| Message ID | 20140204184153.GA25368@amt.cnet |
|---|---|
| State | New |
| Headers | show |
On Tue, Feb 04, 2014 at 01:41:53PM -0500, Marcelo Tosatti wrote: > > -mem-prealloc asks to preallocate memory residing on -mem-path path. > > Currently QEMU exits in case: > > - Memory file has been created but allocation via explicit write > fails. > > And it fallbacks to malloc in case: > - Querying huge page size fails. > - Lack of sync MMU support. > - Open fails. > - mmap fails. > > Have the same behaviour for all cases: fail in case -mem-path and > -mem-prealloc are specified for regions where the requested size is > suitable for hugepages. > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Forgot uq/master on the subject (but its aimed for that tree).
Il 04/02/2014 19:41, Marcelo Tosatti ha scritto: > > -mem-prealloc asks to preallocate memory residing on -mem-path path. > > Currently QEMU exits in case: > > - Memory file has been created but allocation via explicit write > fails. > > And it fallbacks to malloc in case: > - Querying huge page size fails. > - Lack of sync MMU support. > - Open fails. > - mmap fails. > > Have the same behaviour for all cases: fail in case -mem-path and > -mem-prealloc are specified for regions where the requested size is > suitable for hugepages. > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > > diff --git a/exec.c b/exec.c > index 9ad0a4b..1da1ba7 100644 > --- a/exec.c > +++ b/exec.c > @@ -996,7 +996,7 @@ static void *file_ram_alloc(RAMBlock *block, > > hpagesize = gethugepagesize(path); > if (!hpagesize) { > - return NULL; > + goto error; > } > > if (memory < hpagesize) { > @@ -1005,7 +1005,7 @@ static void *file_ram_alloc(RAMBlock *block, > > if (kvm_enabled() && !kvm_has_sync_mmu()) { > fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n"); > - return NULL; > + goto error; > } > > /* Make name safe to use with mkstemp by replacing '/' with '_'. */ > @@ -1023,7 +1023,7 @@ static void *file_ram_alloc(RAMBlock *block, > if (fd < 0) { > perror("unable to create backing store for hugepages"); > g_free(filename); > - return NULL; > + goto error; > } > unlink(filename); > g_free(filename); > @@ -1043,7 +1043,7 @@ static void *file_ram_alloc(RAMBlock *block, > if (area == MAP_FAILED) { > perror("file_ram_alloc: can't mmap RAM pages"); > close(fd); > - return (NULL); > + goto error; > } > > if (mem_prealloc) { > @@ -1087,6 +1087,12 @@ static void *file_ram_alloc(RAMBlock *block, > > block->fd = fd; > return area; > + > +error: > + if (mem_prealloc) { > + exit(1); > + } > + return NULL; > } > #else > static void *file_ram_alloc(RAMBlock *block, > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Will apply soon.
Il 04/02/2014 19:41, Marcelo Tosatti ha scritto: > > -mem-prealloc asks to preallocate memory residing on -mem-path path. > > Currently QEMU exits in case: > > - Memory file has been created but allocation via explicit write > fails. > > And it fallbacks to malloc in case: > - Querying huge page size fails. > - Lack of sync MMU support. > - Open fails. > - mmap fails. > > Have the same behaviour for all cases: fail in case -mem-path and > -mem-prealloc are specified for regions where the requested size is > suitable for hugepages. > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Once we introduce memdev, I believe -mem-path should always exit, and never fall back to malloc/MAP_ANON. For 2.0, I'm applying the patch to uq/master. Paolo > diff --git a/exec.c b/exec.c > index 9ad0a4b..1da1ba7 100644 > --- a/exec.c > +++ b/exec.c > @@ -996,7 +996,7 @@ static void *file_ram_alloc(RAMBlock *block, > > hpagesize = gethugepagesize(path); > if (!hpagesize) { > - return NULL; > + goto error; > } > > if (memory < hpagesize) { > @@ -1005,7 +1005,7 @@ static void *file_ram_alloc(RAMBlock *block, > > if (kvm_enabled() && !kvm_has_sync_mmu()) { > fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n"); > - return NULL; > + goto error; > } > > /* Make name safe to use with mkstemp by replacing '/' with '_'. */ > @@ -1023,7 +1023,7 @@ static void *file_ram_alloc(RAMBlock *block, > if (fd < 0) { > perror("unable to create backing store for hugepages"); > g_free(filename); > - return NULL; > + goto error; > } > unlink(filename); > g_free(filename); > @@ -1043,7 +1043,7 @@ static void *file_ram_alloc(RAMBlock *block, > if (area == MAP_FAILED) { > perror("file_ram_alloc: can't mmap RAM pages"); > close(fd); > - return (NULL); > + goto error; > } > > if (mem_prealloc) { > @@ -1087,6 +1087,12 @@ static void *file_ram_alloc(RAMBlock *block, > > block->fd = fd; > return area; > + > +error: > + if (mem_prealloc) { > + exit(1); > + } > + return NULL; > } > #else > static void *file_ram_alloc(RAMBlock *block, >
On Thu, Feb 27, 2014 at 07:30:26PM +0100, Paolo Bonzini wrote: > Il 04/02/2014 19:41, Marcelo Tosatti ha scritto: > > > >-mem-prealloc asks to preallocate memory residing on -mem-path path. > > > >Currently QEMU exits in case: > > > >- Memory file has been created but allocation via explicit write > >fails. > > > >And it fallbacks to malloc in case: > >- Querying huge page size fails. > >- Lack of sync MMU support. > >- Open fails. > >- mmap fails. > > > >Have the same behaviour for all cases: fail in case -mem-path and > >-mem-prealloc are specified for regions where the requested size is > >suitable for hugepages. > > > >Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > > Once we introduce memdev, I believe -mem-path should always exit, > and never fall back to malloc/MAP_ANON. Agree.
