| Message ID | 1308557567-27600-1-git-send-email-avi@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 2011-06-20 10:12, Avi Kivity wrote: > When running kvm-autotest, fputc() is often the second highest (sometimes #1) > function showing up in a profile. This is due to fputc() locking the file > for every byte written. > > Optimize by buffering a line's worth of pixels and writing that out in a > single call. > > Signed-off-by: Avi Kivity <avi@redhat.com> > --- > > v2: drop unportable fputc_unlocked > > hw/vga.c | 13 ++++++++++--- > 1 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/hw/vga.c b/hw/vga.c > index d5bc582..97c96bf 100644 > --- a/hw/vga.c > +++ b/hw/vga.c > @@ -2349,15 +2349,19 @@ int ppm_save(const char *filename, struct DisplaySurface *ds) > uint32_t v; > int y, x; > uint8_t r, g, b; > + int ret; > + char *linebuf, *pbuf; > > f = fopen(filename, "wb"); > if (!f) > return -1; > fprintf(f, "P6\n%d %d\n%d\n", > ds->width, ds->height, 255); > + linebuf = qemu_malloc(ds->width * 3); > d1 = ds->data; > for(y = 0; y < ds->height; y++) { > d = d1; > + pbuf = linebuf; > for(x = 0; x < ds->width; x++) { > if (ds->pf.bits_per_pixel == 32) > v = *(uint32_t *)d; > @@ -2369,13 +2373,16 @@ int ppm_save(const char *filename, struct DisplaySurface *ds) > (ds->pf.gmax + 1); > b = ((v >> ds->pf.bshift) & ds->pf.bmax) * 256 / > (ds->pf.bmax + 1); > - fputc(r, f); > - fputc(g, f); > - fputc(b, f); > + *pbuf++ = r; > + *pbuf++ = g; > + *pbuf++ = b; > d += ds->pf.bytes_per_pixel; > } > d1 += ds->linesize; > + ret = fwrite(linebuf, 1, pbuf - linebuf, f); > + (void)ret; > } > + qemu_free(linebuf); > fclose(f); > return 0; > } Unrelated to this patch, but why is this function located in vga.c and not in console.c? Jan
On 06/20/2011 03:33 PM, Jan Kiszka wrote: > > --- a/hw/vga.c > > +++ b/hw/vga.c > > @@ -2349,15 +2349,19 @@ int ppm_save(const char *filename, struct DisplaySurface *ds) > Unrelated to this patch, but why is this function located in vga.c and > not in console.c? It's located in omap_lcdc.c as well. But it needs to be fully generalized to be moved out (handle all PixelFormats).
On Mon, Jun 20, 2011 at 9:12 AM, Avi Kivity <avi@redhat.com> wrote: > When running kvm-autotest, fputc() is often the second highest (sometimes #1) > function showing up in a profile. This is due to fputc() locking the file > for every byte written. > > Optimize by buffering a line's worth of pixels and writing that out in a > single call. > > Signed-off-by: Avi Kivity <avi@redhat.com> > --- > > v2: drop unportable fputc_unlocked > > hw/vga.c | 13 ++++++++++--- > 1 files changed, 10 insertions(+), 3 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
On 06/20/2011 03:12 AM, Avi Kivity wrote: > When running kvm-autotest, fputc() is often the second highest (sometimes #1) > function showing up in a profile. This is due to fputc() locking the file > for every byte written. > > Optimize by buffering a line's worth of pixels and writing that out in a > single call. > > Signed-off-by: Avi Kivity<avi@redhat.com> Applied. Thanks. Regards, Anthony Liguori > --- > > v2: drop unportable fputc_unlocked > > hw/vga.c | 13 ++++++++++--- > 1 files changed, 10 insertions(+), 3 deletions(-) > > diff --git a/hw/vga.c b/hw/vga.c > index d5bc582..97c96bf 100644 > --- a/hw/vga.c > +++ b/hw/vga.c > @@ -2349,15 +2349,19 @@ int ppm_save(const char *filename, struct DisplaySurface *ds) > uint32_t v; > int y, x; > uint8_t r, g, b; > + int ret; > + char *linebuf, *pbuf; > > f = fopen(filename, "wb"); > if (!f) > return -1; > fprintf(f, "P6\n%d %d\n%d\n", > ds->width, ds->height, 255); > + linebuf = qemu_malloc(ds->width * 3); > d1 = ds->data; > for(y = 0; y< ds->height; y++) { > d = d1; > + pbuf = linebuf; > for(x = 0; x< ds->width; x++) { > if (ds->pf.bits_per_pixel == 32) > v = *(uint32_t *)d; > @@ -2369,13 +2373,16 @@ int ppm_save(const char *filename, struct DisplaySurface *ds) > (ds->pf.gmax + 1); > b = ((v>> ds->pf.bshift)& ds->pf.bmax) * 256 / > (ds->pf.bmax + 1); > - fputc(r, f); > - fputc(g, f); > - fputc(b, f); > + *pbuf++ = r; > + *pbuf++ = g; > + *pbuf++ = b; > d += ds->pf.bytes_per_pixel; > } > d1 += ds->linesize; > + ret = fwrite(linebuf, 1, pbuf - linebuf, f); > + (void)ret; > } > + qemu_free(linebuf); > fclose(f); > return 0; > }
Am 20.06.2011 um 15:11 schrieb Avi Kivity: > On 06/20/2011 03:33 PM, Jan Kiszka wrote: >> > --- a/hw/vga.c >> > +++ b/hw/vga.c >> > @@ -2349,15 +2349,19 @@ int ppm_save(const char *filename, >> struct DisplaySurface *ds) > >> Unrelated to this patch, but why is this function located in vga.c >> and >> not in console.c? > > It's located in omap_lcdc.c as well. But it needs to be fully > generalized to be moved out (handle all PixelFormats). For the record, there's a similar function in tcx.c as well, and I have one coming in ibm8514.c. Andreas
On Thu, Jun 23, 2011 at 12:22 AM, Andreas Färber <andreas.faerber@web.de> wrote: > Am 20.06.2011 um 15:11 schrieb Avi Kivity: > >> On 06/20/2011 03:33 PM, Jan Kiszka wrote: >>> >>> > --- a/hw/vga.c >>> > +++ b/hw/vga.c >>> > @@ -2349,15 +2349,19 @@ int ppm_save(const char *filename, struct >>> > DisplaySurface *ds) >> >>> Unrelated to this patch, but why is this function located in vga.c and >>> not in console.c? >> >> It's located in omap_lcdc.c as well. But it needs to be fully >> generalized to be moved out (handle all PixelFormats). > > For the record, there's a similar function in tcx.c as well, and I have one > coming in ibm8514.c. The screen dumpers generate their output based on the current state of the graphics card and the VRAM, this is why they are device specific. A generic screen dumper (if possible) would read the data from display surface. Maybe this should be done at the SDL/VNC/Spice/curses/dummy level, but the output shouldn't change depending on the back end in question.
diff --git a/hw/vga.c b/hw/vga.c index d5bc582..97c96bf 100644 --- a/hw/vga.c +++ b/hw/vga.c @@ -2349,15 +2349,19 @@ int ppm_save(const char *filename, struct DisplaySurface *ds) uint32_t v; int y, x; uint8_t r, g, b; + int ret; + char *linebuf, *pbuf; f = fopen(filename, "wb"); if (!f) return -1; fprintf(f, "P6\n%d %d\n%d\n", ds->width, ds->height, 255); + linebuf = qemu_malloc(ds->width * 3); d1 = ds->data; for(y = 0; y < ds->height; y++) { d = d1; + pbuf = linebuf; for(x = 0; x < ds->width; x++) { if (ds->pf.bits_per_pixel == 32) v = *(uint32_t *)d; @@ -2369,13 +2373,16 @@ int ppm_save(const char *filename, struct DisplaySurface *ds) (ds->pf.gmax + 1); b = ((v >> ds->pf.bshift) & ds->pf.bmax) * 256 / (ds->pf.bmax + 1); - fputc(r, f); - fputc(g, f); - fputc(b, f); + *pbuf++ = r; + *pbuf++ = g; + *pbuf++ = b; d += ds->pf.bytes_per_pixel; } d1 += ds->linesize; + ret = fwrite(linebuf, 1, pbuf - linebuf, f); + (void)ret; } + qemu_free(linebuf); fclose(f); return 0; }
When running kvm-autotest, fputc() is often the second highest (sometimes #1) function showing up in a profile. This is due to fputc() locking the file for every byte written. Optimize by buffering a line's worth of pixels and writing that out in a single call. Signed-off-by: Avi Kivity <avi@redhat.com> --- v2: drop unportable fputc_unlocked hw/vga.c | 13 ++++++++++--- 1 files changed, 10 insertions(+), 3 deletions(-)