diff options
author | Song Liu <songliubraving@fb.com> | 2019-09-24 01:38:19 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-25 01:54:11 +0300 |
commit | 010c164a5fa7e169deab0a4d8211611f1930c1cd (patch) | |
tree | fb07bdd2cf844ccf1e1aaf6fc40e42399fb0dc19 /mm/util.c | |
parent | 87eaceb3faa59b9b4d940ec9554ce251325d83fe (diff) | |
download | linux-010c164a5fa7e169deab0a4d8211611f1930c1cd.tar.xz |
mm: move memcmp_pages() and pages_identical()
Patch series "THP aware uprobe", v13.
This patchset makes uprobe aware of THPs.
Currently, when uprobe is attached to text on THP, the page is split by
FOLL_SPLIT. As a result, uprobe eliminates the performance benefit of
THP.
This set makes uprobe THP-aware. Instead of FOLL_SPLIT, we introduces
FOLL_SPLIT_PMD, which only split PMD for uprobe.
After all uprobes within the THP are removed, the PTE-mapped pages are
regrouped as huge PMD.
This set (plus a few THP patches) is also available at
https://github.com/liu-song-6/linux/tree/uprobe-thp
This patch (of 6):
Move memcmp_pages() to mm/util.c and pages_identical() to mm.h, so that we
can use them in other files.
Link: http://lkml.kernel.org/r/20190815164525.1848545-2-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox <matthew.wilcox@oracle.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/util.c')
-rw-r--r-- | mm/util.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/mm/util.c b/mm/util.c index bab284d69c8c..37f7b6711514 100644 --- a/mm/util.c +++ b/mm/util.c @@ -783,3 +783,16 @@ out_mm: out: return res; } + +int memcmp_pages(struct page *page1, struct page *page2) +{ + char *addr1, *addr2; + int ret; + + addr1 = kmap_atomic(page1); + addr2 = kmap_atomic(page2); + ret = memcmp(addr1, addr2, PAGE_SIZE); + kunmap_atomic(addr2); + kunmap_atomic(addr1); + return ret; +} |