gatto wrote: >>>>>> fdset_add can call fdset_shrink_nolock which call fdset_move >>>>>> concurrently to poll that is call in fdset_event_dispatch. >>>>>> >>>>>> This patch add a mutex to protect poll from been call at the same time >>>>>> fdset_add call fdset_shrink_nolock. >>>>>> >>>>>> Signed-off-by: Matthias Gatto <matthias.gatto@outscale.com> >>>>>> --- >>>>>> lib/librte_vhost/fd_man.c | 4 ++++ >>>>>> lib/librte_vhost/fd_man.h | 1 + >>>>>> lib/librte_vhost/socket.c | 1 + >>>>>> 3 files changed, 6 insertions(+) >>>>>> >>>>>> diff --git a/lib/librte_vhost/fd_man.c b/lib/librte_vhost/fd_man.c >>>>>> index 38347ab..55d4856 100644 >>>>>> --- a/lib/librte_vhost/fd_man.c >>>>>> +++ b/lib/librte_vhost/fd_man.c >>>>>> @@ -129,7 +129,9 @@ >>>>>> pthread_mutex_lock(&pfdset->fd_mutex); >>>>>> i = pfdset->num < MAX_FDS ? pfdset->num++ : -1; >>>>>> if (i == -1) { >>>>>> + pthread_mutex_lock(&pfdset->fd_pooling_mutex); >>>>>> fdset_shrink_nolock(pfdset); >>>>>> + pthread_mutex_unlock(&pfdset->fd_pooling_mutex); >>>>>> i = pfdset->num < MAX_FDS ? pfdset->num++ : -1; >>>>>> if (i == -1) { >>>>>> pthread_mutex_unlock(&pfdset->fd_mutex); >>>>>> @@ -246,7 +248,9 @@ >>>>>> numfds = pfdset->num; >>>>>> pthread_mutex_unlock(&pfdset->fd_mutex); >>>>>> >>>>>> + pthread_mutex_lock(&pfdset->fd_pooling_mutex); >>>>>> val = poll(pfdset->rwfds, numfds, 1000 /* millisecs */); >>>>>> + pthread_mutex_unlock(&pfdset->fd_pooling_mutex); >>>>> >>>>> Any reason we cannot use the existing fd_mutex? >>>> >>>> yes, using the existing fd_mutex would block fdset_add during the >>>> polling in >>>> fdset_event_dispatch. >>>> >>>> here fd_pooling_mutex block only fdset_shrink_nolock inside >>>> fdset_add which happen only in very rare occasions. >>> >>> >>> Thanks for the clarification: >>> >>> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com> >> >> I guess we need to cc: stable, can you help with specifying which >> commit it fixes? >> >> Thanks in advance, >> Maxime >> > > this commit 1b815b89599cdd9b54e5aa70f5b97088225b2bcc > which was actually a commit I've made, sorry for that. Don't be sorry, your contributions are welcome! I'll fixup the commit message with adding Fixes line. Thanks, Maxime > Thanks for the review, > > Matthias >>> Maxime ^ permalink raw reply [flat|nested] 2+ messages in thread
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2018-12-14 10:07 ` [dpdk-stable] [dpdk-dev] [PATCH] vhost: fix race condition in fdset_add Matthias Gatto
2018-12-14 10:08 ` Maxime Coquelin
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