diff mbox series

[net-next,v2,5/5] netmem: add netmem_prefetch

Message ID 20241107212309.3097362-6-almasrymina@google.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series devmem TCP fixes | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 42 this patch: 42
netdev/build_tools success Errors and warnings before: 2 (+0) this patch: 2 (+0)
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 78 this patch: 78
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5000 this patch: 5000
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 11 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Mina Almasry Nov. 7, 2024, 9:23 p.m. UTC 
prefect(page) is a common thing to be called from drivers. Add
netmem_prefetch that can be called on generic netmem. Skips the prefetch
for net_iovs.

Signed-off-by: Mina Almasry <almasrymina@google.com>
---
 include/net/netmem.h | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

kernel test robot Nov. 8, 2024, 2:56 a.m. UTC | #1 
Hi Mina,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Mina-Almasry/net-page_pool-rename-page_pool_alloc_netmem-to-_netmems/20241108-052530
base:   net-next/main
patch link:    https://lore.kernel.org/r/20241107212309.3097362-6-almasrymina%40google.com
patch subject: [PATCH net-next v2 5/5] netmem: add netmem_prefetch
config: parisc-allmodconfig (https://download.01.org/0day-ci/archive/20241108/202411081014.jmz4uf6C-lkp@intel.com/config)
compiler: hppa-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241108/202411081014.jmz4uf6C-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411081014.jmz4uf6C-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from include/linux/skbuff.h:40,
                    from net/ipv4/tcp_vegas.c:37:
   include/net/netmem.h: In function 'netmem_prefetch':
   include/net/netmem.h:179:9: error: implicit declaration of function 'prefetch' [-Wimplicit-function-declaration]
     179 |         prefetch(netmem_to_page(netmem));
         |         ^~~~~~~~
   net/ipv4/tcp_vegas.c: At top level:
>> net/ipv4/tcp_vegas.c:46:12: warning: 'gamma' defined but not used [-Wunused-variable]
      46 | static int gamma = 1;
         |            ^~~~~


vim +/gamma +46 net/ipv4/tcp_vegas.c

7752237e9f07b3 Stephen Hemminger 2007-04-23  43  
8d3a564da34e58 Doug Leith        2008-12-09  44  static int alpha = 2;
8d3a564da34e58 Doug Leith        2008-12-09  45  static int beta  = 4;
8d3a564da34e58 Doug Leith        2008-12-09 @46  static int gamma = 1;
b87d8561d8667d Stephen Hemminger 2005-06-23  47
kernel test robot Nov. 8, 2024, 3:29 a.m. UTC | #2 
Hi Mina,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Mina-Almasry/net-page_pool-rename-page_pool_alloc_netmem-to-_netmems/20241108-052530
base:   net-next/main
patch link:    https://lore.kernel.org/r/20241107212309.3097362-6-almasrymina%40google.com
patch subject: [PATCH net-next v2 5/5] netmem: add netmem_prefetch
config: s390-allmodconfig (https://download.01.org/0day-ci/archive/20241108/202411081105.Z1kEMaBE-lkp@intel.com/config)
compiler: clang version 20.0.0git (https://github.com/llvm/llvm-project 592c0fe55f6d9a811028b5f3507be91458ab2713)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241108/202411081105.Z1kEMaBE-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411081105.Z1kEMaBE-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from arch/s390/kernel/asm-offsets.c:11:
   In file included from include/linux/kvm_host.h:16:
   In file included from include/linux/mm.h:2213:
   include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     504 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     505 |                            item];
         |                            ~~~~
   include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     511 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     512 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     524 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     525 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   In file included from arch/s390/kernel/asm-offsets.c:11:
   In file included from include/linux/kvm_host.h:19:
   In file included from include/linux/msi.h:24:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:14:
   In file included from arch/s390/include/asm/io.h:95:
   include/asm-generic/io.h:548:31: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     548 |         val = __raw_readb(PCI_IOBASE + addr);
         |                           ~~~~~~~~~~ ^
   include/asm-generic/io.h:561:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     561 |         val = __le16_to_cpu((__le16 __force)__raw_readw(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:37:59: note: expanded from macro '__le16_to_cpu'
      37 | #define __le16_to_cpu(x) __swab16((__force __u16)(__le16)(x))
         |                                                           ^
   include/uapi/linux/swab.h:102:54: note: expanded from macro '__swab16'
     102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
         |                                                      ^
   In file included from arch/s390/kernel/asm-offsets.c:11:
   In file included from include/linux/kvm_host.h:19:
   In file included from include/linux/msi.h:24:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:14:
   In file included from arch/s390/include/asm/io.h:95:
   include/asm-generic/io.h:574:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     574 |         val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
         |                                                         ~~~~~~~~~~ ^
   include/uapi/linux/byteorder/big_endian.h:35:59: note: expanded from macro '__le32_to_cpu'
      35 | #define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
         |                                                           ^
   include/uapi/linux/swab.h:115:54: note: expanded from macro '__swab32'
     115 | #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
         |                                                      ^
   In file included from arch/s390/kernel/asm-offsets.c:11:
   In file included from include/linux/kvm_host.h:19:
   In file included from include/linux/msi.h:24:
   In file included from include/linux/irq.h:20:
   In file included from include/linux/io.h:14:
   In file included from arch/s390/include/asm/io.h:95:
   include/asm-generic/io.h:585:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     585 |         __raw_writeb(value, PCI_IOBASE + addr);
         |                             ~~~~~~~~~~ ^
   include/asm-generic/io.h:595:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     595 |         __raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:605:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     605 |         __raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
         |                                                       ~~~~~~~~~~ ^
   include/asm-generic/io.h:693:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     693 |         readsb(PCI_IOBASE + addr, buffer, count);
         |                ~~~~~~~~~~ ^
   include/asm-generic/io.h:701:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     701 |         readsw(PCI_IOBASE + addr, buffer, count);
         |                ~~~~~~~~~~ ^
   include/asm-generic/io.h:709:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     709 |         readsl(PCI_IOBASE + addr, buffer, count);
         |                ~~~~~~~~~~ ^
   include/asm-generic/io.h:718:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     718 |         writesb(PCI_IOBASE + addr, buffer, count);
         |                 ~~~~~~~~~~ ^
   include/asm-generic/io.h:727:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     727 |         writesw(PCI_IOBASE + addr, buffer, count);
         |                 ~~~~~~~~~~ ^
   include/asm-generic/io.h:736:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
     736 |         writesl(PCI_IOBASE + addr, buffer, count);
         |                 ~~~~~~~~~~ ^
   In file included from arch/s390/kernel/asm-offsets.c:11:
   In file included from include/linux/kvm_host.h:41:
   In file included from include/linux/kvm_para.h:5:
   In file included from include/uapi/linux/kvm_para.h:37:
   In file included from arch/s390/include/asm/kvm_para.h:25:
   In file included from arch/s390/include/asm/diag.h:12:
   In file included from include/linux/if_ether.h:19:
   In file included from include/linux/skbuff.h:40:
>> include/net/netmem.h:179:2: error: call to undeclared function 'prefetch'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     179 |         prefetch(netmem_to_page(netmem));
         |         ^
   16 warnings and 1 error generated.
   make[3]: *** [scripts/Makefile.build:102: arch/s390/kernel/asm-offsets.s] Error 1
   make[3]: Target 'prepare' not remade because of errors.
   make[2]: *** [Makefile:1203: prepare0] Error 2
   make[2]: Target 'prepare' not remade because of errors.
   make[1]: *** [Makefile:224: __sub-make] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:224: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.


