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| author | Eric Dumazet <edumazet@google.com> | 2020-11-24 12:38:22 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-11-25 11:28:12 -0800 |
| commit | 2543a6000e593a213fba5b504f52c07e09f39835 (patch) | |
| tree | 74cded007848826335fa87abc2f7a749d3e469d2 /net/core | |
| parent | 12a8fe56c0f06eaab1f9d89d246c3591bcc7a966 (diff) | |
| download | linux-2543a6000e593a213fba5b504f52c07e09f39835.tar.gz linux-2543a6000e593a213fba5b504f52c07e09f39835.tar.bz2 linux-2543a6000e593a213fba5b504f52c07e09f39835.zip | |
gro_cells: reduce number of synchronize_net() calls
After cited commit, gro_cells_destroy() became damn slow
on hosts with a lot of cores.
This is because we have one additional synchronize_net() per cpu as
stated in the changelog.
gro_cells_init() is setting NAPI_STATE_NO_BUSY_POLL, and this was enough
to not have one synchronize_net() call per netif_napi_del()
We can factorize all the synchronize_net() to a single one,
right before freeing per-cpu memory.
Fixes: 5198d545dba8 ("net: remove napi_hash_del() from driver-facing API")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20201124203822.1360107-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/gro_cells.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/core/gro_cells.c b/net/core/gro_cells.c index e095fb871d91..6eb2e5ec2c50 100644 --- a/net/core/gro_cells.c +++ b/net/core/gro_cells.c @@ -99,9 +99,14 @@ void gro_cells_destroy(struct gro_cells *gcells) struct gro_cell *cell = per_cpu_ptr(gcells->cells, i); napi_disable(&cell->napi); - netif_napi_del(&cell->napi); + __netif_napi_del(&cell->napi); __skb_queue_purge(&cell->napi_skbs); } + /* This barrier is needed because netpoll could access dev->napi_list + * under rcu protection. + */ + synchronize_net(); + free_percpu(gcells->cells); gcells->cells = NULL; } |