From: "Michael S. Tsirkin" <mst@redhat.com> To: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Eduardo Habkost <ehabkost@redhat.com>, pbonzini@redhat.com, imammedo@redhat.com, gleb@kernel.org, mtosatti@redhat.com, stefanha@redhat.com, rth@twiddle.net, dan.j.williams@intel.com, kvm@vger.kernel.org, qemu-devel@nongnu.org Subject: Re: [PATCH v6 07/33] util: introduce qemu_file_get_page_size() Date: Mon, 9 Nov 2015 22:00:52 +0200 [thread overview] Message-ID: <20151109215812-mutt-send-email-mst@redhat.com> (raw) In-Reply-To: <56347754.6090904@linux.intel.com> 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 <guangrong.xiao@linux.intel.com> > >[...] > >>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
WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com> To: Xiao Guangrong <guangrong.xiao@linux.intel.com> Cc: Eduardo Habkost <ehabkost@redhat.com>, kvm@vger.kernel.org, gleb@kernel.org, mtosatti@redhat.com, qemu-devel@nongnu.org, stefanha@redhat.com, imammedo@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, rth@twiddle.net Subject: Re: [Qemu-devel] [PATCH v6 07/33] util: introduce qemu_file_get_page_size() Date: Mon, 9 Nov 2015 22:00:52 +0200 [thread overview] Message-ID: <20151109215812-mutt-send-email-mst@redhat.com> (raw) In-Reply-To: <56347754.6090904@linux.intel.com> 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 <guangrong.xiao@linux.intel.com> > >[...] > >>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
next prev parent reply other threads:[~2015-11-09 20:00 UTC|newest] Thread overview: 182+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-10-30 5:55 [PATCH v6 00/33] implement vNVDIMM Xiao Guangrong 2015-10-30 5:55 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:55 ` [PATCH v6 01/33] acpi: add aml_derefof Xiao Guangrong 2015-10-30 5:55 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:55 ` [PATCH v6 02/33] acpi: add aml_sizeof Xiao Guangrong 2015-10-30 5:55 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:55 ` [PATCH v6 03/33] acpi: add aml_create_field Xiao Guangrong 2015-10-30 5:55 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:55 ` [PATCH v6 04/33] acpi: add aml_concatenate Xiao Guangrong 2015-10-30 5:55 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:55 ` [PATCH v6 05/33] acpi: add aml_object_type Xiao Guangrong 2015-10-30 5:55 ` [Qemu-devel] " Xiao Guangrong 2015-11-09 11:35 ` Michael S. Tsirkin 2015-11-09 11:35 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 12:40 ` Igor Mammedov 2015-11-09 12:40 ` [Qemu-devel] " Igor Mammedov 2015-10-30 5:56 ` [PATCH v6 06/33] acpi: add aml_method_serialized Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-11-09 11:14 ` Michael S. Tsirkin 2015-11-09 11:14 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 11:18 ` Xiao Guangrong 2015-11-09 11:18 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 07/33] util: introduce qemu_file_get_page_size() Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 13:26 ` Vladimir Sementsov-Ogievskiy 2015-10-30 13:26 ` Vladimir Sementsov-Ogievskiy 2015-10-31 7:26 ` Xiao Guangrong 2015-10-31 7:26 ` [Qemu-devel] " Xiao Guangrong 2015-10-31 9:37 ` Vladimir Sementsov-Ogievskiy 2015-10-31 9:37 ` Vladimir Sementsov-Ogievskiy 2015-10-31 14:06 ` Xiao Guangrong 2015-10-31 14:06 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 15:54 ` Eduardo Habkost 2015-10-30 15:54 ` [Qemu-devel] " Eduardo Habkost 2015-10-31 8:09 ` Xiao Guangrong 2015-10-31 8:09 ` [Qemu-devel] " Xiao Guangrong 2015-10-31 14:11 ` Eduardo Habkost 2015-10-31 14:11 ` [Qemu-devel] " Eduardo Habkost 2015-10-31 17:03 ` Xiao Guangrong 2015-10-31 17:03 ` [Qemu-devel] " Xiao Guangrong 2015-11-09 20:00 ` Michael S. Tsirkin [this message] 2015-11-09 20:00 ` Michael S. Tsirkin 2015-10-31 8:25 ` Xiao Guangrong 2015-10-31 8:25 ` [Qemu-devel] " Xiao Guangrong 2015-11-09 10:33 ` Michael S. Tsirkin 2015-11-09 10:33 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 10:55 ` Xiao Guangrong 2015-11-09 10:55 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 08/33] exec: allow memory to be allocated from any kind of path Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 14:04 ` Vladimir Sementsov-Ogievskiy 2015-10-30 14:04 ` Vladimir Sementsov-Ogievskiy 2015-10-31 7:44 ` Xiao Guangrong 2015-10-31 13:55 ` Eduardo Habkost 2015-10-31 13:55 ` Eduardo Habkost 2015-10-31 15:56 ` Xiao Guangrong 2015-10-31 15:56 ` Xiao Guangrong 2015-11-09 10:39 ` Michael S. Tsirkin 2015-11-09 10:39 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 11:01 ` Xiao Guangrong 2015-11-09 11:01 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 09/33] exec: allow file_ram_alloc to work on file Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 14:25 ` Vladimir Sementsov-Ogievskiy 2015-10-30 14:25 ` Vladimir Sementsov-Ogievskiy 2015-10-31 7:53 ` Xiao Guangrong 2015-10-31 7:53 ` [Qemu-devel] " Xiao Guangrong 2015-11-09 10:13 ` Michael S. Tsirkin 2015-11-09 10:13 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 10:48 ` Xiao Guangrong 2015-11-09 10:48 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 10/33] hostmem-file: clean up memory allocation Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 14:54 ` Vladimir Sementsov-Ogievskiy 2015-10-30 14:54 ` Vladimir Sementsov-Ogievskiy 2015-10-30 5:56 ` [PATCH v6 11/33] hostmem-file: use