Messages in this thread Patch in this message |  | | | Date | Mon, 30 Jul 2012 07:11:25 -0700 | | From | tip-bot for Oleg Nesterov <> | | Subject | [tip:perf/core] uprobes: Kill write_opcode()->lock_page(new_page) |
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Commit-ID: 089ba999dc881a7549d97c55ac9e0052d061867d Gitweb: http://git.kernel.org/tip/089ba999dc881a7549d97c55ac9e0052d061867d Author: Oleg Nesterov <oleg@redhat.com> AuthorDate: Sun, 29 Jul 2012 20:22:18 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 30 Jul 2012 11:27:19 +0200
uprobes: Kill write_opcode()->lock_page(new_page)
write_opcode() does lock_page(new_page) for no reason. Nobody can see this page until __replace_page() exposes it under ptl lock, and we do nothing with this page after pte_unmap_unlock().
If nothing else, the similar code in do_wp_page() doesn't lock the new page for page_add_new_anon_rmap/set_pte_at_notify.
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar.vnet.ibm.com> Cc: Anton Arapov <anton@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20120729182218.GA20315@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- kernel/events/uprobes.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 6fda799..23c562b7 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -239,9 +239,7 @@ retry: if (ret) goto unlock_out; - lock_page(new_page); ret = __replace_page(vma, vaddr, old_page, new_page); - unlock_page(new_page); unlock_out: unlock_page(old_page);
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