| Message ID | 20190128142410.11584-2-bsd@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Break down the MTP write operation | expand |
On 1/28/19 8:24 AM, Bandan Das wrote: > This is a "pre-patch" to breaking up the write buffer for > MTP writes. Instead of allocating a mtp buffer equal to size > sent by the initiator, we start with a small size and reallocate > multiples (of that small size) as needed. > > Signed-off-by: Bandan Das <bsd@redhat.com> > --- > hw/usb/dev-mtp.c | 26 ++++++++++++-------------- > 1 file changed, 12 insertions(+), 14 deletions(-) > > diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c > index 68c5eb8eaa..2f3536a26d 100644 > --- a/hw/usb/dev-mtp.c > +++ b/hw/usb/dev-mtp.c > @@ -152,7 +152,6 @@ struct MTPData { > bool first; > /* Used for >4G file sizes */ > bool pending; > - uint64_t cached_length; > int fd; > }; > > @@ -244,6 +243,7 @@ typedef struct { > > #define MTP_MANUFACTURER "QEMU" > #define MTP_PRODUCT "QEMU filesharing" > +#define MTP_WRITE_BUF_SZ 512000 Why a non-power-of-2 instead of using units.h and writing (512 * KiB)?
Eric Blake <eblake@redhat.com> writes: > On 1/28/19 8:24 AM, Bandan Das wrote: >> This is a "pre-patch" to breaking up the write buffer for >> MTP writes. Instead of allocating a mtp buffer equal to size >> sent by the initiator, we start with a small size and reallocate >> multiples (of that small size) as needed. >> >> Signed-off-by: Bandan Das <bsd@redhat.com> >> --- >> hw/usb/dev-mtp.c | 26 ++++++++++++-------------- >> 1 file changed, 12 insertions(+), 14 deletions(-) >> >> diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c >> index 68c5eb8eaa..2f3536a26d 100644 >> --- a/hw/usb/dev-mtp.c >> +++ b/hw/usb/dev-mtp.c >> @@ -152,7 +152,6 @@ struct MTPData { >> bool first; >> /* Used for >4G file sizes */ >> bool pending; >> - uint64_t cached_length; >> int fd; >> }; >> >> @@ -244,6 +243,7 @@ typedef struct { >> >> #define MTP_MANUFACTURER "QEMU" >> #define MTP_PRODUCT "QEMU filesharing" >> +#define MTP_WRITE_BUF_SZ 512000 > > Why a non-power-of-2 instead of using units.h and writing (512 * KiB)? Thank you for the reminder, Eric. I posted a v4.
diff --git a/hw/usb/dev-mtp.c b/hw/usb/dev-mtp.c index 68c5eb8eaa..2f3536a26d 100644 --- a/hw/usb/dev-mtp.c +++ b/hw/usb/dev-mtp.c @@ -152,7 +152,6 @@ struct MTPData { bool first; /* Used for >4G file sizes */ bool pending; - uint64_t cached_length; int fd; }; @@ -244,6 +243,7 @@ typedef struct { #define MTP_MANUFACTURER "QEMU" #define MTP_PRODUCT "QEMU filesharing" +#define MTP_WRITE_BUF_SZ 512000 enum { STR_MANUFACTURER = 1, @@ -1658,7 +1658,7 @@ static void usb_mtp_write_data(MTPState *s) d->fd = mkdir(path, mask); goto free; } - if ((s->dataset.size != 0xFFFFFFFF) && (s->dataset.size < d->length)) { + if ((s->dataset.size != 0xFFFFFFFF) && (s->dataset.size != d->offset)) { usb_mtp_queue_result(s, RES_STORE_FULL, d->trans, 0, 0, 0, 0); goto done; @@ -1776,17 +1776,21 @@ static void usb_mtp_get_data(MTPState *s, mtp_container *container, total_len = cpu_to_le32(container->length) - sizeof(mtp_container); /* Length of data in this packet */ data_len -= sizeof(mtp_container); - usb_mtp_realloc(d, total_len); - d->length += total_len; + if (total_len < MTP_WRITE_BUF_SZ) { + usb_mtp_realloc(d, total_len); + d->length += total_len; + } else { + usb_mtp_realloc(d, MTP_WRITE_BUF_SZ - sizeof(mtp_container)); + d->length += MTP_WRITE_BUF_SZ - sizeof(mtp_container); + } d->offset = 0; - d->cached_length = total_len; d->first = false; d->pending = false; } if (d->pending) { - usb_mtp_realloc(d, d->cached_length); - d->length += d->cached_length; + usb_mtp_realloc(d, MTP_WRITE_BUF_SZ); + d->length += MTP_WRITE_BUF_SZ; d->pending = false; } @@ -1794,12 +1798,6 @@ static void usb_mtp_get_data(MTPState *s, mtp_container *container, dlen = data_len; } else { dlen = d->length - d->offset; - /* Check for cached data for large files */ - if ((s->dataset.size == 0xFFFFFFFF) && (dlen < p->iov.size)) { - usb_mtp_realloc(d, p->iov.size - dlen); - d->length += p->iov.size - dlen; - dlen = p->iov.size; - } } switch (d->code) { @@ -1821,7 +1819,7 @@ static void usb_mtp_get_data(MTPState *s, mtp_container *container, d->offset += dlen; if ((p->iov.size % 64) || !p->iov.size) { assert((s->dataset.size == 0xFFFFFFFF) || - (s->dataset.size == d->length)); + (s->dataset.size == d->offset)); usb_mtp_write_data(s); usb_mtp_data_free(s->data_out);
This is a "pre-patch" to breaking up the write buffer for MTP writes. Instead of allocating a mtp buffer equal to size sent by the initiator, we start with a small size and reallocate multiples (of that small size) as needed. Signed-off-by: Bandan Das <bsd@redhat.com> --- hw/usb/dev-mtp.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-)