<html> <head> <meta content="text/html; charset=utf-8" http-equiv="Content-Type"> </head> <body text="#000000" bgcolor="#FFFFFF"> <div class="moz-cite-prefix">Am 21.07.2016 um 11:16 schrieb Wang, Qingqing: </div> <blockquote cite="mid:SN1PR12MB0511612A271156A2EFC7B449EC090@SN1PR12MB0511.namprd12.prod.outlook.com" type="cite"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Exchange Server">  <style></style> <meta content="text/html; charset=UTF-8"> <style type="text/css" style="">  </style> <div dir="ltr"> <div id="x_divtagdefaultwrapper" style="font-size:12pt; color:#000000; background-color:#FFFFFF; font-family:Calibri,Arial,Helvetica,sans-serif"> This doesn't work on 32bit systems since totalram is a long (IIRC) and so this will certainly overflow. -- can you be more specific, how could the overflow happen? </div> </div> </blockquote> Both values are 32bit on a 32bit system, so as soon as you have more than 4GB installed this will overflow. You need to cast the long to a 64bit value to avoid that. <blockquote cite="mid:SN1PR12MB0511612A271156A2EFC7B449EC090@SN1PR12MB0511.namprd12.prod.outlook.com" type="cite"> <div dir="ltr"> <div id="x_divtagdefaultwrapper" style="font-size:12pt; color:#000000; background-color:#FFFFFF; font-family:Calibri,Arial,Helvetica,sans-serif"> Additional if I remember correctly we didn't ended the discussion on what to do here with a conclusion. -- ok, since it happens in anther mail list, we should stop talking about it here, you can send out your ideas there. </div> </div> </blockquote> Actually that discussion was held long ago internally but we never got a conclusion on this IIRC. So we should probably continue the discussion on this thread now. Regards, Christian. <blockquote cite="mid:SN1PR12MB0511612A271156A2EFC7B449EC090@SN1PR12MB0511.namprd12.prod.outlook.com" type="cite"> <div dir="ltr"> <div id="x_divtagdefaultwrapper" style="font-size:12pt; color:#000000; background-color:#FFFFFF; font-family:Calibri,Arial,Helvetica,sans-serif"> </div> <hr tabindex="-1" style="display:inline-block; width:98%"> <div id="x_divRplyFwdMsg" dir="ltr">发件人: amd-gfx <a class="moz-txt-link-rfc2396E" href="mailto:amd-gfx-bounces@lists.freedesktop.org"><amd-gfx-bounces@lists.freedesktop.org></a> 代表 Christian König <a class="moz-txt-link-rfc2396E" href="mailto:deathsimple@vodafone.de"><deathsimple@vodafone.de></a> 发送时间: 2016年7月21日 16:53:05 收件人: Wang, Qingqing; <a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a> 主题: Re: [PATCH] drm/amdgpu: adjust gtt memory size <div> </div> </div> </div> <div class="PlainText">Am 21.07.2016 um 09:46 schrieb Ken Wang: > Change-Id: If00d5b97ba9e30f9b7f68fdfc134a0f8b3ad2add > Signed-off-by: Ken Wang <a class="moz-txt-link-rfc2396E" href="mailto:Qingqing.Wang@amd.com"><Qingqing.Wang@amd.com></a> > --- > drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c | 7 ++++++- > drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c | 7 ++++++- > 2 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c > index a3b6048..0b095d5 100644 > --- a/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c > +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v7_0.c > @@ -336,6 +336,11 @@ static int gmc_v7_0_mc_init(struct amdgpu_device *adev) > { > u32 tmp; > int chansize, numchan; > + u64 sysmem_size; > + struct sysinfo si; > + > + si_meminfo(&si); > + sysmem_size = si.totalram * si.mem_unit; This doesn't work on 32bit systems since totalram is a long (IIRC) and so this will certainly overflow. Additional if I remember correctly we didn't ended the discussion on what to do here with a conclusion. Regards, Christian. > > /* Get VRAM informations */ > tmp = RREG32(mmMC_ARB_RAMCFG); > @@ -392,7 +397,7 @@ static int gmc_v7_0_mc_init(struct amdgpu_device *adev) > * size equal to the 1024 or vram, whichever is larger. > */ > if (amdgpu_gart_size == -1) > - adev->mc.gtt_size = max((1024ULL << 20), adev->mc.mc_vram_size); > + adev->mc.gtt_size = max((1024ULL << 20), min(adev->mc.mc_vram_size, sysmem_size/2)); > else > adev->mc.gtt_size = (uint64_t)amdgpu_gart_size << 20; > > diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c > index 02b6872..790bf7a 100644 > --- a/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c > +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v8_0.c > @@ -413,6 +413,11 @@ static int gmc_v8_0_mc_init(struct amdgpu_device *adev) > { > u32 tmp; > int chansize, numchan; > + u64 sysmem_size; > + struct sysinfo si; > + > + si_meminfo(&si); > + sysmem_size = si.totalram * si.mem_unit; > > /* Get VRAM informations */ > tmp = RREG32(mmMC_ARB_RAMCFG); > @@ -469,7 +474,7 @@ static int gmc_v8_0_mc_init(struct amdgpu_device *adev) > * size equal to the 1024 or vram, whichever is larger. > */ > if (amdgpu_gart_size == -1) > - adev->mc.gtt_size = max((1024ULL << 20), adev->mc.mc_vram_size); > + adev->mc.gtt_size = max((1024ULL << 20), min(adev->mc.mc_vram_size, sysmem_size/2)); > else > adev->mc.gtt_size = (uint64_t)amdgpu_gart_size << 20; > _______________________________________________ amd-gfx mailing list <a class="moz-txt-link-abbreviated" href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a> <a moz-do-not-send="true" href="https://lists.freedesktop.org/mailman/listinfo/amd-gfx">https://lists.freedesktop.org/mailman/listinfo/amd-gfx</a> </div> </blockquote> </body> </html>