* [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file @ 2019-09-11 13:28 Wei Yang 2019-09-11 13:28 ` [Qemu-devel] [PATCH V2 1/2] migration/qemu-file: remove check on writev_buffer in qemu_put_compression_data Wei Yang ` (2 more replies) 0 siblings, 3 replies; 5+ messages in thread From: Wei Yang @ 2019-09-11 13:28 UTC (permalink / raw) To: qemu-devel; +Cc: Wei Yang, dgilbert, quintela Two cleanup: Patch #1 make code consistent on calling add_to_iovec Patch #2 refine the code to handle the case when buf already flushed v2: * wrap common steps into add_buf_to_iovec() Wei Yang (2): migration/qemu-file: remove check on writev_buffer in qemu_put_compression_data migration/qemu-file: fix potential buf waste for extra buf_index adjustment migration/qemu-file.c | 45 ++++++++++++++++++++++++++------------------- 1 file changed, 26 insertions(+), 19 deletions(-) -- 2.15.1 ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH V2 1/2] migration/qemu-file: remove check on writev_buffer in qemu_put_compression_data 2019-09-11 13:28 [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file Wei Yang @ 2019-09-11 13:28 ` Wei Yang 2019-09-11 13:28 ` [Qemu-devel] [PATCH V2 2/2] migration/qemu-file: fix potential buf waste for extra buf_index adjustment Wei Yang 2019-09-12 10:23 ` [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file Dr. David Alan Gilbert 2 siblings, 0 replies; 5+ messages in thread From: Wei Yang @ 2019-09-11 13:28 UTC (permalink / raw) To: qemu-devel; +Cc: Wei Yang, dgilbert, quintela From: Wei Yang <richardw.yang@linux.intel.com> The check of writev_buffer is in qemu_fflush, which means it is not harmful if it is NULL. And removing it will make the code consistent since all other add_to_iovec() is called without the check. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- migration/qemu-file.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/migration/qemu-file.c b/migration/qemu-file.c index e33c46764f..47f16d0e54 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -761,9 +761,7 @@ ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream, } qemu_put_be32(f, blen); - if (f->ops->writev_buffer) { - add_to_iovec(f, f->buf + f->buf_index, blen, false); - } + add_to_iovec(f, f->buf + f->buf_index, blen, false); f->buf_index += blen; if (f->buf_index == IO_BUF_SIZE) { qemu_fflush(f); -- 2.15.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH V2 2/2] migration/qemu-file: fix potential buf waste for extra buf_index adjustment 2019-09-11 13:28 [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file Wei Yang 2019-09-11 13:28 ` [Qemu-devel] [PATCH V2 1/2] migration/qemu-file: remove check on writev_buffer in qemu_put_compression_data Wei Yang @ 2019-09-11 13:28 ` Wei Yang 2019-09-11 19:01 ` Dr. David Alan Gilbert 2019-09-12 10:23 ` [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file Dr. David Alan Gilbert 2 siblings, 1 reply; 5+ messages in thread From: Wei Yang @ 2019-09-11 13:28 UTC (permalink / raw) To: qemu-devel; +Cc: Wei Yang, dgilbert, quintela From: Wei Yang <richardw.yang@linux.intel.com> In add_to_iovec(), qemu_fflush() will be called if iovec is full. If this happens, buf_index is reset. Currently, this is not checked and buf_index would always been adjust with buf size. This is not harmful, but will waste some space in file buffer. This patch make add_to_iovec() return 1 when it has flushed the file. Then the caller could check the return value to see whether it is necessary to adjust the buf_index any more. