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| author | D. Wythe <alibuda@linux.alibaba.com> | 2026-04-29 05:16:37 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-05-01 03:33:11 +0300 |
| commit | 4cc5130ee84adcc8904772df44d64e59727c72bd (patch) | |
| tree | 243faab364c92c7f8570d680003b8d565a8008a0 | |
| parent | 6855a52318b3a8c33031209e38bef497c971ef17 (diff) | |
| download | linux-4cc5130ee84adcc8904772df44d64e59727c72bd.tar.xz | |
net/smc: cap allocation order for SMC-R physically contiguous buffers
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 <alibuda@linux.alibaba.com>
Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Sidraya Jayagond <sidraya@linux.ibm.com>
Link: https://patch.msgid.link/20260429021637.21815-1-alibuda@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/smc/smc_core.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index e2d083daeb7e..cf6b620fef05 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) { |