On Thu, 27 Feb 2014 19:30:26 +0100 Paolo Bonzini <pbonzini@redhat.com> wrote: > Il 04/02/2014 19:41, Marcelo Tosatti ha scritto: > > > > -mem-prealloc asks to preallocate memory residing on -mem-path path. > > > > Currently QEMU exits in case: > > > > - Memory file has been created but allocation via explicit write > > fails. > > > > And it fallbacks to malloc in case: > > - Querying huge page size fails. > > - Lack of sync MMU support. > > - Open fails. > > - mmap fails. > > > > Have the same behaviour for all cases: fail in case -mem-path and > > -mem-prealloc are specified for regions where the requested size is > > suitable for hugepages. > > > > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> > > Once we introduce memdev, I believe -mem-path should always exit, and > never fall back to malloc/MAP_ANON. perhaps it should return a error instead of exit. Exit would be bad for hotplug case, hotplug op should fail and not crash machine. > For 2.0, I'm applying the patch to uq/master. > > Paolo > > > diff --git a/exec.c b/exec.c > > index 9ad0a4b..1da1ba7 100644 > > --- a/exec.c > > +++ b/exec.c > > @@ -996,7 +996,7 @@ static void *file_ram_alloc(RAMBlock *block, > > > > hpagesize = gethugepagesize(path); > > if (!hpagesize) { > > - return NULL; > > + goto error; > > } > > > > if (memory < hpagesize) { > > @@ -1005,7 +1005,7 @@ static void *file_ram_alloc(RAMBlock *block, > > > > if (kvm_enabled() && !kvm_has_sync_mmu()) { > > fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n"); > > - return NULL; > > + goto error; > > } > > > > /* Make name safe to use with mkstemp by replacing '/' with '_'. */ > > @@ -1023,7 +1023,7 @@ static void *file_ram_alloc(RAMBlock *block, > > if (fd < 0) { > > perror("unable to create backing store for hugepages"); > > g_free(filename); > > - return NULL; > > + goto error; > > } > > unlink(filename); > > g_free(filename); > > @@ -1043,7 +1043,7 @@ static void *file_ram_alloc(RAMBlock *block, > > if (area == MAP_FAILED) { > > perror("file_ram_alloc: can't mmap RAM pages"); > > close(fd); > > - return (NULL); > > + goto error; > > } > > > > if (mem_prealloc) { > > @@ -1087,6 +1087,12 @@ static void *file_ram_alloc(RAMBlock *block, > > > > block->fd = fd; > > return area; > > + > > +error: > > + if (mem_prealloc) { > > + exit(1); > > + } > > + return NULL; > > } > > #else > > static void *file_ram_alloc(RAMBlock *block, > > > >
diff --git a/exec.c b/exec.c index 9ad0a4b..1da1ba7 100644 --- a/exec.c +++ b/exec.c @@ -996,7 +996,7 @@ static void *file_ram_alloc(RAMBlock *block, hpagesize = gethugepagesize(path); if (!hpagesize) { - return NULL; + goto error; } if (memory < hpagesize) { @@ -1005,7 +1005,7 @@ static void *file_ram_alloc(RAMBlock *block, if (kvm_enabled() && !kvm_has_sync_mmu()) { fprintf(stderr, "host lacks kvm mmu notifiers, -mem-path unsupported\n"); - return NULL; + goto error; } /* Make name safe to use with mkstemp by replacing '/' with '_'. */ @@ -1023,7 +1023,7 @@ static void *file_ram_alloc(RAMBlock *block, if (fd < 0) { perror("unable to create backing store for hugepages"); g_free(filename); - return NULL; + goto error; } unlink(filename); g_free(filename); @@ -1043,7 +1043,7 @@ static void *file_ram_alloc(RAMBlock *block, if (area == MAP_FAILED) { perror("file_ram_alloc: can't mmap RAM pages"); close(fd); - return (NULL); + goto error; } if (mem_prealloc) { @@ -1087,6 +1087,12 @@ static void *file_ram_alloc(RAMBlock *block, block->fd = fd; return area; + +error: + if (mem_prealloc) { + exit(1); + } + return NULL; } #else static void *file_ram_alloc(RAMBlock *block,
-mem-prealloc asks to preallocate memory residing on -mem-path path. Currently QEMU exits in case: - Memory file has been created but allocation via explicit write fails. And it fallbacks to malloc in case: - Querying huge page size fails. - Lack of sync MMU support. - Open fails. - mmap fails. Have the same behaviour for all cases: fail in case -mem-path and -mem-prealloc are specified for regions where the requested size is suitable for hugepages. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>