[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [PATCH] locking/x86/xen: Use try_cmpxchg() in xen_alloc_p2m_entry()
On 05.04.24 10:32, Uros Bizjak wrote: Use try_cmpxchg() instead of cmpxchg(*ptr, old, new) == old. The x86 CMPXCHG instruction returns success in the ZF flag, so this change saves a compare after CMPXCHG. Also, try_cmpxchg() implicitly assigns old *ptr value to "old" when CMPXCHG fails. There is no need to explicitly assign old *ptr value to the temporary, which can simplify the surrounding source code. No functional change intended. Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Juergen
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |