Messages in this thread | | | Date | Wed, 13 Jan 2010 22:36:05 +0800 | From | Américo Wang <> | Subject | Re: [PATCH v5] add MAP_UNLOCKED mmap flag |
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On Wed, Jan 13, 2010 at 11:31:19AM +0200, Gleb Natapov wrote: >If application does mlockall(MCL_FUTURE) it is no longer possible to mmap >file bigger than main memory or allocate big area of anonymous memory >in a thread safe manner. Sometimes it is desirable to lock everything >related to program execution into memory, but still be able to mmap >big file or allocate huge amount of memory and allow OS to swap them on >demand. MAP_UNLOCKED allows to do that. > >Signed-off-by: Gleb Natapov <gleb@redhat.com>
Thanks for keeping working on it.
This version looks fine for me.
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
>--- > >I get reports that people find this useful, so resending. > > v1->v2 > - adding new flag to all archs > - fixing typo > v2->v3 > - one more typo fix > v3->v4 > - return error if MAP_LOCKED | MAP_UNLOCKED is specified > v4->v5 > - rebase to latest head > >diff --git a/arch/alpha/include/asm/mman.h b/arch/alpha/include/asm/mman.h >index 99c56d4..cfc51ac 100644 >--- a/arch/alpha/include/asm/mman.h >+++ b/arch/alpha/include/asm/mman.h >@@ -30,6 +30,7 @@ > #define MAP_NONBLOCK 0x40000 /* do not block on IO */ > #define MAP_STACK 0x80000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x100000 /* create a huge page mapping */ >+#define MAP_UNLOCKED 0x200000 /* force page unlocking */ > > #define MS_ASYNC 1 /* sync memory asynchronously */ > #define MS_SYNC 2 /* synchronous memory sync */ >diff --git a/arch/mips/include/asm/mman.h b/arch/mips/include/asm/mman.h >index c892bfb..3e4d108 100644 >--- a/arch/mips/include/asm/mman.h >+++ b/arch/mips/include/asm/mman.h >@@ -48,6 +48,7 @@ > #define MAP_NONBLOCK 0x20000 /* do not block on IO */ > #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x80000 /* create a huge page mapping */ >+#define MAP_UNLOCKED 0x100000 /* force page unlocking */ > > /* > * Flags for msync >diff --git a/arch/parisc/include/asm/mman.h b/arch/parisc/include/asm/mman.h >index 9749c8a..4e8b9bf 100644 >--- a/arch/parisc/include/asm/mman.h >+++ b/arch/parisc/include/asm/mman.h >@@ -24,6 +24,7 @@ > #define MAP_NONBLOCK 0x20000 /* do not block on IO */ > #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x80000 /* create a huge page mapping */ >+#define MAP_UNLOCKED 0x100000 /* force page unlocking */ > > #define MS_SYNC 1 /* synchronous memory sync */ > #define MS_ASYNC 2 /* sync memory asynchronously */ >diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h >index d4a7f64..7d33f01 100644 >--- a/arch/powerpc/include/asm/mman.h >+++ b/arch/powerpc/include/asm/mman.h >@@ -27,6 +27,7 @@ > #define MAP_NONBLOCK 0x10000 /* do not block on IO */ > #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ >+#define MAP_UNLOCKED 0x80000 /* force page unlocking */ > > #ifdef __KERNEL__ > #ifdef CONFIG_PPC64 >diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h >index c3029ad..f80d203 100644 >--- a/arch/sparc/include/asm/mman.h >+++ b/arch/sparc/include/asm/mman.h >@@ -22,6 +22,7 @@ > #define MAP_NONBLOCK 0x10000 /* do not block on IO */ > #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ >+#define MAP_UNLOCKED 0x80000 /* force page unlocking */ > > #ifdef __KERNEL__ > #ifndef __ASSEMBLY__ >diff --git a/arch/xtensa/include/asm/mman.h b/arch/xtensa/include/asm/mman.h >index fca4db4..c62bcd8 100644 >--- a/arch/xtensa/include/asm/mman.h >+++ b/arch/xtensa/include/asm/mman.h >@@ -55,6 +55,7 @@ > #define MAP_NONBLOCK 0x20000 /* do not block on IO */ > #define MAP_STACK 0x40000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x80000 /* create a huge page mapping */ >+#define MAP_UNLOCKED 0x100000 /* force page unlocking */ > > /* > * Flags for msync >diff --git a/include/asm-generic/mman.h b/include/asm-generic/mman.h >index 32c8bd6..59e0f29 100644 >--- a/include/asm-generic/mman.h >+++ b/include/asm-generic/mman.h >@@ -12,6 +12,7 @@ > #define MAP_NONBLOCK 0x10000 /* do not block on IO */ > #define MAP_STACK 0x20000 /* give out an address that is best suited for process/thread stacks */ > #define MAP_HUGETLB 0x40000 /* create a huge page mapping */ >+#define MAP_UNLOCKED 0x80000 /* force page unlocking */ > > #define MCL_CURRENT 1 /* lock all current mappings */ > #define MCL_FUTURE 2 /* lock all future mappings */ >diff --git a/mm/mmap.c b/mm/mmap.c >index ee22989..4bda220 100644 >--- a/mm/mmap.c >+++ b/mm/mmap.c >@@ -962,6 +962,9 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr, > if (!can_do_mlock()) > return -EPERM; > >+ if (flags & MAP_UNLOCKED) >+ vm_flags &= ~VM_LOCKED; >+ > /* mlock MCL_FUTURE? */ > if (vm_flags & VM_LOCKED) { > unsigned long locked, lock_limit; >@@ -1050,7 +1053,10 @@ SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len, > struct file *file = NULL; > unsigned long retval = -EBADF; > >- if (!(flags & MAP_ANONYMOUS)) { >+ if (unlikely((flags & (MAP_LOCKED | MAP_UNLOCKED)) == >+ (MAP_LOCKED | MAP_UNLOCKED))) { >+ return -EINVAL; >+ } else if (!(flags & MAP_ANONYMOUS)) { > if (unlikely(flags & MAP_HUGETLB)) > return -EINVAL; > file = fget(fd); >-- > Gleb. >-- >To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html >Please read the FAQ at http://www.tux.org/lkml/
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