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| author |   Thomas Gleixner <tglx@linutronix.de> | 2018-08-06 12:45:42 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-08-06 12:45:42 +0200 |
| commit | 9e90c7985229430428dc9ba0ec7fe422901b456d (patch) | |
| tree | cae2072feba8cc433a32d96568bbcf36070bd6e5 /mm/rmap.c | |
| parent | genirq/irqchip: Remove MULTI_IRQ_HANDLER as it's now obselete (diff) | |
| parent | irqchip/gic-v3-its: Make its_lock a raw_spin_lock_t (diff) | |
| download | wireguard-linux-9e90c7985229430428dc9ba0ec7fe422901b456d.tar.xz wireguard-linux-9e90c7985229430428dc9ba0ec7fe422901b456d.zip | |
Merge tag 'irqchip-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Pull irqchip updates from Marc Zyngier:
- GICv3 ITS LPI allocation revamp
- GICv3 support for hypervisor-enforced LPI range
- GICv3 ITS conversion to raw spinlock
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 6db729dc4c50..eb477809a5c0 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -64,6 +64,7 @@ #include <linux/backing-dev.h> #include <linux/page_idle.h> #include <linux/memremap.h> +#include <linux/userfaultfd_k.h> #include <asm/tlbflush.h> @@ -1481,11 +1482,16 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma, set_pte_at(mm, address, pvmw.pte, pteval); } - } else if (pte_unused(pteval)) { + } else if (pte_unused(pteval) && !userfaultfd_armed(vma)) { /* * The guest indicated that the page content is of no * interest anymore. Simply discard the pte, vmscan * will take care of the rest. + * A future reference will then fault in a new zero + * page. When userfaultfd is active, we must not drop + * this page though, as its main user (postcopy + * migration) will not expect userfaults on already + * copied pages. */ dec_mm_counter(mm, mm_counter(page)); /* We have to invalidate as we cleared the pte */ |