]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
x86/events/intel/ds: Map debug buffers in cpu_entry_area
authorHugh Dickins <hughd@google.com>
Mon, 4 Dec 2017 14:07:50 +0000 (15:07 +0100)
committerIngo Molnar <mingo@kernel.org>
Sat, 23 Dec 2017 20:13:00 +0000 (21:13 +0100)
commitc1961a4631daef4aeabee8e368b1b13e8f173c91
treee27322eb539ad6c6f8ddbfa6503f61b81f80264d
parent10043e02db7f8a4161f76434931051e7d797a5f6
x86/events/intel/ds: Map debug buffers in cpu_entry_area

The BTS and PEBS buffers both have their virtual addresses programmed into
the hardware.  This means that any access to them is performed via the page
tables.  The times that the hardware accesses these are entirely dependent
on how the performance monitoring hardware events are set up.  In other
words, there is no way for the kernel to tell when the hardware might
access these buffers.

To avoid perf crashes, place 'debug_store' allocate pages and map them into
the cpu_entry_area.

The PEBS fixup buffer does not need this treatment.

[ tglx: Got rid of the kaiser_add_mapping() complication ]

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/events/intel/ds.c
arch/x86/events/perf_event.h