[jira] [Commented] (TS-4234) ATS on AARCH64 use spinlock for SSL locking

["Leif Hedstrom (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/TS-4234?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15169720#comment-15169720 ] 

Leif Hedstrom commented on TS-4234:
-----------------------------------

Can you put this on a github pull request please? Also, the header on any new files should include the normal ASF license blurb (just copy from any existing C / C++ file).

> ATS on AARCH64 use spinlock for SSL locking
> -------------------------------------------
>
>                 Key: TS-4234
>                 URL: https://issues.apache.org/jira/browse/TS-4234
>             Project: Traffic Server
>          Issue Type: Improvement
>          Components: SSL
>            Reporter: Shay Gal-On
>
> Currently on aarch64 mutex locking can be slower then necessary under load. The patch below adds an option to substitute the mutex in ssl locking callback with a spinlock using gcc intrinsics.
> diff -Nau -x Makefile -x .Tpo -x .deps orig-trafficserver-5.3.2/iocore/net/SSLUtils.cc trafficserver-5.3.2/iocore/net/SSLUtils.cc
> --- orig-trafficserver-5.3.2/iocore/net/SSLUtils.cc     2015-09-08 13:05:06.000000000 -0700
> +++ trafficserver-5.3.2/iocore/net/SSLUtils.cc  2016-02-26 11:44:55.709451000 -0800
> @@ -119,9 +119,17 @@
>  #endif
> -static pthread_mutex_t *mutex_buf = NULL;
>  static bool open_ssl_initialized = false;
> +#ifdef SSL_USE_SPINLOCK
> +#include "Spinlock.h"
> +#define SSL_locking_callback SSL_locking_callback_spinlock
> +static Spinlock *spinlock_buf = NULL;
> +#else
> +#define SSL_locking_callback SSL_locking_callback_mutex
> +static pthread_mutex_t *mutex_buf = NULL;
> +#endif
> +
>  RecRawStatBlock *ssl_rsb = NULL;
>  static InkHashTable *ssl_cipher_name_table = NULL;
> @@ -135,9 +143,24 @@
>  {
>    return (unsigned long)pthread_self();
>  }
> +#ifdef SSL_USE_SPINLOCK
> +static void
> +SSL_locking_callback_spinlock(int mode, int type, const char * /* file ATS_UNUSED */, int /* line ATS_UNUSED */)
> +{
> +  ink_assert(type < CRYPTO_num_locks());
> +  if (mode & CRYPTO_LOCK) {
> +       spinlock_buf[type].lock();
> +  } else if (mode & CRYPTO_UNLOCK) {
> +       spinlock_buf[type].unlock();
> +  } else {
> +    Debug("ssl", "invalid SSL locking mode 0x%x", mode);
> +    ink_assert(0);
> +  }
> +}
> +#else
>  static void
> -SSL_locking_callback(int mode, int type, const char * /* file ATS_UNUSED */, int /* line ATS_UNUSED */)
> +SSL_locking_callback_mutex(int mode, int type, const char * /* file ATS_UNUSED */, int /* line ATS_UNUSED */)
>  {
>    ink_assert(type < CRYPTO_num_locks());
> @@ -150,6 +173,7 @@
>      ink_assert(0);
>    }
>  }
> +#endif
>  static bool
>  SSL_CTX_add_extra_chain_cert_file(SSL_CTX *ctx, const char *chainfile)
> @@ -758,11 +782,14 @@
>      SSL_load_error_strings();
>      SSL_library_init();
> +#ifdef SSL_USE_SPINLOCK
> +    spinlock_buf = new Spinlock[CRYPTO_num_locks()];
> +#else
>      mutex_buf = (pthread_mutex_t *)OPENSSL_malloc(CRYPTO_num_locks() * sizeof(pthread_mutex_t));
> -
>      for (int i = 0; i < CRYPTO_num_locks(); i++) {
>        pthread_mutex_init(&mutex_buf[i], NULL);
>      }
> +#endif
>      CRYPTO_set_locking_callback(SSL_locking_callback);
>      CRYPTO_set_id_callback(SSL_pthreads_thread_id);
> diff -Nau -x Makefile -x .Tpo -x .deps orig-trafficserver-5.3.2/iocore/net/Spinlock.h trafficserver-5.3.2/iocore/net/Spinlock.h
> --- orig-trafficserver-5.3.2/iocore/net/Spinlock.h      1969-12-31 16:00:00.000000000 -0800
> +++ trafficserver-5.3.2/iocore/net/Spinlock.h   2016-02-26 11:34:06.359451000 -0800
> @@ -0,0 +1,38 @@
> +/** @file
> +
> +Author: Shay Gal-On
> +
> +A class implementing a simple spinlock using GCC atomics,
> +using sched_yield while lock fails.
> +
> +*/
> +
> +#include <sched.h>
> +
> +class Spinlock
> +{
> +public:
> +    int _data;
> +
> +public:
> +    bool try_lock()
> +    {
> +        int r = __sync_lock_test_and_set( &_data, 1 );
> +        return r == 0;
> +    }
> +
> +    void lock()
> +    {
> +        for( unsigned k = 0; !try_lock(); ++k )
> +        {
> +                 sched_yield();
> +        }
> +    }
> +
> +    void unlock()
> +    {
> +        __sync_lock_release( &_data );
> +    }
> +};
> +
> +



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)