| Message ID | 20190620090958.2135-12-kevin.laatz@intel.com |
|---|---|
| State | Awaiting Upstream |
| Headers | show |
| Series | XDP unaligned chunk placement support | expand |
On Thu, 20 Jun 2019 at 19:25, Kevin Laatz <kevin.laatz@intel.com> wrote: > > The addition of unaligned chunks mode, the documentation needs to be > updated to indicate that the incoming addr to the fill ring will only be > masked if the user application is run in the aligned chunk mode. This patch > also adds a line to explicitly indicate that the incoming addr will not be > masked if running the user application in the unaligned chunk mode. > > Signed-off-by: Kevin Laatz <kevin.laatz@intel.com> Acked-by: Björn Töpel <bjorn.topel@intel.com> > --- > Documentation/networking/af_xdp.rst | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/Documentation/networking/af_xdp.rst b/Documentation/networking/af_xdp.rst > index e14d7d40fc75..16fbc68cac50 100644 > --- a/Documentation/networking/af_xdp.rst > +++ b/Documentation/networking/af_xdp.rst > @@ -153,10 +153,12 @@ an example, if the UMEM is 64k and each chunk is 4k, then the UMEM has > > Frames passed to the kernel are used for the ingress path (RX rings). > > -The user application produces UMEM addrs to this ring. Note that the > -kernel will mask the incoming addr. E.g. for a chunk size of 2k, the > -log2(2048) LSB of the addr will be masked off, meaning that 2048, 2050 > -and 3000 refers to the same chunk. > +The user application produces UMEM addrs to this ring. Note that, if > +running the application with aligned chunk mode, the kernel will mask > +the incoming addr. E.g. for a chunk size of 2k, the log2(2048) LSB of > +the addr will be masked off, meaning that 2048, 2050 and 3000 refers > +to the same chunk. If the user application is run in the unaligned > +chunks mode, then the incoming addr will be left untouched. > > > UMEM Completion Ring > -- > 2.17.1 >
diff --git a/Documentation/networking/af_xdp.rst b/Documentation/networking/af_xdp.rst index e14d7d40fc75..16fbc68cac50 100644 --- a/Documentation/networking/af_xdp.rst +++ b/Documentation/networking/af_xdp.rst @@ -153,10 +153,12 @@ an example, if the UMEM is 64k and each chunk is 4k, then the UMEM has Frames passed to the kernel are used for the ingress path (RX rings). -The user application produces UMEM addrs to this ring. Note that the -kernel will mask the incoming addr. E.g. for a chunk size of 2k, the -log2(2048) LSB of the addr will be masked off, meaning that 2048, 2050 -and 3000 refers to the same chunk. +The user application produces UMEM addrs to this ring. Note that, if +running the application with aligned chunk mode, the kernel will mask +the incoming addr. E.g. for a chunk size of 2k, the log2(2048) LSB of +the addr will be masked off, meaning that 2048, 2050 and 3000 refers +to the same chunk. If the user application is run in the unaligned +chunks mode, then the incoming addr will be left untouched. UMEM Completion Ring
The addition of unaligned chunks mode, the documentation needs to be updated to indicate that the incoming addr to the fill ring will only be masked if the user application is run in the aligned chunk mode. This patch also adds a line to explicitly indicate that the incoming addr will not be masked if running the user application in the unaligned chunk mode. Signed-off-by: Kevin Laatz <kevin.laatz@intel.com> --- Documentation/networking/af_xdp.rst | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)