From: Davidlohr Bueso <d...@stgolabs.net> Both register and unregister call build_map_info() in order to create the list of mappings before installing or removing breakpoints for every mm which maps file backed memory. As such, there is no reason to hold the i_mmap_rwsem exclusively, so share it and allow concurrent readers to build the mapping data.
Signed-off-by: Davidlohr Bueso <dbu...@suse.de> Acked-by: Srikar Dronamraju <sri...@linux.vnet.ibm.com> Acked-by: "Kirill A. Shutemov" <kir...@shutemov.name> Cc: Oleg Nesterov <o...@redhat.com> Acked-by: Hugh Dickins <hu...@google.com> Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Rik van Riel <r...@redhat.com> Acked-by: Mel Gorman <mgor...@suse.de> Signed-off-by: Andrew Morton <a...@linux-foundation.org> Signed-off-by: Linus Torvalds <torva...@linux-foundation.org> https://jira.sw.ru/browse/PSBM-122663 (cherry picked from commit 4a23717a236b2ab31efb1651f586126789fc997f) Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- kernel/events/uprobes.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 9f312227a769..be501d8d9704 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -690,7 +690,7 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register) int more = 0; again: - i_mmap_lock_write(mapping); + i_mmap_lock_read(mapping); vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { if (!valid_vma(vma, is_register)) continue; @@ -721,7 +721,7 @@ build_map_info(struct address_space *mapping, loff_t offset, bool is_register) info->mm = vma->vm_mm; info->vaddr = offset_to_vaddr(vma, offset); } - i_mmap_unlock_write(mapping); + i_mmap_unlock_read(mapping); if (!more) goto out; -- 2.26.2 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
