[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v6 07/33] util: introduce qemu_file_get_page_siz
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH v6 07/33] util: introduce qemu_file_get_page_size() |
Date: |
Mon, 9 Nov 2015 22:00:52 +0200 |
On Sat, Oct 31, 2015 at 04:09:56PM +0800, Xiao Guangrong wrote:
>
>
> On 10/30/2015 11:54 PM, Eduardo Habkost wrote:
> >On Fri, Oct 30, 2015 at 01:56:01PM +0800, Xiao Guangrong wrote:
> >>There are three places use the some logic to get the page size on
> >>the file path or file fd
> >>
> >>This patch introduces qemu_file_get_page_size() to unify the code
> >>
> >>Signed-off-by: Xiao Guangrong <address@hidden>
> >[...]
> >>diff --git a/util/oslib-posix.c b/util/oslib-posix.c
> >>index 914cef5..ad94c5a 100644
> >>--- a/util/oslib-posix.c
> >>+++ b/util/oslib-posix.c
> >>@@ -360,6 +360,22 @@ static size_t fd_getpagesize(int fd)
> >> return getpagesize();
> >> }
> >>
> >>+size_t qemu_file_get_page_size(const char *path)
> >>+{
> >>+ size_t size = 0;
> >>+ int fd = qemu_open(path, O_RDONLY);
> >>+
> >>+ if (fd < 0) {
> >>+ fprintf(stderr, "Could not open %s.\n", path);
> >>+ goto exit;
> >
> >Have you considered using a Error** argument here?
> >
> >>+ }
> >>+
> >>+ size = fd_getpagesize(fd);
> >>+ qemu_close(fd);
> >>+exit:
> >>+ return size;
> >>+}
> >>+
> >>diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
> >>index ac70f08..c661f1c 100644
> >>--- a/target-ppc/kvm.c
> >>+++ b/target-ppc/kvm.c
> >>@@ -308,28 +308,13 @@ static void kvm_get_smmu_info(PowerPCCPU *cpu, struct
> >>kvm_ppc_smmu_info *info)
> >>
> >> static long gethugepagesize(const char *mem_path)
> >> {
> >>- struct statfs fs;
> >>- int ret;
> >>-
> >>- do {
> >>- ret = statfs(mem_path, &fs);
> >>- } while (ret != 0 && errno == EINTR);
> >>+ long size = qemu_file_get_page_size(mem_path);
> >>
> >>- if (ret != 0) {
> >>- fprintf(stderr, "Couldn't statfs() memory path: %s\n",
> >>- strerror(errno));
> >>+ if (!size) {
> >> exit(1);
> >> }
> >>
> >>-#define HUGETLBFS_MAGIC 0x958458f6
> >>-
> >>- if (fs.f_type != HUGETLBFS_MAGIC) {
> >>- /* Explicit mempath, but it's ordinary pages */
> >>- return getpagesize();
> >>- }
> >>-
> >>- /* It's hugepage, return the huge page size */
> >>- return fs.f_bsize;
> >>+ return size;
> >> }
> >
> >Why are you changing target-ppc/kvm.c:gethugepagesize() to use the new
> >funtion, but not the copy at exec.c? To make it simpler, we could
> >eliminate both gethugepagesize() functions completely and replace them
> >with qemu_file_get_page_size() calls (maybe as part of this patch, maybe
> >in a separate patch, I'm not sure).
> >
>
> The gethugepagesize() in exec.c will be eliminated in later patch :).
That's why it's not a good idea to split patchset like this,
where patch 1 adds a new function, patch 2 uses it.
It's better if user is in the same patchset.
An exception if when a completely separate group of people
should review the function and the usage,
e.g. some logic in memory core versus caller in acpi.
> And the gethugepagesize() in ppc platform has error handling logic
> and has multiple caller. It's not so bad to keep it.
>
--
MST