• Rick Edgecombe's avatar
    mm/hibernation: Make hibernation handle unmapped pages · d6332692
    Rick Edgecombe authored
    Make hibernate handle unmapped pages on the direct map when
    CONFIG_ARCH_HAS_SET_ALIAS=y is set. These functions allow for setting pages
    to invalid configurations, so now hibernate should check if the pages have
    valid mappings and handle if they are unmapped when doing a hibernate
    save operation.
    
    Previously this checking was already done when CONFIG_DEBUG_PAGEALLOC=y
    was configured. It does not appear to have a big hibernating performance
    impact. The speed of the saving operation before this change was measured
    as 819.02 MB/s, and after was measured at 813.32 MB/s.
    
    Before:
    [    4.670938] PM: Wrote 171996 kbytes in 0.21 seconds (819.02 MB/s)
    
    After:
    [    4.504714] PM: Wrote 178932 kbytes in 0.22 seconds (813.32 MB/s)
    Signed-off-by: default avatarRick Edgecombe <rick.p.edgecombe@intel.com>
    Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
    Acked-by: default avatarPavel Machek <pavel@ucw.cz>
    Cc: <akpm@linux-foundation.org>
    Cc: <ard.biesheuvel@linaro.org>
    Cc: <deneen.t.dock@intel.com>
    Cc: <kernel-hardening@lists.openwall.com>
    Cc: <kristen@linux.intel.com>
    Cc: <linux_dti@icloud.com>
    Cc: <will.deacon@arm.com>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Dave Hansen <dave.hansen@linux.intel.com>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Nadav Amit <nadav.amit@gmail.com>
    Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
    Cc: Rik van Riel <riel@surriel.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Link: https://lkml.kernel.org/r/20190426001143.4983-16-namit@vmware.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    d6332692
snapshot.c 71.8 KB