The alloc_pages() cannot satisfy requests exceeding MAX_PAGE_ORDER, and attempting such allocations will lead to guaranteed failures and potential kernel warnings. For SMCR_PHYS_CONT_BUFS, cap the allocation order to MAX_PAGE_ORDER. This ensures the attempts to allocate the largest possible physically contiguous chunk succeed, instead of failing with an invalid order. This also avoids redundant "try-fail-degrade" cycles in __smc_buf_create(). For SMCR_MIXED_BUFS, no cap is needed: if the order exceeds MAX_PAGE_ORDER, alloc_pages() will silently fail (__GFP_NOWARN) and automatically fall back to virtual memory. Signed-off-by: D. Wythe Reviewed-by: Dust Li --- Changes v1 -> v2: https://lore.kernel.org/netdev/20260312082154.36971-1-alibuda@linux.alibaba.com/ - Move the bufsize cap from smcr_new_buf_create() up to __smc_buf_create(), which is simpler and avoids touching the allocation logic itself. --- net/smc/smc_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index e2d083daeb7e..cdd881746e21 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -2440,6 +2440,10 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb) /* use socket send buffer size (w/o overhead) as start value */ bufsize = smc->sk.sk_sndbuf / 2; + /* limit bufsize for physically contiguous buffers */ + if (!is_smcd && lgr->buf_type == SMCR_PHYS_CONT_BUFS) + bufsize = min_t(int, bufsize, (PAGE_SIZE << MAX_PAGE_ORDER)); + for (bufsize_comp = smc_compress_bufsize(bufsize, is_smcd, is_rmb); bufsize_comp >= 0; bufsize_comp--) { if (is_rmb) { -- 2.45.0