search for: inflate_lock

...ons, thereby resulting in a deadlock issue on OOM: fill_balloon: take balloon_lock and wait for OOM to get some memory; oom_notify: release some inflated memory via leak_balloon(); leak_balloon: wait for balloon_lock to be released by fill_balloon. This patch breaks the lock into two fine-grained inflate_lock and deflate_lock, and eliminates the unnecessary use of the shared data (i.e. vb->pnfs, vb->num_pfns). This enables leak_balloon and fill_balloon to run concurrently and solves the deadlock issue. Reported-by: Tetsuo Handa <penguin-kernel at I-love.SAKURA.ne.jp> Signed-off-by: Wei Wang...

This patch series intends to summarize the recent contributions made by Michael S. Tsirkin, Tetsuo Handa, Michal Hocko etc. via reporting and discussing the related deadlock issues on the mailinglist. Please check each patch for details. >From a high-level point of view, this patch series achieves: 1) eliminate the deadlock issue fundamentally caused by the inability to run leak_balloon and

This patch series intends to summarize the recent contributions made by Michael S. Tsirkin, Tetsuo Handa, Michal Hocko etc. via reporting and discussing the related deadlock issues on the mailinglist. Please check each patch for details. >From a high-level point of view, this patch series achieves: 1) eliminate the deadlock issue fundamentally caused by the inability to run leak_balloon and

...adlock issue on OOM: > > fill_balloon: take balloon_lock and wait for OOM to get some memory; > oom_notify: release some inflated memory via leak_balloon(); > leak_balloon: wait for balloon_lock to be released by fill_balloon. > > This patch breaks the lock into two fine-grained inflate_lock and > deflate_lock, and eliminates the unnecessary use of the shared data > (i.e. vb->pnfs, vb->num_pfns). This enables leak_balloon and > fill_balloon to run concurrently and solves the deadlock issue. > > @@ -162,20 +160,20 @@ static unsigned fill_balloon(struct virtio_ball...

...adlock issue on OOM: > > fill_balloon: take balloon_lock and wait for OOM to get some memory; > oom_notify: release some inflated memory via leak_balloon(); > leak_balloon: wait for balloon_lock to be released by fill_balloon. > > This patch breaks the lock into two fine-grained inflate_lock and > deflate_lock, and eliminates the unnecessary use of the shared data > (i.e. vb->pnfs, vb->num_pfns). This enables leak_balloon and > fill_balloon to run concurrently and solves the deadlock issue. > > @@ -162,20 +160,20 @@ static unsigned fill_balloon(struct virtio_ball...

...e); > >> if (!virtio_has_feature(vb->vdev, > >> VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > >> adjust_managed_page_count(page, -1); > >> } > >> > >> - num_allocated_pages = vb->num_pfns; > >> + mutex_lock(&vb->inflate_lock); > >> /* Did we get any? */ > >> - if (vb->num_pfns != 0) > >> - tell_host(vb, vb->inflate_vq); > >> - mutex_unlock(&vb->balloon_lock); > >> + if (num_pfns != 0) > >> + tell_host(vb, vb->inflate_vq, pfns, num_pfns); > &g...

...e); > >> if (!virtio_has_feature(vb->vdev, > >> VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) > >> adjust_managed_page_count(page, -1); > >> } > >> > >> - num_allocated_pages = vb->num_pfns; > >> + mutex_lock(&vb->inflate_lock); > >> /* Did we get any? */ > >> - if (vb->num_pfns != 0) > >> - tell_host(vb, vb->inflate_vq); > >> - mutex_unlock(&vb->balloon_lock); > >> + if (num_pfns != 0) > >> + tell_host(vb, vb->inflate_vq, pfns, num_pfns); > &g...

...adjust_managed_page_count(page, -1); } + /* + * The oom_mode is set, but we've already been able to get some + * pages, so it is time to turn it off here. + */ + if (unlikely(READ_ONCE(vb->oom_mode) && page)) + WRITE_ONCE(vb->oom_mode, false); + mutex_lock(&vb->inflate_lock); /* Did we get any? */ if (num_pfns != 0) @@ -173,6 +189,13 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) mutex_unlock(&vb->inflate_lock); atomic64_add(num_pfns, &vb->num_pages); + /* + * If oom_mode is on, return the original @num passed by + * u...

...gt;> >> fill_balloon: take balloon_lock and wait for OOM to get some memory; >> oom_notify: release some inflated memory via leak_balloon(); >> leak_balloon: wait for balloon_lock to be released by fill_balloon. >> >> This patch breaks the lock into two fine-grained inflate_lock and >> deflate_lock, and eliminates the unnecessary use of the shared data >> (i.e. vb->pnfs, vb->num_pfns). This enables leak_balloon and >> fill_balloon to run concurrently and solves the deadlock issue. >> >> @@ -162,20 +160,20 @@ static unsigned fill_balloon(...

...gt; > + /* > + * The oom_mode is set, but we've already been able to get some > + * pages, so it is time to turn it off here. > + */ > + if (unlikely(READ_ONCE(vb->oom_mode) && page)) > + WRITE_ONCE(vb->oom_mode, false); > + > mutex_lock(&vb->inflate_lock); > /* Did we get any? */ > if (num_pfns != 0) > @@ -173,6 +189,13 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > mutex_unlock(&vb->inflate_lock); > atomic64_add(num_pfns, &vb->num_pages); > > + /* > + * If oom_mode is on, r...

...gt; > + /* > + * The oom_mode is set, but we've already been able to get some > + * pages, so it is time to turn it off here. > + */ > + if (unlikely(READ_ONCE(vb->oom_mode) && page)) > + WRITE_ONCE(vb->oom_mode, false); > + > mutex_lock(&vb->inflate_lock); > /* Did we get any? */ > if (num_pfns != 0) > @@ -173,6 +189,13 @@ static unsigned fill_balloon(struct virtio_balloon *vb, size_t num) > mutex_unlock(&vb->inflate_lock); > atomic64_add(num_pfns, &vb->num_pages); > > + /* > + * If oom_mode is on, r...