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> --- v2: * wrap these common steps into add_buf_to_iovec() --- migration/qemu-file.c | 43 ++++++++++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 17 deletions(-) diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 47f16d0e54..417eeba64b 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -382,8 +382,16 @@ int qemu_fclose(QEMUFile *f) return ret; } -static void add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size, - bool may_free) +/* + * Add buf to iovec. Do flush if iovec is full. + * + * Return values: + * 1 iovec is full and flushed + * 0 iovec is not flushed + * + */ +static int add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size, + bool may_free) { /* check for adjacent buffer and coalesce them */ if (f->iovcnt > 0 && buf == f->iov[f->iovcnt - 1].iov_base + @@ -401,6 +409,19 @@ static void add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size, if (f->iovcnt >= MAX_IOV_SIZE) { qemu_fflush(f); + return 1; + } + + return 0; +} + +static void add_buf_to_iovec(QEMUFile *f, size_t len) +{ + if (!add_to_iovec(f, f->buf + f->buf_index, len, false)) { + f->buf_index += len; + if (f->buf_index == IO_BUF_SIZE) { + qemu_fflush(f); + } } } @@ -430,11 +451,7 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size) } memcpy(f->buf + f->buf_index, buf, l); f->bytes_xfer += l; - add_to_iovec(f, f->buf + f->buf_index, l, false); - f->buf_index += l; - if (f->buf_index == IO_BUF_SIZE) { - qemu_fflush(f); - } + add_buf_to_iovec(f, l); if (qemu_file_get_error(f)) { break; } @@ -451,11 +468,7 @@ void qemu_put_byte(QEMUFile *f, int v) f->buf[f->buf_index] = v; f->bytes_xfer++; - add_to_iovec(f, f->buf + f->buf_index, 1, false); - f->buf_index++; - if (f->buf_index == IO_BUF_SIZE) { - qemu_fflush(f); - } + add_buf_to_iovec(f, 1); } void qemu_file_skip(QEMUFile *f, int size) @@ -761,11 +774,7 @@ ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream, } qemu_put_be32(f, blen); - add_to_iovec(f, f->buf + f->buf_index, blen, false); - f->buf_index += blen; - if (f->buf_index == IO_BUF_SIZE) { - qemu_fflush(f); - } + add_buf_to_iovec(f, blen); return blen + sizeof(int32_t); } -- 2.15.1 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH V2 2/2] migration/qemu-file: fix potential buf waste for extra buf_index adjustment 2019-09-11 13:28 ` [Qemu-devel] [PATCH V2 2/2] migration/qemu-file: fix potential buf waste for extra buf_index adjustment Wei Yang @ 2019-09-11 19:01 ` Dr. David Alan Gilbert 0 siblings, 0 replies; 5+ messages in thread From: Dr. David Alan Gilbert @ 2019-09-11 19:01 UTC (permalink / raw) To: Wei Yang; +Cc: Wei Yang, qemu-devel, quintela * Wei Yang (richard.weiyang@gmail.com) wrote: > From: Wei Yang <richardw.yang@linux.intel.com> > > In add_to_iovec(), qemu_fflush() will be called if iovec is full. If > this happens, buf_index is reset. Currently, this is not checked and > buf_index would always been adjust with buf size. > > This is not harmful, but will waste some space in file buffer. > > This patch make add_to_iovec() return 1 when it has flushed the file. > Then the caller could check the return value to see whether it is > necessary to adjust the buf_index any more. > > Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > > --- > v2: > * wrap these common steps into add_buf_to_iovec() > --- > migration/qemu-file.c | 43 ++++++++++++++++++++++++++----------------- > 1 file changed, 26 insertions(+), 17 deletions(-) > > diff --git a/migration/qemu-file.c b/migration/qemu-file.c > index 47f16d0e54..417eeba64b 100644 > --- a/migration/qemu-file.c > +++ b/migration/qemu-file.c > @@ -382,8 +382,16 @@ int qemu_fclose(QEMUFile *f) > return ret; > } > > -static void add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size, > - bool may_free) > +/* > + * Add buf to iovec. Do flush if iovec