whole file size if possible Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 15:27 ` Vladimir Sementsov-Ogievskiy 2015-10-30 15:27 ` Vladimir Sementsov-Ogievskiy 2015-10-31 7:59 ` Xiao Guangrong 2015-10-31 7:59 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 17:30 ` Eduardo Habkost 2015-10-30 17:30 ` Eduardo Habkost 2015-10-31 8:46 ` Xiao Guangrong 2015-10-31 8:46 ` Xiao Guangrong 2015-10-31 13:45 ` Eduardo Habkost 2015-10-31 13:45 ` Eduardo Habkost 2015-10-31 16:59 ` Xiao Guangrong 2015-10-31 16:59 ` [Qemu-devel] " Xiao Guangrong 2015-11-09 10:17 ` Michael S. Tsirkin 2015-11-09 10:17 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 10:49 ` Xiao Guangrong 2015-11-09 10:49 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 12/33] pc-dimm: remove DEFAULT_PC_DIMMSIZE Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-11-09 10:40 ` Michael S. Tsirkin 2015-11-09 10:40 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 11:03 ` Xiao Guangrong 2015-11-09 11:03 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 13/33] pc-dimm: make pc_existing_dimms_capacity static and rename it Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 15:38 ` Vladimir Sementsov-Ogievskiy 2015-10-30 15:38 ` Vladimir Sementsov-Ogievskiy 2015-10-30 5:56 ` [PATCH v6 14/33] pc-dimm: drop the prefix of pc-dimm Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 16:10 ` Vladimir Sementsov-Ogievskiy 2015-10-30 16:10 ` Vladimir Sementsov-Ogievskiy 2015-10-31 8:18 ` Xiao Guangrong 2015-10-30 17:06 ` Eric Blake 2015-10-31 8:23 ` Xiao Guangrong 2015-11-09 20:05 ` Michael S. Tsirkin 2015-11-09 20:05 ` [Qemu-devel] " Michael S. Tsirkin 2015-10-30 5:56 ` [PATCH v6 15/33] stubs: rename qmp_pc_dimm_device_list.c Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 16/33] pc-dimm: rename pc-dimm.c and pc-dimm.h Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-31 10:28 ` Vladimir Sementsov-Ogievskiy 2015-10-31 10:28 ` Vladimir Sementsov-Ogievskiy 2015-10-30 5:56 ` [PATCH v6 17/33] dimm: abstract dimm device from pc-dimm Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-31 10:41 ` Vladimir Sementsov-Ogievskiy 2015-10-31 10:41 ` [Qemu-devel] " Vladimir Sementsov-Ogievskiy 2015-10-30 5:56 ` [PATCH v6 18/33] dimm: get mapped memory region from DIMMDeviceClass->get_memory_region Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-31 10:52 ` Vladimir Sementsov-Ogievskiy 2015-10-31 10:52 ` Vladimir Sementsov-Ogievskiy 2015-10-31 14:15 ` Xiao Guangrong 2015-10-31 14:15 ` [Qemu-devel] " Xiao Guangrong 2015-11-02 9:18 ` Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 19/33] dimm: keep the state of the whole backend memory Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-31 11:05 ` Vladimir Sementsov-Ogievskiy 2015-10-31 11:05 ` Vladimir Sementsov-Ogievskiy 2015-10-31 14:19 ` Xiao Guangrong 2015-11-09 11:04 ` Michael S. Tsirkin 2015-11-09 11:04 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 11:13 ` Xiao Guangrong 2015-11-09 11:13 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 20/33] dimm: introduce realize callback Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-31 11:22 ` Vladimir Sementsov-Ogievskiy 2015-10-31 11:22 ` [Qemu-devel] " Vladimir Sementsov-Ogievskiy 2015-10-30 5:56 ` [PATCH v6 21/33] nvdimm: implement NVDIMM device abstract Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 22/33] docs: add NVDIMM ACPI documentation Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 23/33] nvdimm acpi: init the resource used by NVDIMM ACPI Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 24/33] nvdimm acpi: build ACPI NFIT table Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 25/33] nvdimm acpi: build ACPI nvdimm devices Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-11-08 17:38 ` Michael S. Tsirkin 2015-11-08 17:38 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 6:07 ` Xiao Guangrong 2015-11-09 6:07 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 26/33] nvdimm acpi: save arg3 for NVDIMM device _DSM method Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 27/33] nvdimm acpi: support function 0 Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 10:14 ` Stefan Hajnoczi 2015-10-30 10:14 ` [Qemu-devel] " Stefan Hajnoczi 2015-10-30 13:01 ` Xiao Guangrong 2015-10-30 13:01 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 28/33] nvdimm acpi: support Get Namespace Label Size function Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 29/33] nvdimm acpi: support Get Namespace Label Data function Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 30/33] nvdimm acpi: support Set " Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 31/33] nvdimm: allow using whole backend memory as pmem Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 32/33] nvdimm acpi: support _FIT method Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-11-08 17:50 ` Michael S. Tsirkin 2015-11-08 17:50 ` [Qemu-devel] " Michael S. Tsirkin 2015-11-09 6:37 ` Xiao Guangrong 2015-11-09 6:37 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 5:56 ` [PATCH v6 33/33] nvdimm: add maintain info Xiao Guangrong 2015-10-30 5:56 ` [Qemu-devel] " Xiao Guangrong 2015-10-30 10:15 ` [PATCH v6 00/33] implement vNVDIMM Stefan Hajnoczi 2015-10-30 10:15 ` [Qemu-devel] " Stefan Hajnoczi
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