https://gcc.gnu.org/g:b2375795197480ba1c28fbcf8f827442061b83ed
commit b2375795197480ba1c28fbcf8f827442061b83ed Author: Tobias Burnus <[email protected]> Date: Tue Jun 9 08:21:18 2026 +0200 libgomp.texi: Mention ROCR_VISIBLE_DEVICES in context of USM Re-add half-sentence that got lost in commit r16-5799-gfe5c59ea997316. Currently, USM is only supported if all AMD GPUs support USM; hence, on a mixed system (e.g. CPU with GPU of type APU plus separate, discrete GPU not supporting USM/SVM), host fallback always happens. Workaround is to use ROCR_VISIBLE_DEVICES. Additionally, the "not-supported" wording should refer here to USM/SVM support not to XNACK, which has been clarified here. libgomp/ChangeLog: * libgomp.texi (GCN): Mention ROCR_VISIBLE_DEVICES. (cherry picked from commit b6f7035408cc08acef6f05a65d5da1d5f9e29a33) Diff: --- libgomp/libgomp.texi | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/libgomp/libgomp.texi b/libgomp/libgomp.texi index 869ced1afb3a..05de63e4020c 100644 --- a/libgomp/libgomp.texi +++ b/libgomp/libgomp.texi @@ -7667,8 +7667,10 @@ The implementation remark: true, in which case the runtime will attempt to set the @code{HSA_XNACK} environment variable to @samp{1} automatically (user-set values are not overridden, and the setting only affects the executable itself and any - child processes). If any AMD GPU device is not supported, all AMD GPUs - are removed from the list of available devices (``host fallback''). + child processes). If any AMD GPU device does not support unified-shared + memory, all AMD GPUs are removed from the list of available devices + (``host fallback''); consider using @code{ROCR_VISIBLE_DEVICES} to only + enable devices supporting it. @item The available stack size can be changed using the @code{GCN_STACK_SIZE} environment variable; the default is 32 kiB per thread. @item Low-latency memory (@code{omp_low_lat_mem_space}) is supported when the