is full. > + * > + * Return values: > + * 1 iovec is full and flushed > + * 0 iovec is not flushed > + * > + */ > +static int add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size, > + bool may_free) > { > /* check for adjacent buffer and coalesce them */ > if (f->iovcnt > 0 && buf == f->iov[f->iovcnt - 1].iov_base + > @@ -401,6 +409,19 @@ static void add_to_iovec(QEMUFile *f, const uint8_t *buf, size_t size, > > if (f->iovcnt >= MAX_IOV_SIZE) { > qemu_fflush(f); > + return 1; > + } > + > + return 0; > +} > + > +static void add_buf_to_iovec(QEMUFile *f, size_t len) > +{ > + if (!add_to_iovec(f, f->buf + f->buf_index, len, false)) { > + f->buf_index += len; > + if (f->buf_index == IO_BUF_SIZE) { > + qemu_fflush(f); > + } Yep, that's better. Dave > } > } > > @@ -430,11 +451,7 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size) > } > memcpy(f->buf + f->buf_index, buf, l); > f->bytes_xfer += l; > - add_to_iovec(f, f->buf + f->buf_index, l, false); > - f->buf_index += l; > - if (f->buf_index == IO_BUF_SIZE) { > - qemu_fflush(f); > - } > + add_buf_to_iovec(f, l); > if (qemu_file_get_error(f)) { > break; > } > @@ -451,11 +468,7 @@ void qemu_put_byte(QEMUFile *f, int v) > > f->buf[f->buf_index] = v; > f->bytes_xfer++; > - add_to_iovec(f, f->buf + f->buf_index, 1, false); > - f->buf_index++; > - if (f->buf_index == IO_BUF_SIZE) { > - qemu_fflush(f); > - } > + add_buf_to_iovec(f, 1); > } > > void qemu_file_skip(QEMUFile *f, int size) > @@ -761,11 +774,7 @@ ssize_t qemu_put_compression_data(QEMUFile *f, z_stream *stream, > } > > qemu_put_be32(f, blen); > - add_to_iovec(f, f->buf + f->buf_index, blen, false); > - f->buf_index += blen; > - if (f->buf_index == IO_BUF_SIZE) { > - qemu_fflush(f); > - } > + add_buf_to_iovec(f, blen); > return blen + sizeof(int32_t); > } > > -- > 2.15.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file 2019-09-11 13:28 [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file Wei Yang 2019-09-11 13:28 ` [Qemu-devel] [PATCH V2 1/2] migration/qemu-file: remove check on writev_buffer in qemu_put_compression_data Wei Yang 2019-09-11 13:28 ` [Qemu-devel] [PATCH V2 2/2] migration/qemu-file: fix potential buf waste for extra buf_index adjustment Wei Yang @ 2019-09-12 10:23 ` Dr. David Alan Gilbert 2 siblings, 0 replies; 5+ messages in thread From: Dr. David Alan Gilbert @ 2019-09-12 10:23 UTC (permalink / raw) To: Wei Yang; +Cc: qemu-devel, quintela * Wei Yang (richard.weiyang@gmail.com) wrote: > Two cleanup: > > Patch #1 make code consistent on calling add_to_iovec > Patch #2 refine the code to handle the case when buf already flushed Queued > v2: > * wrap common steps into add_buf_to_iovec() > > Wei Yang (2): > migration/qemu-file: remove check on writev_buffer in > qemu_put_compression_data > migration/qemu-file: fix potential buf waste for extra buf_index > adjustment > > migration/qemu-file.c | 45 ++++++++++++++++++++++++++------------------- > 1 file changed, 26 insertions(+), 19 deletions(-) > > -- > 2.15.1 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-09-12 10:27 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-09-11 13:28 [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file Wei Yang 2019-09-11 13:28 ` [Qemu-devel] [PATCH V2 1/2] migration/qemu-file: remove check on writev_buffer in qemu_put_compression_data Wei Yang 2019-09-11 13:28 ` [Qemu-devel] [PATCH V2 2/2] migration/qemu-file: fix potential buf waste for extra buf_index adjustment Wei Yang 2019-09-11 19:01 ` Dr. David Alan Gilbert 2019-09-12 10:23 ` [Qemu-devel] [PATCH V2 0/2] migration/qemu-file: cleanup and refine qemu-file Dr. David Alan Gilbert
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