vim +/prefetch +179 include/net/netmem.h

   173	
   174	static inline void netmem_prefetch(netmem_ref netmem)
   175	{
   176		if (netmem_is_net_iov(netmem))
   177			return;
   178	
 > 179		prefetch(netmem_to_page(netmem));
kernel test robot Nov. 8, 2024, 4:21 a.m. UTC | #3 
Hi Mina,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Mina-Almasry/net-page_pool-rename-page_pool_alloc_netmem-to-_netmems/20241108-052530
base:   net-next/main
patch link:    https://lore.kernel.org/r/20241107212309.3097362-6-almasrymina%40google.com
patch subject: [PATCH net-next v2 5/5] netmem: add netmem_prefetch
config: s390-allyesconfig (https://download.01.org/0day-ci/archive/20241108/202411081130.CxioaC2A-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241108/202411081130.CxioaC2A-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411081130.CxioaC2A-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from include/linux/skbuff.h:40,
                    from include/linux/if_ether.h:19,
                    from arch/s390/include/asm/diag.h:12,
                    from arch/s390/include/asm/kvm_para.h:25,
                    from include/uapi/linux/kvm_para.h:37,
                    from include/linux/kvm_para.h:5,
                    from include/linux/kvm_host.h:41,
                    from arch/s390/kernel/asm-offsets.c:11:
   include/net/netmem.h: In function 'netmem_prefetch':
>> include/net/netmem.h:179:9: error: implicit declaration of function 'prefetch' [-Wimplicit-function-declaration]
     179 |         prefetch(netmem_to_page(netmem));
         |         ^~~~~~~~
   make[3]: *** [scripts/Makefile.build:102: arch/s390/kernel/asm-offsets.s] Error 1
   make[3]: Target 'prepare' not remade because of errors.
   make[2]: *** [Makefile:1203: prepare0] Error 2
   make[2]: Target 'prepare' not remade because of errors.
   make[1]: *** [Makefile:224: __sub-make] Error 2
   make[1]: Target 'prepare' not remade because of errors.
   make: *** [Makefile:224: __sub-make] Error 2
   make: Target 'prepare' not remade because of errors.


vim +/prefetch +179 include/net/netmem.h

   173	
   174	static inline void netmem_prefetch(netmem_ref netmem)
   175	{
   176		if (netmem_is_net_iov(netmem))
   177			return;
   178	
 > 179		prefetch(netmem_to_page(netmem));
Stanislav Fomichev Nov. 8, 2024, 3:55 p.m. UTC | #4 
On 11/07, Mina Almasry wrote:
> prefect(page) is a common thing to be called from drivers. Add
> netmem_prefetch that can be called on generic netmem. Skips the prefetch
> for net_iovs.
> 
> Signed-off-by: Mina Almasry <almasrymina@google.com>

Needs some extra includes to make the build bot happy, after that:
Acked-by: Stanislav Fomichev <sdf@fomichev.me>

---
pw-bot: cr
Jakub Kicinski Nov. 12, 2024, 2:35 a.m. UTC | #5 
On Thu,  7 Nov 2024 21:23:09 +0000 Mina Almasry wrote:
> prefect(page) is a common thing to be called from drivers. Add
> netmem_prefetch that can be called on generic netmem. Skips the prefetch
> for net_iovs.

Why would you ever need to prefetch a payload buffer?
Looks wrong..
diff mbox series

Patch

diff --git a/include/net/netmem.h b/include/net/netmem.h
index 8a6e20be4b9d..923c47147aa8 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -171,4 +171,11 @@  static inline unsigned long netmem_get_dma_addr(netmem_ref netmem)
 	return __netmem_clear_lsb(netmem)->dma_addr;
 }
 
+static inline void netmem_prefetch(netmem_ref netmem)
+{
+	if (netmem_is_net_iov(netmem))
+		return;
+
+	prefetch(netmem_to_page(netmem));
+}
 #endif /* _NET_NETMEM_H */